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How much area would renewable energy require?

Many people believe that we must use either fossil fuels or nuclear power for energy production, because renewable energy (solar, wind) takes up far too much land area.

For instance, consider Ivanpah’s Land Footprint: World’s Largest Thermal Project Requires 92 Times the Acreage of Babcock & Wilcox “Twin Pack”, by Ben Heard, 3/13/2014, The BreakThrough

The author points out that the land footprint of a solar power plant is 92 times larger than the land footprint of a small nuclear reactor.  He thus concludes that we need nuclear fission power, not solar.

Although I certainly agree that there are safe and responsible ways to generate power from nuclear fusion, the case against solar and wind power is overstated and doesn’t hold up to close analysis.

It turns out that the power needs of the entire United States could be filled by renewable energy that uses less than 1% of land area in the nation. Further, that land could even be dual-purpose. There are many places where people grow crops under and between solar panels or wind turbines.

Prof. Katharine Hayhoe writes

People worry about how much land we’d need to supply the US with clean energy. Well, @elonmusk and I have independently calculated it and we both come up with something roughly comparable to the area we currently use for maple syrup or golf. A square about 100-120 miles per side.

As a 🇨🇦 let me hasten to clarify that I’m not advocating for removing maple syrup production but rather for co-production of energy on land that is also used for farming or pollinator ecosystems 😁 For example, @FreshEnergy runs this amazing clearinghouse, The Center for Pollinators in Energy

Lands Use Area comparison USA

This graphic from Here’s How America Uses Its Land, By Dave Merrill and Lauren Leatherby, Bloomberg, 7/31/2018

“Land use classifications are based on data published in 2017 by the U.S. Department of Agriculture’s Economic Research Service in a report called the Major Uses of Land in the United States (MLU). Data from the report provide total land-use acreage estimates for each state across six broad categories. Those totals are displayed per 250,000 acres.”

Ramez Naam has a similar analysis, How Much Land Would it Take to Power the US via Solar?

Guest writer Ben Heard [see above] complains that solar’s land footprint (specifically at the Ivanpah plant) is 92 times that of a small modular nuclear reactor… What Heard’s Breakthrough Institute article doesn’t tell you is how tiny that land footprint, in the grand scheme of things, actually is. Do the math on the numbers he presents: 1087 Gwh / yr, or 0.31 Gwh / acre / year.

At that output, to meet the US electricity demand of 3.7 million Gwh per year, you’d need about 48,000 square kilometers of solar sites. (That’s total area, not just area of panels.) That may sound like a stunningly large area, and in some sense, it is. But it’s less than half the size of the Mojave desert. And more importantly, the continental United States has a land area of 7.6 million square kilometers. That implies to that meet US electrical demand via this real world example of Ivanpah, would require just 0.6 percent of the land area of the continental US.

Asked about this on twitter, Heard replied that larger size nevertheless is a disadvantage. It threatens ecosystems and endangered species, for instance. And this is a legitimate point, in some specific areas. (Though certainly far less so than coal and natural gas.)

But, for context, agriculture uses roughly 30% of all land in the United States, or 50 times as much land as would be needed to meet US electricity needs via solar.


The Discovery of Global Warming

The Discovery of Global Warming

Global warming GIF

Dr. Spencer Weart is a historian specializing in the history of modern physics and geophysics. Until his retirement in 2009 he was Director of the Center for History of Physics of the American Institute of Physics (AIP) in College Park, Maryland, USA, and he continues to be affiliated with the Center.

Spencer Weart writes in the summary overview to his book:

In 1896 the Swedish scientist Svante Arrhenius published a new idea. By burning fossil fuels such as coal, thus adding CO2 to Earth’s atmosphere, humanity would raise the planet’s average temperature. This “greenhouse effect,” as it later came to be called, was only one of many speculations about climate change, and not the most plausible. The few scientists who paid attention to Arrhenius used clumsy experiments and rough approximations to argue that our emissions could not change the planet. Most people thought it was already obvious that puny humanity could never affect the vast global climate cycles, which were governed by a benign “balance of nature.”

In the 1930s, measurements showed that the United States and North Atlantic region had warmed significantly during the previous half-century. Scientists supposed this was just a phase of some mild natural cycle, probably regional, with unknown causes. Only one lone voice, the English steam engineer and amateur scientist Guy Stewart Callendar, published arguments that greenhouse warming was underway. If so, he and most others thought it would be beneficial.

In the 1950s, Callendar’s claims provoked a few scientists to look into the question with far better techniques and calculations than earlier generations could have deployed. This research was made possible by a sharp increase of government funding, especially from military agencies that wanted to know more about the weather and geophysics in general. Not only might such knowledge be crucial in future battles, but scientific progress could bring a nation prestige in the Cold War competition. The new studies showed that, contrary to earlier crude assumptions, CO2 might indeed build up in the atmosphere and bring warming. In 1960 painstaking measurements of the level of the gas in the atmosphere by Charles Keeling, a young scientist with an obsession for accuracy, drove home the point. The level was in fact rising year by year.

(This essay covers only developments relating directly to carbon dioxide, with a separate essay for Other Greenhouse Gases. Theories are discussed in the essay on Simple Models of Climate.)

The Discovery of Global Warming: A hypertext history of how scientists came to (partly) understand what people are doing to cause climate change.


The Discovery of Global Warming: Revised and Expanded Edition, by Spencer R. Weart, Harvard University Press, 2008




This website is educational. Materials within it are being used in accord with the Fair Use doctrine, as defined by United States law.
§107. Limitations on Exclusive Rights: Fair Use. Notwithstanding the provisions of section 106, the fair use of a copyrighted work, including such use by reproduction in copies or phone records or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use, the factors to be considered shall include: the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes; the nature of the copyrighted work; the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and the effect of the use upon the potential market for or value of the copyrighted work. (added pub. l 94-553, Title I, 101, Oct 19, 1976, 90 Stat 2546)



Protecting New Orleans from rising water levels

New Orleans, Louisiana

This is a placeholder blogpost. The article is to be written

New Orleans canal gates flood control

Map: Google Maps. Photos by Mary Grace McKernan; infographic: by Marc Fusco.


New Orleans Lake Pontchartrain Elevation map to Mississippi River

Image by Midnightcomm for Wikipedia, public domain.


Apps & Interactive graphics

Louisiana’s Sea Level Is Rising: SeaLevelRise.org



Fortified But Still In Peril, New Orleans Braces for Its Future: In the years after Hurricane Katrina, over 350 miles of levees, flood walls, gates and pumps came to encircle greater New Orleans. Experts say that is not enough.

By John Schwartz and Mark Schleifstein, 2/24/2018

Fortified But Still In Peril, New Orleans Braces for Its Future

After a $14-Billion Upgrade, New Orleans’ Levees Are Sinking. Sea level rise and ground subsidence will render the flood barriers inadequate in just four years. By Thomas Frank, E&E News, Scientific American, 4/11,/2019

After a $14-Billion Upgrade, New Orleans’ Levees Are Sinking. Scientific American

Rising Sea Levels May Limit New Orleans Adaptation Efforts. New Orleans sees that even modern engineering cannot eliminate flooding risk. By Emily Holden, ClimateWire on September 10, 2015. Scientific American.

Rising Sea Levels May Limit New Orleans Adaptation Efforts. Scientific American

Fortified but still in peril, New Orleans braces for its future: Our Drowning Coast. By Mark Schleifstein | Posted February 24, 2018.

Fortified but still in peril, New Orleans braces for its future

Rising sea to displace 500,000 New Orleans area residents, study says; see where they might go. By Tristan Baurick, NOLA.com | The Times-Picayune. 4/20/2017.

A study published this week (April 2017) predicts that sea level rise will push hundreds of thousands of people out of U.S. coastal cities such as New Orleans. It says the population will boom in nearby inland cities such as Austin. The University of Georgia study is considered the first detailed look at how inland cities might be affected by sea level rise. It estimates more than than 500,000 people will flee the seven-parish New Orleans area by 2100 due to sea level rise and the problems that come with it, including frequent flooding and greater exposure to storm surges. That’s more than one third of metro New Orleans’s current population…. Across the United States, the study estimates, 13 million people will be displaced by sea level rise under a scenario in which some efforts are taken to mitigate the impacts of sea level rise. The biggest draw, it predicts, will be Austin, gaining 600,00 to 800,000 people on top of the metro area’s current estimated population of 2.1 million. Other inland cities likely to grow substantially include Orlando, Fla., Atlanta and Phoenix.

