The Intergovernmental Panel on Climate Change (IPCC) has released their summary report on the climate emergency, which warns that our climate is now changing rapidly almost everywhere and immediate & massive action is necessary. The press release starts:
Scientists are observing changes in the Earth’s climate in every region and across the whole climate system, according to the latest Intergovernmental Panel on Climate Change (IPCC) Report, released today. Many of the changes observed in the climate are unprecedented in thousands, if not hundreds of thousands of years, and some of the changes already set in motion — such as continued sea level rise — are irreversible over hundreds to thousands of years.
However, strong and sustained reductions in emissions of carbon dioxide (CO2) and other greenhouse gases would limit climate change. While benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilize, according to the IPCC Working Group I report, Climate Change 2021: the Physical Science Basis, approved on Friday by 195 member governments of the IPCC, through a virtual approval session that was held over two weeks starting on July 26.
This is a huge deal — all 195 member governments had to approve the findings and language in this report and the report is not ambiguous. From Eric Holthaus:
The report’s main takeaway, put in a single sentence directly quoted from the report’s press release: “Unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will be beyond reach.”
That means “immediate, rapid, large-scale” change is what we MUST demand — there’s a vastly limited future for all of us if it doesn’t happen right away.
The most striking part of the report to me is its of use the word “rapid” prominently, which to me is a major change from past reports.
The era of rapid climate change has begun. Both a rapid escalation of consequences, and a rapid escalation of solutions. Time has run out for anything but radical change.
To me, the report is equal parts depressing and galvanizing.
It will take several years, even in the best possible scenario, to see the positive effects of rapidly reductions in emissions. But that’s not so different from every other worthwhile investment we make — from going to school, to going to therapy, to building bike lanes, to forming communities of mutual aid. Every worthwhile thing takes time. And, if we believe this report, the next 20-30 years is the most important time of our whole lives.
In this video, Joss Fong and her team at Vox look at the cost of air travel to our environment, investigate electric airplanes, and consider whether it’s wrong to fly in the age of climate crisis.
Climate change implicates us all in a planet-sized injustice. If I fly, if I drive, if I heat or cool my home, if I buy stuff, if I eat stuff, all of this now has a cost that I’m not paying.
One of the ways that climatologists know that the dramatically increasing amount of atmospheric carbon dioxide (and corresponding temperature increase) is caused by human activity is by measuring changing land use and how much fossil fuel has been burned over the last few hundred years. From a 2004 RealClimate article:
One way that we know that human activities are responsible for the increased CO2 is simply by looking at historical records of human activities. Since the industrial revolution, we have been burning fossil fuels and clearing and burning forested land at an unprecedented rate, and these processes convert organic carbon into CO2. Careful accounting of the amount of fossil fuel that has been extracted and combusted, and how much land clearing has occurred, shows that we have produced far more CO2 than now remains in the atmosphere. The roughly 500 billion metric tons of carbon we have produced is enough to have raised the atmospheric concentration of CO2 to nearly 500 ppm. The concentrations have not reached that level because the ocean and the terrestrial biosphere have the capacity to absorb some of the CO2 we produce. However, it is the fact that we produce CO2 faster than the ocean and biosphere can absorb it that explains the observed increase.
That was back when the CO2 concentration was ~380 parts per million…it’s now ~407 ppm. That is pretty convincing evidence all by itself…the inputs match the outputs.
But there is also extremely compelling corroborating evidence that has to do with what kind of carbon is being released into the atmosphere — the smoking gun of anthropogenic climate change, if you will. For several hundred years before the start of the 19th century, the CO2 in the atmosphere contained a more-or-less consistent ratio of two carbon isotopes: carbon-12 and carbon-13 (which contains one more neutron than carbon-12 and is therefore heavier). Plants prefer consuming the lighter carbon-12 over carbon-13 and since fossil fuels are ultimately made from decayed plants, when you burn them, they disproportionately produce carbon-12 (when compared to atmospheric CO2).
So if you’re burning a bunch of oil and coal, you’d expect to see carbon-12 levels in the atmosphere go up…and that’s exactly what scientists have found. If you graph the amount of carbon-12 present in the atmosphere over time, you can see very clearly that it begins rising in lockstep with CO2 concentration right around when people began burning a lot of fossil fuels circa 1800.
Rick Brown owns an adventure tour company called Adventure Sixty North in Seward, Alaska, a small town on an inlet of the Kenai Peninsula. They offer guided hikes and kayaking tours of the surrounding country, including ice hikes on the Exit Glacier.
In this video, Brown talks very simply and powerfully about the changes that he’s witnessed in the glacier and in Alaska in his long career as a guide…like that the Exit Glacier is currently retreating 10 to 15 feet per day.
Normally I think the park will tell you that it retreats about 150 feet per year. Right now they’re looking at 10 to 15 feet per day. You’re seeing the big crevasses that used to be blue up on top of the compression zones now down in the toe of the glacier just falling over. Something that normally would take hundreds of years we’re seeing probably in a matter of a year or two.