Rising sea to displace 500,000 New Orleans area residents, study says. NOLA.com

Migration induced by sea-level rise could reshape the US population landscape
Mathew E. Hauer. Nature Climate Change volume 7, pages 321–325 (2017)

Many sea-level rise (SLR) assessments focus on populations presently inhabiting vulnerable coastal communities, but to date no studies have attempted to model the destinations of these potentially displaced persons. With millions of potential future migrants in heavily populated coastal communities, SLR scholarship focusing solely on coastal communities characterizes SLR as primarily a coastal issue, obscuring the potential impacts in landlocked communities created by SLR-induced displacement. Here I address this issue by merging projected populations at risk of SLR with migration systems simulations to project future destinations of SLR migrants in the United States. I find that unmitigated SLR is expected to reshape the US population distribution, potentially stressing landlocked areas unprepared to accommodate this wave of coastal migrants—even after accounting for potential adaptation. These results provide the first glimpse of how climate change will reshape future population distributions and establish a new foundation for modelling potential migration destinations from climate stressors in an era of global environmental change.

Migration induced by sea-level rise could reshape the US population landscape (Nature, science journal)


How quickly can we reduce CO2 emissions

This is from Staffan Qvist (@QvistStaffan)
co-author of A BRIGHT FUTURE (PublicAffairs Books 2019).

If the world built clean power as aggressively as Germany (normalized by the size of the economy), how quickly would the global electricity grid be “cleaned up”? Answer (see graph) is unfortunately not encouraging, even disregarding nuke phase-out.

Time to get rid of using fossil fuels if more alternative energy


Time to get rid of using fossil fuels if more alternative energy 2



Climate Change Could Make Clouds Disappear, Triggering Cataclysmic Warming

Article archive for my students

A World Without Clouds, Natalie Wolchover, Quanta Magazine,

A state-of-the-art supercomputer simulation indicates that a feedback loop between global warming and cloud loss can push Earth’s climate past a disastrous tipping point in as little as a century.

On a 1987 voyage to the Antarctic, the paleoceanographer James Kennett and his crew dropped anchor in the Weddell Sea, drilled into the seabed, and extracted a vertical cylinder of sediment. In an inch-thick layer of plankton fossils and other detritus buried more than 500 feet deep, they found a disturbing clue about the planet’s past that could spell disaster for the future.

Lower in the sediment core, fossils abounded from 60 plankton species. But in that thin cross-section from about 56 million years ago, the number of species dropped to 17. And the planktons’ oxygen and carbon isotope compositions had dramatically changed. Kennett and his student Lowell Stott deduced from the anomalous isotopes that carbon dioxide had flooded the air, causing the ocean to rapidly acidify and heat up, in a process similar to what we are seeing today.

While those 17 kinds of plankton were sinking through the warming waters and settling on the Antarctic seabed, a tapir-like creature died in what is now Wyoming, depositing a tooth in a bright-red layer of sedimentary rock coursing through the badlands of the Bighorn Basin. In 1992, the finder of the tooth fossil, Phil Gingerich, and collaborators Jim Zachos and Paul Koch reported the same isotope anomalies in its enamel that Kennett and Stott had presented in their ocean findings a year earlier. The prehistoric mammal had also been breathing CO2-flooded air.

More data points surfaced in China, then Europe, then all over. A picture emerged of a brief, cataclysmic hot spell 56 million years ago, now known as the Paleocene-Eocene Thermal Maximum (PETM). After heat-trapping carbon leaked into the sky from an unknown source, the planet, which was already several degrees Celsius hotter than it is today, gained an additional 6 degrees. The ocean turned jacuzzi-hot near the equator and experienced mass extinctions worldwide. On land, primitive monkeys, horses and other early mammals marched northward, following vegetation to higher latitudes. The mammals also miniaturized over generations, as leaves became less nutritious in the carbonaceous air. Violent storms ravaged the planet; the geologic record indicates flash floods and protracted droughts. As Kennett put it, “Earth was triggered, and all hell broke loose.”

The PETM doesn’t only provide a past example of CO2-driven climate change; scientists say it also points to an unknown factor that has an outsize influence on Earth’s climate. When the planet got hot, it got really hot. Ancient warming episodes like the PETM were always far more extreme than theoretical models of the climate suggest they should have been. Even after accounting for differences in geography, ocean currents and vegetation during these past episodes, paleoclimatologists find that something big appears to be missing from their models — an X-factor whose wild swings leave no trace in the fossil record.

Evidence is mounting in favor of the answer that experts have long suspected but have only recently been capable of exploring in detail. “It’s quite clear at this point that the answer is clouds,” said Matt Huber, a paleoclimate modeler at Purdue University.

Clouds currently cover about two-thirds of the planet at any moment. But computer simulations of clouds have begun to suggest that as the Earth warms, clouds become scarcer. With fewer white surfaces reflecting sunlight back to space, the Earth gets even warmer, leading to more cloud loss. This feedback loop causes warming to spiral out of control.

For decades, rough calculations have suggested that cloud loss could significantly impact climate, but this concern remained speculative until the last few years, when observations and simulations of clouds improved to the point where researchers could amass convincing evidence.

Now, new findings reported today in the journal Nature Geoscience make the case that the effects of cloud loss are dramatic enough to explain ancient warming episodes like the PETM — and to precipitate future disaster. Climate physicists at the California Institute of Technology performed a state-of-the-art simulation of stratocumulus clouds, the low-lying, blankety kind that have by far the largest cooling effect on the planet.

The simulation revealed a tipping point: a level of warming at which stratocumulus clouds break up altogether. The disappearance occurs when the concentration of CO2 in the simulated atmosphere reaches 1,200 parts per million — a level that fossil fuel burning could push us past in about a century, under “business-as-usual” emissions scenarios. In the simulation, when the tipping point is breached, Earth’s temperature soars 8 degrees Celsius, in addition to the 4 degrees of warming or more caused by the CO2 directly.

Once clouds go away, the simulated climate “goes over a cliff,” said Kerry Emanuel, a climate scientist at the Massachusetts Institute of Technology. A leading authority on atmospheric physics, Emanuel called the new findings “very plausible,” though, as he noted, scientists must now make an effort to independently replicate the work.

To imagine 12 degrees of warming, think of crocodiles swimming in the Arctic and of the scorched, mostly lifeless equatorial regions during the PETM. If carbon emissions aren’t curbed quickly enough and the tipping point is breached, “that would be truly devastating climate change,” said Caltech’s Tapio Schneider, who performed the new simulation with Colleen Kaul and Kyle Pressel.

Huber said the stratocumulus tipping point helps explain the volatility that’s evident in the paleoclimate record. He thinks it might be one of many unknown instabilities in Earth’s climate. “Schneider and co-authors have cracked open Pandora’s box of potential climate surprises,” he said, adding that, as the mechanisms behind vanishing clouds become clear, “all of a sudden this enormous sensitivity that is apparent from past climates isn’t something that’s just in the past. It becomes a vision of the future.”

The Cloud Question

Clouds come in diverse shapes — sky-filling stratus, popcorn-puff cumulus, wispy cirrus, anvil-shaped nimbus and hybrids thereof — and span many physical scales. Made of microscopic droplets, they measure miles across and, collectively, cover most of the Earth’s surface. By blocking sunlight from reaching the surface, clouds cool the planet by several crucial degrees. And yet, they are insubstantial, woven into greatness by complicated physics. If the planet’s patchy white veil of clouds descended to the ground, it would make a watery sheen no thicker than a hair.

Clouds seem simple at first: They form when warm, humid air rises and cools. The water vapor in the air condenses around dust grains, sea salt or other particles, forming droplets of liquid water or ice — “cloud droplets.” But the picture grows increasingly complicated as heat, evaporation, turbulence, radiation, wind, geography and myriad other factors come into play.

Physicists have struggled since the 1960s to understand how global warming will affect the many different kinds of clouds, and how that will influence global warming in turn. For decades, clouds have been seen as by far the biggest source of uncertainty over how severe global warming will be — other than what society will do to reduce carbon emissions.

Kate Marvel contemplates the cloud question at the NASA Goddard Institute for Space Studies in New York City. Last spring, in her office several floors above Tom’s Restaurant on the Upper West Side, Marvel, wearing a cloud-patterned scarf, pointed to a plot showing the range of predictions made by different global climate models. The 30 or so models, run by climate research centers around the world, program in all the known factors to predict how much Earth’s temperature will increase as the CO2 level ticks up.

Each climate model solves a set of equations on a spherical grid representing Earth’s atmosphere. A supercomputer is used to evolve the grid of solutions forward in time, indicating how air and heat flow through each of the grid cells and circulate around the planet.

By adding carbon dioxide and other heat-trapping greenhouse gases to the simulated atmosphere and seeing what happens, scientists can predict Earth’s climate response. All the climate models include Earth’s ocean and wind currents and incorporate most of the important climate feedback loops, like the melting of the polar ice caps and the rise in humidity, which both exacerbate global warming. The models agree about most factors but differ greatly in how they try to represent clouds.

The least sensitive climate models, which predict the mildest reaction to increasing CO2, find that Earth will warm 2 degrees Celsius if the atmospheric CO2 concentration doubles relative to preindustrial times, which is currently on track to happen by about 2050. (The CO2concentration was 280 parts per million before fossil fuel burning began, and it’s above 410 ppm now.

So far, the average global temperature has risen 1 degree Celsius.) But the 2-degree prediction is the best-case scenario. “The thing that really freaks people out is this upper end here,” Marvel said, indicating projections of 4 or 5 degrees of warming in response to the doubling of CO2. “To put that in context, the difference between now and the last ice age was 4.5 degrees.”

The huge range in the models’ predictions chiefly comes down towhether they see clouds blocking more or less sunlight in the future. As Marvel put it, “You can fairly confidently say that the model spread in climate sensitivity is basically just a model spread in what clouds are going to do.”

Climate Change clouds feedback

Image from Lucy Reading-Ikkanda/Quanta Magazine

The problem is that, in computer simulations of the global climate, today’s supercomputers cannot resolve grid cells that are smaller than about 100 kilometers by 100 kilometers in area. But clouds are often no more than a few kilometers across. Physicists therefore have to simplify or “parameterize” clouds in their global models, assigning an overall level of cloudiness to each grid cell based on other properties, like temperature and humidity.

But clouds involve the interplay of so many mechanisms that it’s not obvious how best to parameterize them. The warming of the Earth and sky strengthens some mechanisms involved in cloud formation, while also fueling other forces that break clouds up. Global climate models that predict 2 degrees of warming in response to doubling CO2generally also see little or no change in cloudiness. Models that project a rise of 4 or more degrees forecast fewer clouds in the coming decades.

The climatologist Michael Mann, director of the Earth System Science Center at Pennsylvania State University, said that even 2 degrees of warming will cause “considerable loss of life and suffering.” He said it will kill coral reefs whose fish feed millions, while also elevating the risk of damaging floods, wildfires, droughts, heat waves, and hurricanes and causing “several feet of sea-level rise and threats to the world’s low-lying island nations and coastal cities.”

At the 4-degree end of the range, we would see not only “the destruction of the world’s coral reefs, massive loss of animal species, and catastrophic extreme weather events,” Mann said, but also “meters of sea-level rise that would challenge our capacity for adaptation. It would mean the end of human civilization in its current form.”

It is difficult to imagine what might happen if, a century or more from now, stratocumulus clouds were to suddenly disappear altogether, initiating something like an 8-degree jump on top of the warming that will already have occurred. “I hope we’ll never get there,” Tapio Schneider said in his Pasadena office last year.

The Simulated Sky

In the last decade, advances in supercomputing power and new observations of actual clouds have attracted dozens of researchers like Schneider to the problem of global warming’s X-factor. Researchers are now able to model cloud dynamics at high resolution, generating patches of simulated clouds that closely match real ones. This has allowed them to see what happens when they crank up the CO2.

First, physicists came to grips with high clouds — the icy, wispy ones like cirrus clouds that are miles high. By 2010, work by Mark Zelinka of Lawrence Livermore National Laboratory and others convincingly showed that as Earth warms, high clouds will move higher in the sky and also shift toward higher latitudes, where they won’t block as much direct sunlight as they do nearer the equator. This is expected to slightly exacerbate warming, and all global climate models have integrated this effect.

But vastly more important and more challenging than high clouds are the low, thick, turbulent ones — especially the stratocumulus variety. Bright-white sheets of stratocumulus cover a quarter of the ocean, reflecting 30 to 70 percent of the sunlight that would otherwise be absorbed by the dark waves below. Simulating stratocumulus clouds requires immense computing power because they contain turbulent eddies of all sizes.

Chris Bretherton, an atmospheric scientist and mathematician at the University of Washington, performed some of the first simulations of these clouds combined with idealized climate models in 2013 and 2014. He and his collaborators modeled a small patch of stratocumulus and found that as the sea surface below it warmed under the influence of CO2, the cloud became thinner. That work and other findings — such as NASA satellite data indicating that warmer years are less cloudy than colder years — began to suggest that the least sensitive global climate models, the ones predicting little change in cloud cover and only 2 degrees of warming, probably aren’t right.

Bretherton, whom Schneider calls “the smartest person we have in this area,” doesn’t only develop some of the best simulations of stratocumulus clouds; he and his team also fly through the actual clouds, dangling instruments from airplane wings to measure atmospheric conditions and bounce lasers off of cloud droplets.

In the Socrates mission last winter, Bretherton hopped on a government research plane and flew through stratocumulus clouds over the Southern Ocean between Tasmania and Antarctica. Global climate models tend to greatly underestimate the cloudiness of this region, and this makes the models relatively insensitive to possible changes in cloudiness.

Bretherton and his team set out to investigate why Southern Ocean clouds are so abundant. Their data indicate that the clouds consist primarily of supercooled water droplets rather than ice particles, as climate modelers had long assumed. Liquid-water droplets stick around longer than ice droplets (which are bigger and more likely to fall as rain), and this seems to be why the region is cloudier than global climate models predict. Adjusting the models to reflect the findings will make them more sensitive to cloud loss in this region as the planet heats up. This is one of several lines of evidence, Bretherton said, “that would favor the range of predictions that’s 3 to 5 degrees, not the 2- to 3-degree range.”

Schneider’s new simulation with Kaul and Pressel improved on Bretherton’s earlier work primarily by connecting what happens in a small patch of stratocumulus cloud to a simple model of the rest of Earth’s climate. This allowed them to investigate for the first time how these clouds not only respond to, but also affect, the global temperature, in a potential feedback loop.

Their simulation, which ran for 2 million core-hours on supercomputers in Switzerland and California, modeled a roughly 5-by-5-kilometer patch of stratocumulus cloud much like the clouds off the California coast. As the CO2 level ratchets up in the simulated sky and the sea surface heats up, the dynamics of the cloud evolve. The researchers found that the tipping point occurs, and stratocumulus clouds suddenly disappear, because of two dominant factors that work against their formation. First, when higher CO2 levels make Earth’s surface and sky hotter, the extra heat drives stronger turbulence inside the clouds. The turbulence mixes moist air near the top of the cloud, pushing it up and out through an important boundary layer that caps stratocumulus clouds, while drawing dry air in from above. Entrainment, as this is called, works to break up the cloud.

Secondly, as the greenhouse effect makes the upper atmosphere warmer and thus more humid, the cooling of the tops of stratocumulus clouds from above becomes less efficient. This cooling is essential, because it causes globs of cold, moist air at the top of the cloud to sink, making room for warm, moist air near Earth’s surface to rise into the cloud and become it. When cooling gets less effective, stratocumulus clouds grow thin.

Countervailing forces and effects eventually get overpowered; when the CO2 level reaches about 1,200 parts per million in the simulation — which could happen in 100 to 150 years, if emissions aren’t curbed — more entrainment and less cooling conspire to break up the stratocumulus cloud altogether.

To see how the loss of clouds would affect the global temperature, Schneider and colleagues inverted the approach of global climate models, simulating their cloud patch at high resolution and parameterizing the rest of the world outside that box. They found that, when the stratocumulus clouds disappeared in the simulation, the enormous amount of extra heat absorbed into the ocean increased its temperature and rate of evaporation.