We’re seeing a change in the wildlife. We have villages that are being relocated. We get storms up here that if they were happening down in the lower 48, we’d name them something. Our ten-year floods are happening every other year now. You can drive to our town and look at what’s going on, and if you can’t see what’s happening, then I think that you must be blind. Normally I would need a plow here in my office and we need a lawnmower.
While Seward is not quite so far north, I couldn’t help but think of Eric Holthaus’s recent piece on how the fundamental character of the Arctic has changed, possibly for good. Namely, that it won’t be frozen anymore:
Last week, at a New Orleans conference center that once doubled as a storm shelter for thousands during Hurricane Katrina, a group of polar scientists made a startling declaration: The Arctic as we once knew it is no more.
The region is now definitively trending toward an ice-free state, the scientists said, with wide-ranging ramifications for ecosystems, national security, and the stability of the global climate system. It was a fitting venue for an eye-opening reminder that, on its current path, civilization is engaged in an existential gamble with the planet’s life-support system.
In an accompanying annual report on the Arctic’s health — titled “Arctic shows no sign of returning to reliably frozen region of recent past decades” — the National Oceanic and Atmospheric Administration, which oversees all official U.S. research in the region, coined a term: “New Arctic.”
What an astonishing thing. Perhaps in 20 years, when someone over the age of 35 uses a phrase like “Arctic cold” as a stand-in for extremely cold weather, their kids won’t know what the hell they’re referring to. (via @JossFong)
The glaciers of Pine Island Bay are two of the largest and fastest-melting in Antarctica. (A Rolling Stone feature earlier this year dubbed Thwaites “The Doomsday Glacier.”) Together, they act as a plug holding back enough ice to pour 11 feet of sea-level rise into the world’s oceans — an amount that would submerge every coastal city on the planet. For that reason, finding out how fast these glaciers will collapse is one of the most important scientific questions in the world today.
To figure that out, scientists have been looking back to the end of the last ice age, about 11,000 years ago, when global temperatures stood at roughly their current levels. The bad news? There’s growing evidence that the Pine Island Bay glaciers collapsed rapidly back then, flooding the world’s coastlines - partially the result of something called “marine ice-cliff instability.”
The ocean floor gets deeper toward the center of this part of Antarctica, so each new iceberg that breaks away exposes taller and taller cliffs. Ice gets so heavy that these taller cliffs can’t support their own weight. Once they start to crumble, the destruction would be unstoppable.
“Ice is only so strong, so it will collapse if these cliffs reach a certain height,” explains Kristin Poinar, a glaciologist at NASA’s Goddard Space Flight Center. “We need to know how fast it’s going to happen.”
Eleven feet of sea level rise would be, uh, hugely problematic for the world’s coastal areas:
Three feet of sea-level rise would be bad, leading to more frequent flooding of U.S. cities such as New Orleans, Houston, New York, and Miami. Pacific Island nations, like the Marshall Islands, would lose most of their territory. Unfortunately, it now seems like three feet is possible only under the rosiest of scenarios.
At six feet, though, around 12 million people in the United States would be displaced, and the world’s most vulnerable megacities, like Shanghai, Mumbai, and Ho Chi Minh City, could be wiped off the map.
At 11 feet, land currently inhabited by hundreds of millions of people worldwide would wind up underwater. South Florida would be largely uninhabitable; floods on the scale of Hurricane Sandy would strike twice a month in New York and New Jersey, as the tug of the moon alone would be enough to send tidewaters into homes and buildings.
Alarming, but read the whole article. Scientists are still trying to figure out how probable this scenario is…early days still.
Update: The site Climate Feedback, a network of scientists that evaluates media coverage of climate change, recently rated Holthaus’ piece as “high” on the credibility scale and described it as both “accurate” and “alarmist”.
Scientists who reviewed the article found that while it accurately described recent research on these processes, it should have provided more accurate context on the timescale of these sea level rise scenarios and the scientific uncertainty about how likely these scenarios are to come to pass.
Since 1980, the planet has experienced a 50-fold increase in the number of places experiencing dangerous or extreme heat; a bigger increase is to come. The five warmest summers in Europe since 1500 have all occurred since 2002, and soon, the IPCC warns, simply being outdoors that time of year will be unhealthy for much of the globe. Even if we meet the Paris goals of two degrees warming, cities like Karachi and Kolkata will become close to uninhabitable, annually encountering deadly heat waves like those that crippled them in 2015. At four degrees, the deadly European heat wave of 2003, which killed as many as 2,000 people a day, will be a normal summer. At six, according to an assessment focused only on effects within the U.S. from the National Oceanic and Atmospheric Administration, summer labor of any kind would become impossible in the lower Mississippi Valley, and everybody in the country east of the Rockies would be under more heat stress than anyone, anywhere, in the world today. As Joseph Romm has put it in his authoritative primer Climate Change: What Everyone Needs to Know, heat stress in New York City would exceed that of present-day Bahrain, one of the planet’s hottest spots, and the temperature in Bahrain “would induce hyperthermia in even sleeping humans.” The high-end IPCC estimate, remember, is two degrees warmer still.