Water vapor has a greenhouse effect much like CO2, so more water vapor in the sky means that more heat will be trapped at the planet’s surface. Extrapolated to the entire globe, the loss of low clouds and rise in water vapor leads to runaway warming — the dreaded 8-degree jump. After the climate has made this transition and water vapor saturates the air, ratcheting down the CO2 won’t bring the clouds back.

“There’s hysteresis,” Schneider said, where the state of the system depends on its history. “You need to reduce CO2 to concentrations around present day, even slightly below, before you form stratocumulus clouds again.”

Paleoclimatologists said this hysteresis might explain other puzzles about the paleoclimate record. During the Pliocene, 3 million years ago, the atmospheric CO2 level was 400 ppm, similar to today, but Earth was 4 degrees hotter. This might be because we were cooling down from a much warmer, perhaps largely cloudless period, and stratocumulus clouds hadn’t yet come back.

Past, Present and Future

Schneider emphasized an important caveat to the study, which will need to be addressed by future work: The simplified climate model he and his colleagues created assumed that global wind currents would stay as they are now. However, there is some evidence that these circulations might weaken in a way that would make stratocumulus clouds more robust, raising the threshold for their disappearance from 1,200 ppm to some higher level. Other changes could do the opposite, or the tipping point could vary by region.

To better “capture the heterogeneity” of the global system, Schneider said, researchers will need to use many simulations of cloud patches to calibrate a global climate model. “What I would love to do, and what I hope we’ll get a chance to do, is embed many, many of these [high-resolution] simulations in a global climate model, maybe tens of thousands, and then run a global climate simulation that interacts with” all of them, he said. Such a setup would enable a more precise prediction of the stratocumulus tipping point or points.

There’s a long way to go before we reach 1,200 parts per million, or thereabouts. Ultimate disaster can be averted if net carbon emissions can be reduced to zero — which doesn’t mean humans can’t release any carbon into the sky. We currently pump out 10 billion tons of it each year, and scientists estimate that Earth can absorb about 2 billion tons of it a year, in addition to what’s naturally emitted and absorbed. If fossil fuel emissions can be reduced to 2 billion tons annually through the expansion of solar, wind, nuclear and geothermal energy, changes in the agricultural sector, and the use of carbon-capture technology, anthropogenic global warming will slow to a halt.

What does Schneider think the future will bring? Sitting in his office with his laptop screen open to a mesmerizing simulation of roiling clouds, he said, “I am pretty — fairly — optimistic, simply because I think solar power has gotten so much cheaper. It’s not that far away from the cost curve for producing electricity from solar power crossing the fossil fuel cost curve. And once it crosses, there will be an exponential transformation of entire industries.”

Kerry Emanuel, the MIT climate scientist, noted that possible economic collapse caused by nearer-term effects of climate change might also curtail carbon emissions before the stratocumulus tipping point is reached.

But other unforeseen changes and climate tipping points could accelerate us toward the cliff. “I’m worried,” said Kennett, the pioneering paleoceanographer who discovered the PETM and unearthed evidence of many other tumultuous periods in Earth’s history. “Are you kidding? As far as I’m concerned, global warming is the major issue of our time.”

During the PETM, mammals, newly ascendant after the dinosaurs’ downfall, actually thrived. Their northward march led them to land bridges that allowed them to fan out across the globe, filling ecological niches and spreading south again as the planet reabsorbed the excess CO2 in the sky and cooled over 200,000 years. However, their story is hardly one we can hope to emulate. One difference, scientists say, is that Earth was much warmer then to begin with, so there were no ice caps to melt and accelerate the warming and sea-level rise.

“The other big difference,” said the climatologist Gavin Schmidt, director of the Goddard Institute, “is, we’re here, and we’re adapted to the climate we have. We built our cities all the way around the coasts; we’ve built our agricultural systems expecting the rain to be where it is and the dry areas to be where they are.” And national borders are where they are. “We’re not prepared for those things to shift,” he said.


This website is educational. Materials within it are being used in accord with the Fair Use doctrine, as defined by United States law.
§107. Limitations on Exclusive Rights: Fair Use. Notwithstanding the provisions of section 106, the fair use of a copyrighted work, including such use by reproduction in copies or phone records or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use, the factors to be considered shall include: the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes; the nature of the copyrighted work; the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and the effect of the use upon the potential market for or value of the copyrighted work. (added pub. l 94-553, Title I, 101, Oct 19, 1976, 90 Stat 2546)


NSTA Position Statement: The Teaching of Climate Science

NSTA National Science Teachers Association

The National Science Teachers Association (NSTA) acknowledges that decades of research and overwhelming scientific consensus indicate with increasing certainty that Earth’s climate is changing, largely due to human-induced increases in the concentrations of heat-absorbing gases (IPCC 2014; Melillo, Richmond, and Yohe 2014).

The scientific consensus on the occurrence, causes, and consequences of climate change is both broad and deep (Melillo, Richmond, and Yohe 2014). The nation’s leading scientific organizations support the core findings related to climate change, as do a broad range of government agencies, university and government research centers, educational organizations, and numerous international groups (NCSE 2017; U.S. Global Change Research Program 2017).

According to the National Academy of Sciences, “it is now more certain than ever, based on many lines of evidence, that humans are changing Earth’s climate” (NAS 2014). Scientific evidence advances our understanding of the challenges that climate change presents and of the need for people to prepare for and respond to its far-reaching implications (Melillo, Richmond, and Yohe 2014; Watts 2017).

The science of climate change is firmly rooted in decades of peer-reviewed scientific literature and is as sound and advanced as other established geosciences that have provided deep understandings in fields such as plate tectonics and planetary astronomy. As such, A Framework for K–12 Science Education (Framework) recommends that foundational climate change science concepts be included as part of a high-quality K–12 science education (NRC 2012).

Given the solid scientific foundation on which climate change science rests, any controversies regarding climate change and human-caused contributions to climate change that are based on social, economic, or political arguments—rather than scientific arguments—should not be part of a science curriculum.

NSTA recognizes that because of confusion and misinformation, many Americans do not think that the scientific basis for climate change is established and well-grounded (Leiserowitz 2005; van der Linden et al. 2015).

This belief, coupled with political efforts to actively promote the inclusion of non-scientific ideas in science classrooms (Plutzer et al. 2016), is negatively affecting science instruction in some schools. Active opposition to and the anticipation of opposition to climate change science from students, parents, other subject-area teachers, and/or school leadership is having a documented negative impact on science teachers in some states and local school districts (Plutzer et al. 2016).

Teachers are facing pressure to not only eliminate or de-emphasize climate change science, but also to introduce non-scientific ideas in science classrooms (NESTA 2011; Branch 2013; Branch, Rosenau, and Berbeco 2016).

This pressure sometimes takes the form of rhetorical tactics, such as “teach the controversy,” that are not based on science. Scientific explanations must be consistent with existing empirical evidence or stand up to empirical testing. Ideas based on political ideologies or pseudoscience that fail these empirical tests do not constitute science and should not be allowed to compromise the teaching of climate science. These tactics promote the teaching of non-scientific ideas that deliberately misinform students and increase confusion about climate science.

In conclusion, our knowledge of all the sciences, including climate science, grows and changes through the continual process of scientific exploration, investigation, and dialogue. While the details of scientific understandings about the Earth’s climate will undoubtedly evolve in the future, a large body of foundational knowledge exists regarding climate science that is agreed upon by the scientific community and should be included in science education at all levels. These understandings include the increase in global temperatures and the significant impact of human activities on these increases (U.S. Global Change Research Program 2009), as well as mitigation and resilience strategies that human societies may choose to adopt. Students in today’s classrooms will be the ones accelerating these decisions well underway in communities across the world.

NSTA confirms the solid scientific foundation on which climate change science rests and advocates for quality, evidence-based science to be taught in science classrooms in grades K–12 and higher education.


To ensure a high-quality K–12 science education constructed upon evidence-based science, including the science of climate change, NSTA recommends that teachers of science

  • recognize the cumulative weight of scientific evidence that indicates Earth’s climate is changing, largely due to human-induced increases in the concentration of heat-absorbing gases (IPCC 2014; Melillo, Richmond, and Yohe 2014);
  • emphasize to students that no scientific controversy exists regarding the basic facts of climate change and that any controversies are based on social, economic, or political arguments and are not science;
  • deliver instruction using evidence-based science, including climate change, human impacts on natural systems, human sustainability, and engineering design, as recommended by the Framework for K–12 Science Education (Framework);
  • expand the instruction of climate change science across the K–12 span, consistent with learning progressions offered in the Framework;
  • advocate for integrating climate and climate change science across the K–12 curriculum beyond STEM (science, technology, engineering, and mathematics) classes;
  • teach climate change as any other established field of science and reject pressures to eliminate or de-emphasize climate-based science concepts in science instruction;
  • recognize that scientific argumentation is not the same as arguing beliefs and opinions. It requires the use of evidence-based scientific explanations to defend arguments and critically evaluate the claims of others;
  • plan instruction on the premise that debates and false-equivalence arguments are not demonstrably effective science teaching strategies;
  • help students learn how to use scientific evidence to evaluate claims made by others, including those from media sources that may be politically or socially biased;
  • provide students with the historical basis in science that recognizes the relationship between heat-absorbing greenhouse gases—especially those that are human-induced—and the amount of energy in the atmosphere;
  • highlight for students the datasets from which scientific consensus models are built and describe how they have been tested and refined;
  • recognize that attempts to use large-scale climate intervention to halt or reverse rapid climate change are well beyond simple solutions and will likely result in both intended and unintended consequences in the Earth system (NRC 2015; USGCRP 2017);
  • analyze different climate change mitigation strategies with students, including those that reduce carbon emissions as well as those aimed at building resilience to the effects of global climate change;
  • seek out resources and professional learning opportunities to better understand climate science and explore effective strategies for teaching climate science accurately while acknowledging social or political controversy; and
  • analyze future climate change scenarios and their relationships to societal decisions regarding energy-source and land-use choices.

Necessary Support Structures

To support the work of teachers of science, NSTA recommends that school administrators, school boards, and school and district leaders

  • ensure the use of evidence-based scientific information when addressing climate change and climate science in all parts of the school curriculum, such as social studies, mathematics, and reading;
  • provide teachers of science with ongoing professional learning opportunities to strengthen their content knowledge, enhance their teaching of scientific practices, and help them develop confidence to address socially controversial topics in the classroom;
  • support teachers as they review, adopt, and implement evidence-based science curricula and curricular materials that accurately represent the occurrence of, evidence for, and responses to climate change;
  • ensure teachers have adequate time, guidance, and resources to learn about climate science and have continued access to these resources;
  • resist pressures to promote non-scientific views that seek to deemphasize or eliminate the scientific study of climate change, or to misrepresent the scientific evidence for climate change; and
  • provide full support to teachers in the event of community-based conflict.

To support the teaching of climate change in K–12 school science, NSTA recommends that state and district policy makers

  • ensure that licensure and preparation standards for all teachers of science include science practices and climate change science content;
  • ensure that instructional materials considered for adoption are based on both recognized practices and contemporary, scientifically accurate data;
  • preserve the quality of science education by rejecting censorship, pseudoscience, logical fallacies, faulty scholarship, narrow political agendas, or unconstitutional mandates; and
  • understand that demand is increasing for a workforce that is knowledgeable about and capable of addressing climate change mitigation and building resilience to the effects of global climate change.

To support the teaching of climate change in K–12 school science, NSTA recommends that parents and other members of the community and media

  • seek the expertise of science educators on science topics, including climate change science;
  • augment the work of science teachers by supporting student learning of science at home, including the science of climate change;
  • help students understand the contributions that STEM professionals, policy makers, and educators can make to mitigate the effects of climate change and how they can make decisions that contribute to desired outcomes; and
  • clarify that societal controversies surrounding climate change are not scientific in nature, but are social, political, and economic.

To support the teaching of climate change in K–12 school science, NSTA recommends that higher education professors and administrators

  • design curricula that incorporate climate change science into science and general education coursework, and that these materials meet social, economic, mathematical, and literary general education goals;
  • provide teacher-education students with science content and pedagogy that meets the Framework‘s expectations for the grade band(s) they will teach; and
  • recognize that a solid foundation in Earth system science should be a consideration in student admissions decisions.

Adopted by the NSTA Board of Directors, September 2018

If we assume global warming is a hoax, what should we expect to see

This analysis is by Phil Plait, Mar 9, 2017

Global warming GIF

I will ask you to indulge me for a moment in a thought experiment. It’s not hard, and it leads to a startlingly simple yet powerful conclusion, one I think you may find both important and terribly useful.

Still, it starts with a big ask, so forgive me. And that is: Let’s make an assumption, one you’ve heard many times before. Let’s say that global warming is a hoax.

I know, I know. But go with this, here. So, yes, let’s say that climate change deniers —people like House Science, Space, and Technology Committee chairman Lamar Smith, Senator James Inhofe, and even Donald Trump himself— are right. Whatever the reasons (Chinese hoax, climatologist cabal clamoring colossal cash, carbon dioxide isn’t a powerful greenhouse gas, or just a liberal conspiracy), let’s say that the Earth is not warming up.

In that case, the temperatures we see today on average should be much like the ones we saw, say, 20 years ago. Or 50. Sure, you’d see fluctuations. In a given spot on a given day the temperature in 1968 might have been a degree warmer than it was in 1974, or three degrees cooler than in 2010. But what you’d expect is that over time, a graph showing the temperature would be pretty much flat, with lots of short-term spikes up and down.

Now, statistically speaking, you expect some records to be broken every now and again. Over time, every few years for a given day you’d get a record high, and every few years a record low. The details will change from place to place and time to time, but again, if the average temperature trend is flat, unchanging, then you would expect to see just as many record cold days as record warm days. There might be small deviations, like, say, a handful of more cool than warm days, but the difference would be very small depending on how many days you look at.

It’s like flipping a coin. On average, you should get a 50/50 split between heads and tails. But if you flip it 10 times, say, you wouldn’t be shocked to see seven heads and three tails. But if you flip it a thousand times, you’d really expect to see a very even split. Seeing 700 heads and 300 tails would be truly extraordinary.

So, if we remind ourselves of our basic assumption —global warming isn’t real— then we expect there to be as many record high days as there are record lows. Simple statistics.

So, what do we see?

Guy Walton, a meteorologist in Georgia, took a look at the data from the NOAA’s National Centers for Environmental Information. Whenever a weather station in the US breaks a record, high or low, it’s catalogued (Walton has more info on this at the link above). He found something astonishing: For February 2017, the number of record highs across the US recorded was 6,201.

The number of record lows? 128.

That’s a ratio of over 48:1. In just one month.

Again, if temperatures were flat over time, and record highs and lows were random fluctuations, you’d expect a ratio much closer to 1:1. In other words, out of 6329 records set in total, you’d expect there to be about 3165 record highs, and 3165 record lows.

For fans of statistics, with a total of 6329 records broken, one standard deviation is the square root of that, or about 80. So, sure, something like 3265 highs and 3064 lows wouldn’t be too unusual. If you start to see more of an imbalance than that, it would be weird.

Seeing 6201 record highs to 128 lows is very, very, very weird. Like, zero chance of that happening by accident.

Now, Phil, I can hear you thinking, that’s just for the US (2% of the planet) over one month. And you’ve told us before that weather isn’t climate; weather is what you expect now, climate is what you expect over long periods of time. So, maybe this is a fluke?

Walton notes that, if you look at records in the US going back to the 1920s, the six highest ratios of record highs to lows all occur since the 1990s. Huh.

And making this more global, a pair of Australian scientists looked at their country’s data, and found that their ratios were about even…until the 1960s. After that, highs always outnumber lows. From 2000-2014, record highs outnumbered lows there by 12:1.

The University Corporation for Atmospheric Research collated data from 1800 stations across the US and binned the data by decade — by decade, which is a huge sample; any deviation from a 1:1 ratio would be extraordinary over that timescale.

They found this:

Record Highs and Lows Global warming

This graphic shows the ratio of record daily highs to record daily lows observed at about 1,800 weather stations in the 48 contiguous United States from January 1950 through September 2009. Each bar shows the proportion of record highs (red) to record lows (blue) for each decade. The 1960s and 1970s saw slightly more record daily lows than highs, but in the last 30 years record highs have increasingly predominated, with the ratio now about two-to-one for the 48 states as a whole. (©UCAR, graphic by Mike Shibao.)


Source of the above image: RECORD HIGH TEMPERATURES FAR OUTPACE RECORD LOWS ACROSS U.S. The National Center for Atmospheric Research/UCAR, Nov 12, 2009

We are seeing far more record high temperatures than record lows in the US… and in other countries, too. Credit: UCAR

Huh. Not only are there more record highs than lows, the ratio between the two is getting higher with time.

So, looking back at our initial assumption — the Earth isn’t warming, and temperatures are flat— there’s a conclusion these data are screaming at us: That assumption is completely and utterly wrong.

And of course, all the evidence backs this up. All of it. Earth’s temperature is increasing. That’s because of the 40 billion tons of extra carbon dioxide humans put into the atmosphere every year (the amount we will see this year, expected to top 410 parts per million, has never been seen before in history as long as humans have walked the Earth). This CO2 allows sunlight to warm the Earth, but prevents all of it from escaping so that a little bit of extra heat remains behind, and that’s warming our planet.

Over time, we’re getting hotter. 2014 was a record hot year, beaten by 2015, itself beaten by 2016. In fact, 15 of the 16 hottest years ever recorded have been from 2001 – 2016. That’s exactly what you’d expect if we were getting warmer, and that means our initial assumption of hoaxery was dead wrong.

The science on this is so basic, the evidence of this so overwhelming, that “not a single national science academy disputes or denies the scientific consensus around human-caused climate change”, and also the overwhelming majority of scientists who study climate do, too.

Maybe you should listen to them, and not politicians who seem ideologically opposed to the science.

Or, you could flip a coin. But if it comes up science dozens of times more often than anti-science, well —and forgive me if I sound like a broken record— the conclusion is obvious.


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Boston and sea levels

How can we protect Boston from rising sea levels? Various proposals

I. Build a dike around the harbor

Metro Boston Dikelands: A 14 mile dike around the harbor.

A 14-mile dike could protect Greater Boston from sea level rise. The barrier would run from Cohasset to Swampscott

…The metropolitan Boston estuary is uniquely different from many others around the nation. It is protected on its flanks by the shoulder highlands of Swampscott and Cohasset. The Metro Boston DikeLANDS proposal takes advantage of the estuary’s unique geological characteristics.

Metro Boston Dikelands Dike

We propose building a 14-mile dike barrier between the shoulder highlands of Cohasset and Swampscott. The dike would be located some eight miles out from Deer Island, complete with residential and commercial developments, windmills, solar collector farms, and recreational areas.

A simple dike barrier with a 200-foot-wide top and reaching 120 feet from seafloor to storm-surge top would require some 246 million cubic yards of material. Bi-directional locks could provide access for all crafts, protecting Boston’s commercial activity and its waterfront integrity.

The new dike system will prevent storm tides from inundating the entire metropolitan estuary while allowing rivers to discharge their water into a harbor reservoir capable of holding more than 10 billion gallons of river-fed water… By lowering the reservoir level to half the current tidal range, the cherished Boston Harbor Islands and their recreational potential would be protected.

At a cost of $100 per cubic yard, with two bi-directional shipping locks of $500 million each (plus soft and contingency costs), this macro-engineering and macro-economic project would probably cost between $30 billion and $50 billion. The 200-foot wide top of the 14-mile stretch would create 68 acres of new dike lands, which in turn would need to be supported by a complete infrastructure system of water, sewer, electricity, and transportation …

The project could help pay for itself if the newly-created, flat-top area of the dike, amounting to some 68 acres, was sold as waterfront property at between $3 and $7 million per acre. That would raise between $100 billion and $400 billion (after return on invested capital)

Source: 14-mile dike could protect Greater Boston from sea level rise, Commonwealth Magazine, Jan 2018, Peter Papesch, Franziska Amacher and A. Vernon Woodworth, members of the Boston Society of Architects

Plan details Metro-Boston-Dike-Barrier.pdf


II. Climate Ready Boston: Planning three possible harbor dikes

The team, led by Paul Kirshen, a professor of climate adaptation at UMass’ School for the Environment, is weighing three harbor barrier configurations. The barrier study was recommended in the city’s Climate Ready Boston report.

The smallest would connect Logan Airport in East Boston with Castle Island in South Boston, protecting the city’s inner harbor and downtown from tidal flooding.

The medium-sized solution is a barrier from Deer Island, in the harbor, to Quincy, which would wall off all of Boston’s neighborhoods.

The largest of the proposed harbor barriers would protect not just Boston, but also Weymouth, Hingham, Quincy and Hull.

Boston Harbor Dike barrier proposals


III. Resilient Boston Harbor

Learn about our climate-ready vision to enhance Boston’s waterfront. We want to protect Boston’s neighborhoods from sea level rise and flooding due to climate change.

Adapted infrastructure: Elevated roadways, strengthened seawalls, and flood barriers.

Protective Waterfront parks: Waterfronts include living shorelines, beaches, elevated parks, and access to water transportation.

Boston protective waterfront parks sea level

Elevated harborwalks: By improving elevation and access, we can use our harborwalk system to protect against floods.

Boston sea level elevated Harborwalks


IV. Make parts of Boston a city of canals

From the Urban Land Institute of Boston/New England’s “The Urban Implications of Living with Water”

Boston: The urban implications of living with water. Urban land institute

With the future unclear about exactly when the full impacts of sea level rise will occur, designing now for flexibility and the ability to adapt becomes critical. For example, with major street sections to be rebuilt, the typical 60 or 75 foot cross-section can be planned to be able to change when conditions warrant.

The goal is to provide for current urban linkages across the district without limiting the ability to accommodate future needs. Such needs could take the form of green infrastructure or surface channels to move water safely and quickly back to the ocean.

Build canals through Boston’s Back Bay

Canals in Boston Back Bay

A street view of what this could look like

Boston canal Michael Wang, Arlen Stawasz, and Dennis Carlberg

Report offers ideas for a Boston beset by rising seas Envisions canals, fortifications. Boston Globe, 2014

V. As done in the past, raise the level of parts of Boston

Can lessons from Boston’s landfill, 250 years ago, help Boston deal with sea level rise today?

Alex Wilson, in A Bold Idea for Addressing Sea Level Rise, writes

… I was struck by the realization that 250 years ago Boston was an island, connected by just a single land-bridge …there must have been a fairly massive effort to build the current land base of Boston. Might strategic land-building be an option for us as we are forced over the next century to address sea level rise as global warming melts the huge ice masses in Greenland and Antarctica?

…Rising seas are making life increasingly difficult in low-lying portions of dozens of U.S. cities today. The journal Nature Climate Change published a paper projecting the number of people in coastal regions of the U.S. who would be affected by sea level rise of 0.9 meters (3 feet) and 1.8 meters (5 feet). Unlike previous assessments of impact, this study considered not only current populations, but also projected population growth in these regions.

Sea level rise impact by state
Populations in U.S. states that would be affected by 0.9 and 1.8 meter sea level rise.

Source: Nature Climate Change paper, “Millions Projected To Be At Risk From Sea-Level Rise in the Continental United States,” by Matthew Hauer, et. al., published online March 14, 2016.

By the year 2100, U.S. residents affected by 0.9 m and 1.8 m sea level rise would total 1.46 million and 3.85 million, respectively. Factoring in projected population growth in these regions, however, the number of people affected increases to 4.31 million and 13.1 million, respectively.

Can lessons from Boston’s landfill, 250 years ago, help with sea level rise today?

The comprehensive book, Gaining Ground: A History of Landmaking in Boston, by Nancy S. Seasholes, describes more than three centuries of effort to the Boston area to create new land and raise the elevation of existing land.

Beginning fairly early in Boston’s history—certainly by the 1700s—there was a massive effort to fill in the tidal flats around Boston. These efforts ultimately created some 5,250 acres of new land in Boston, East Boston, and Charlestown. In other areas, the land was significantly raised with fill. The original peninsula of Boston, known as Shawmut by the Native Americans, was just 487 acres. Today, merged with surrounding land, it is many times that size.

…Boston’s well-known Back Bay region was originally the back bay of the Charles River—an extensive estuary on the western side of the Shawmut Peninsula. The Fenway and Fenway Park (the Boston Red Sox’s home stadium) get their names from the fens or bogs in the area. It was only after extensive filling that building here was possible.

Logan Airport was open water in the 1930s. Today it is part of the extensive new land in East Boston.

I haven’t seen estimates of the amount of fill been used in Greater Boston over the last three centuries. If one assumes an average fill of six feet over the 5,250 acres of made land, that would total roughly 1.4 billion cubic feet or 50 million cubic yards.

I was particularly intrigued to learn in Gaining Ground that not only was new land made on the tidal flats of Boston, but in some places the elevation of existing land was raised. In the Church Street and Suffolk Street Districts (new Bay Village and Castle Square), sewage back-up was a problem in the mid-1800s, because there wasn’t enough pitch to the sewers (which no doubt dumped into the Bay).

The solution was to elevate the land and the buildings that were located there. In the 1860s, the City decided to raise the grade of the entire District. They would fill basements and abandon them, elevate buildings on cribbing and build new foundations beneath them.

On Church Street, starting in July 1868, the City hired contractors to bring in more than 150,000 cubic yards of fill and elevate 296 brick buildings by as much as 14 feet and 56 wooden buildings by as much as 17 feet. Remarkably (by today’s standards), this work was virtually completed by October 1869—ahead of schedule and under budget.

Church Street elevating 1868 Boston_Public_Library

A similar project was carried out in the Suffolk Street District starting in July 1870 and being completed by the end of 1872. Nearly 250,000 yards of fill were brought in, and 600 buildings were elevated—also under budget.

Boston isn’t alone in having seen extensive landmaking over the centuries. In Manhattan, several thousand acres of land were created using fill, and more than 3,000 acres were created in Chicago. But nowhere in the U.S. has the landmaking been as extensive as in Boston.

What this suggests about our long-term response to rising sea levels is that we shouldn’t rule out the idea of raising the grade in our most important cities. I was astounded to learn just how significant the earthmoving was centuries ago; with today’s equipment and engineering prowess, one can imagine raising a low-lying city by tens of feet.

Of course, there would be huge challenges and tremendous costs with such an initiative, not to mention environmental risks. Our buildings are bigger than those in Boston were in the 1860s; they are closer together and more complex. Our infrastructure—streets and highways, bridges, sewers, power grids, pipelines—are tremendously complex. And, we’re much more conscious of ecological damage today than we were 150 years ago.

But consider the alternative. Are we ready to abandon cities like Boston, New York, Philadelphia, and Charlestown? It could well be easier to raise a city than to move it. And we will have to figure this out before the end of this century. I don’t know if raising the elevation of our low-lying cities will make sense, but I think we should begin that discussion.

We can start by looking at past experience, and Gaining Ground provides a good starting point in doing so. In some cases, it may be possible to fill in basements, compacting the fill to equalize the pressure on the outside of those walls, and turn first floors into basements—essentially eliminating an occupied floor of a building.

In other cases, entire buildings may have to be elevated and new foundations built on compacted fill 15 or 20 feet higher. Streets would have to be covered and rebuilt on fill. Very challenging will be the need for such modifications to be coordinated on a neighborhood-by-neighborhood basis. You can’t raise one building 20 feet and not do anything with the building next door.

This would be an extraordinarily complex process in terms of phasing, implementation, and environmental protection. But it’s time to take sea level rise seriously and begin looking at our options. Raising land mass may be one such option.

Source: Alex Wilson, Resilientdesign.org, A bold idea for addressing sea level rise,  Mar 28, 2016


Boston underwater: How the rising sea levels will affect the city

Underwater: How the rising sea levels will affect various cities

Massachusetts Sea Level Rise and Coastal Flooding Viewer

http://climateactiontool.org: Sea level rise Massachusetts

– and Intro: Massachusetts Sea Level Rise and Coastal Flooding Viewer

Sea Level Rise Viewer NOAA Office for Coastal Management

Surging Seas RISK ZONE MAP

Explore the spatial data used in Climate Ready Boston – This app allows you to learn more about the data layers used in the Climate Ready Boston recommendations for protecting our City from a changing climate, and helps you better understand how projections are influencing resiliency solutions. Read the introduction to this interactive tool.


How Boston’s Preparing For Rising Sea Levels By Anaridis Rodriguez, WBZ-TV

Climate Ready Boston is an initiative to develop resilient solutions to prepare our City for climate change.

Greenovate Boston: Carbon Free Boston is an initiative to prepare the City to go carbon neutral by 2050.

Sasaki : Sea Change Boston. Designing in the Face of Climate Change– Sasaki is a global design firm specializing in architecture, planning, urban design, landscape architecture.

Wall to protect Boston from flooding would cost up to $12 billion to build. MassLive.com

A much-anticipated new report on how best to protect the Seaport District and other Boston neighborhoods from the effects of climate change finds that the cost to build a massive, multibillion-dollar wall in Boston Harbor is not worth the benefits.

Instead, it finds that the city of Boston and other coastal cities and towns should focus on more localized projects to counteract the flooding and higher sea levels wrought by global warming, said the report… “Right now, it doesn’t make sense for the city to consider any kind of harborwide barrier system,” said the report’s lead investigator, Paul Kirshen of UMass Boston’s Sustainable Solutions Lab. “It doesn’t make sense for decades, if not ever.” The report was sponsored by the Boston Green Ribbon Commission, a coalition of business and civic leaders formed more than a decade ago to help the city address climate change

… Either barrier could cut down on coastal flooding without significantly disrupting shipping or the environment, according to the report. But “shore-based” solutions, as the researchers call them, can provide the same level of protection at a cost of just $1 billion to $2 billion, with additional benefits to boot, Kershen told reporters Tuesday. Shore-based systems could include flood walls on a much smaller scale than a harborwide barrier, changes to zoning laws, and the raising of land using berms, among other projects.

Data articles

Boston Sea Level data

Sea Level Rise has Accelerated

Learning Standards

2016 Massachusetts Science and Technology/Engineering Curriculum Framework

HS-ESS2-6. Use a model to describe cycling of carbon through the ocean, atmosphere, soil, and biosphere and how increases in carbon dioxide concentrations due to human activity have resulted in atmospheric and climate changes.

HS-ESS3-1. Construct an explanation based on evidence for how the availability of key natural resources and changes due to variations in climate have influenced human activity.

HS-LS2-7. Analyze direct and indirect effects of human activities on biodiversity and ecosystem health, specifically habitat fragmentation, introduction of non-native or invasive species, overharvesting, pollution, and climate change. Evaluate and refine a solution for reducing the impacts of human activities on biodiversity and ecosystem health.*

High School Technology/Engineering

HS-ETS1-1. Analyze a major global challenge to specify a design problem that can be improved. Determine necessary qualitative and quantitative criteria and constraints for
solutions, including any requirements set by society.*

HS-ETS1-2. Break a complex real-world problem into smaller, more manageable problems that each can be solved using scientific and engineering principles.*

HS-ETS1-3. Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, aesthetics, and maintenance, as well as social, cultural, and environmental impacts.*

Protecting cities from rising sea levels

Protecting cities from rising sea levels

from “Can New York Be Saved in the Era of Global Warming?” by Jeff Goodell, Rolling Stone, July 2016.

Hurricane Sandy, which hit New York in October 2012, flooding more than 88,000 buildings in the city and killing 44 people, was a transformative event. It did not just reveal how vulnerable New York is to a powerful storm, but it also gave a preview of what the city faces over the next century, when sea levels are projected to rise five, six, seven feet or more, causing Sandy-like flooding (or much worse) to occur with increasing frequency.

Hurricane Sandy flooding East Village NYC

Credit – Jamal Countess/Redux

Zarrilli turns away from the river, and we walk toward the park that separates it from the Lower East Side. “One of our goals is not just to protect the city, but to improve it,” Zarrilli explains. Next year, if all goes well, the city will break ground on what’s called the East Side Coastal Resiliency Project, an undulating 10-foot-high steel-and-concrete-reinforced berm that will run about two miles along the riverfront. It’s the first part of a bigger barrier system, known informally as “the Big U,” that someday may loop around the entire bottom of Manhattan… there are plans in the works to build other walls and barriers in the Rockaways and on Staten Island, as well as in Hoboken, New Jersey, across the Hudson River. …

…wall-building is politically fraught: You can’t wall off the city’s entire 520-mile coastline, so how do you decide who gets to live behind the wall and who doesn’t? “You have to start somewhere,” Zarrilli says, “so you begin in the places where you get the maximum benefit for the most people.”

In Zarrilli’s view, there is no time to waste. By 2030 or so, the water in New York Harbor could be a foot higher than it is today. That may not sound like much, but New York does not have to become Atlantis to be incapacitated. Even with a foot or two of sea-level rise, streets will become impassable at high tide, snarling traffic. …

Then the big storm will come… if you add a foot or two of sea-level rise to a 14-foot storm tide, you have serious trouble. …Water will flow over the aging sea walls at Battery Park and onto the West Side, pouring into the streets, into basements, into cars, into electrical circuits, finding its way into the subway tunnels. New Yorkers will learn that even after the region spent $60 billion on rebuilding efforts after Sandy, the city’s infrastructure is still hugely vulnerable.

… New York’s Achilles’ heel is the subways, which are vulnerable to saltwater, which is highly corrosive to electrical circuits, as well as to the concrete in the tunnels. In theory, the subway system can be restructured to keep seawater out, but at some point, the cost gets prohibitive. … the Metropolitan Transportation Authority, which operates the New York subways, had to spend $530 million upgrading the South Ferry station in Lower Manhattan after it was heavily damaged on 9/11. After Sandy turned the station into a fish tank, the MTA had to close it for months and spend another $600 million to fix it. The MTA has now installed retractable barriers to stop seawater from flooding the station in the next big storm, but the subway system remains vulnerable to rising seas. “We’re not thinking systemically about climate change,” says Michael Gerrard, director of the Center for Climate Change Law at Columbia Law School. “We’re focused on Sandy, and Sandy isn’t the worst thing that could happen.”

In the end, there is only one real solution for sea-level rise: moving to higher ground.

In the near future, one of the main drivers of what policy wonks call “managed retreat” is likely to be the rising costs of flood insurance, which is provided to most property owners through National Flood Insurance Protection, an outdated, mismanaged federal program that subsidizes insurance rates for homeowners and businesses in high-risk areas (commercial insurers bailed out of the flood-insurance market decades ago).

Under NFIP, few people who live in flood-prone areas pay the actual cost of the risk. In addition, grandfather clauses in the program often allow homeowners to rebuild in areas that are doomed to flood again very soon. Attempts by Congress to reform the program have failed miserably, and it’s now $23 billion in debt. Eventually, increasing property losses will force reform and insurance rates will go up and up. “When people have to pay more and own more of the risk themselves, their decisions about where they live will change,” says Alex Kaplan, a senior vice president at Swiss Re, a global reinsurance company.

New York state is already experimenting with voluntary buyouts in high-risk areas. The logic is simple: In the long run, it’s cheaper simply to buy people out of their homes than to keep paying for them to be rebuilt after storms (it also moves people out of harm’s way).

Of course, it would cost hundreds of billions of dollars to buy out residents and businesses in Lower Manhattan. Instead, some urban planners have discussed offering tax breaks and other financial goodies to encourage residents and businesses to relocate to higher ground. Could parts of Lower Manhattan ever be de-populated and returned to nature? “Buildings were built,” says Kate Orff, director of the urban-planning program at Columbia University’s Graduate School of Architecture, Planning and Preservation. “They can also be unbuilt.” More likely, the walls will go up, getting higher and higher as the seas rise.

The above info is from https://www.rollingstone.com/politics/news/can-new-york-be-saved-in-the-era-of-global-warming-20160705#ixzz4Da26LKLM


Protecting Staten Island, New York City

Topic: Staten Island Multi-Use Elevated Promenade

This text from the article “A 5.3-Mile “Elevated Promenade” On Staten Island Will Break Ground This Year” by Bianca Bahmondes, Secret NYC, 2/25/2019

It was recently announced that the 5.3-mile proposed seawall in Staten Island will officially begin construction since federal funding has now been secured. The U.S. Army Corps for Engineers (USACE) will be giving $400 million to the project, which is formally known as the Staten Island Multi-Use Elevated Promenade. This new promenade has been in the works since 2015 and is intended to help protect the island from sea-level rising, storm surges, and super storms in the future.

It will be build along the island’s eastern coast from Fort Wadsworth to Great Kills. The promenade will rise about 20 feet above sea level and feature a series of interconnected leaves, berms, and seawalls that are designed to withstand a 300-year storm.

In the announcing statement Governor Cuomo said: “This innovative project will protect Staten Islanders from future devastating storms, enhance access to the shore, create thriving wetlands and bring peace of mind to the diverse communities that live along the coastline. [This] agreement allows New York to move forward with this critical resiliency measure, which will ensure vulnerable communities have the resources they need to build back stronger after the devastation of Hurricane Sandy and better prepare for the next 100-year storm.”

Images from https://www.governor.ny.gov/sites/governor.ny.gov/files/atoms/files/Visualization.pdf

Staten Island Multi-Use Elevated Promenade 1

Staten Island Multi-Use Elevated Promenade 2


Further reading


Learning Standards

2016 Massachusetts Science and Technology/Engineering Curriculum Framework

HS-ESS2-6. Use a model to describe cycling of carbon through the ocean, atmosphere, soil, and biosphere and how increases in carbon dioxide concentrations due to human activity have resulted in atmospheric and climate changes.

HS-ESS3-1. Construct an explanation based on evidence for how the availability of key natural resources and changes due to variations in climate have influenced human activity.

HS-LS2-7. Analyze direct and indirect effects of human activities on biodiversity and ecosystem health, specifically habitat fragmentation, introduction of non-native or invasive species, overharvesting, pollution, and climate change. Evaluate and refine a solution for reducing the impacts of human activities on biodiversity and ecosystem health.*

High School Technology/Engineering

HS-ETS1-1. Analyze a major global challenge to specify a design problem that can be improved. Determine necessary qualitative and quantitative criteria and constraints for
solutions, including any requirements set by society.*

HS-ETS1-2. Break a complex real-world problem into smaller, more manageable problems that each can be solved using scientific and engineering principles.*

HS-ETS1-3. Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, aesthetics, and maintenance, as well as social, cultural, and environmental impacts.*

XKCD: Although the climate has always changed, that is no comfort

Yes, the climate has always changed. This shows why that’s no comfort.

By Brad Plumer, vox.com Jan 13, 2017

Randall Munroe, the author of the webcomic XKCD, has a habit of making wonderfully lucid infographics on otherwise difficult scientific topics. Everyone should check his take on global warming. It’s a stunning graphic showing Earth’s recent climate history. Take some time with it. Stroll through the events like the domestication of dogs and the construction of Stonehenge. And then ponder the upshot here.

There’s a common line among climate skeptics that “[t]he climate has always changed, so why worry if it’s changing now?” The first half of that sentence is undeniably true. Due to orbital wobbles, volcanic activity, rock weathering, and changes in solar activity, the Earth’s temperature has waxed and waned over the past 4.5 billion years. During the Paleocene it was so warm that crocodiles swam above the Arctic Circle. And 20,000 years ago it was cold enough that multi-kilometer-thick glaciers covered Montreal.

But Munroe’s comic below hits at the “why worry.” What’s most relevant to us humans, living in the present day, is that the climate has been remarkably stable for the past 12,000 years. That period encompasses all of human civilization — from the pyramids to the Industrial Revolution to Facebook and beyond. We’ve benefited greatly from that stability. It’s allowed us to build farms and coastal cities and thrive without worrying about overly wild fluctuations in the climate.

And now we’re losing that stable climate. Thanks to the burning of fossil fuels and land use changes, the Earth is heating up at the fastest rate in millions of years, a pace that could prove difficult to adapt to. Sea level rise, heat waves, droughts, and floods threaten to make many of our habitats and infrastructure obsolete. Given that, it’s hardly a comfort to know that things were much, much hotter when dinosaurs roamed the Earth.

XKCD A timeline of Earth's average history

Image by XKCD (Randall Munroe)


Global warming and greenhouse gases

Global warming has not stopped

Global warming: Pause in the rate of temp rise

Global warming Industry knew of climate change

Global warming: Adjusted data sets are a normal part of science

Climate skeptics are not like Galileo.

Yes, the climate has always changed. But this shows why that’s no comfort: XKCD infographic