Carbon is not only warming the atmosphere, it’s also polluting it.
Our lungs need oxygen, but that is only a fraction of what we breathe. The fraction of carbon dioxide is growing: It just crossed 400 parts per million, and high-end estimates extrapolating from current trends suggest it will hit 1,000 ppm by 2100. At that concentration, compared to the air we breathe now, human cognitive ability declines by 21 percent.
Our climate is supposed to move slowly, in concert with many other slow moving things like ecosystems, evolution, global economies, politics, and civilizations. When the pace of climate change quickens? A lot of those slow moving things are going to break. Heat, drought, famine, coastal flooding, pollution, disease, war, forced migration, economic collapse…humanity will survive, but the worst case scenario is not pretty. And of course, the most vulnerable among us — the poor, young children, the elderly, pregnant women, the disabled, and the otherwise disadvantaged — will undergo the most suffering.
I have to say that I am not a fan of this sort of doomist framing. It is important to be up front about the risks of unmitigated climate change, and I frequently criticize those who understate the risks. But there is also a danger in overstating the science in a way that presents the problem as unsolvable, and feeds a sense of doom, inevitability and hopelessness.
The article argues that climate change will render the Earth uninhabitable by the end of this century. Extraordinary claims require extraordinary evidence. The article fails to produce it.
The real problem is that time and time and time again, psychology researchers have found that trying to scare people into action usually backfires. Presented with the idea that the planet that gives us life might be dying, parts of our brain shut down. We are unable to think logically.
Our brain’s limbic system is hard-wired to prioritize these kinds of threats, so we shift into fight-or-flight mode. And because the odds look stacked against us, most choose to flee. If anything, strategies like this make the problem worse. They take people willing to read something like “The Uninhabitable Earth” and essentially remove them from the pool of people working on real-world solutions.
Many climate scientists and professional science communicators say no. Wallace-Wells’s article, they say, often flies beyond the realm of what researchers think is likely. I have to agree with them.
At key points in his piece, Wallace-Wells posits facts that mainstream climate science cannot support. In the introduction, he suggests that the world’s permafrost will belch all of its methane into the atmosphere as it melts, accelerating the planet’s warming in the decades to come. We don’t know everything about methane yet, but the picture does not seem this bleak. Melting permafrost will emit methane, and methane is an ultra-potent greenhouse gas, but scientists do not think so much it will escape in the coming century.
In several places, the story either exaggerates the evidence or gets the science flat-out wrong. This is unfortunate, because it detracts from a well-written, attention-grabbing piece. It’s still worth reading, but with a sharp critical eye.
In recent years, scientific evidence has solidified around central findings, showing that sea level rise is likely to be far more severe during the rest of this century than initially anticipated, and that key temperature thresholds may be crossed that make life difficult for some kinds of plants and animals to survive in certain places.
In Productivity in Terrible Times, Eileen Webb writes about the challenges of getting things done in the face of uncertain and worrisome times and offers some strategies that might help.
When your heart is worried for your Muslim friends, and deep in your bones you’re terrified about losing access to healthcare, it’s very hard to respond graciously to an email inquiring about the latest microsite analytics numbers. “THE WORLD IS BURNING. I will have those content model updates ready by Thursday. Sincerely, and with abject terror, Eileen.”
It is not tenable to quit my job and hie off to Planned Parenthood HQ and wait for them to make use of my superior content organizing skills. It is not a good idea for you to resign from stable work that supports your family and community because you’re no longer satisfied by SQL queries.
I don’t know about you, but I have been struggling mightily with this very thing. I’ve always had difficulty believing that the work I do here is in some way important to the world and since the election, that feeling has blossomed into a profound guilt-ridden anxiety monster. I mean, who in the actual fuck cares about the new Blade Runner movie or how stamps are designed (or Jesus, the blurry ham) when our government is poised for a turn towards corruption and authoritarianism?
I have come up with some reasons why my work here does matter, at least to me, but I’m not sure they’re good ones. In the meantime, I’m pressing on because my family and I rely on my efforts here and because I hope that in some small way my work, as Webb writes, “is capable of enabling righteous acts”.
Update: Meteorologist Eric Holthaus recently shared how he copes with working on climate change day after day.
I’m starting my 11th year working on climate change, including the last 4 in daily journalism. Today I went to see a counselor about it. I’m saying this b/c I know many ppl feel deep despair about climate, especially post-election. I struggle every day. You are not alone. There are days where I literally can’t work. I’ll read a story & shut down for rest of the day. Not much helps besides exercise & time. The counselor said: “Do what you can”, which I think is simple & powerful advice. I’m going to start working a lot more on mindfulness. Despair is natural when there’s objective evidence of a shared existential problem we’re not addressing adequately. You feel alone.
I also wanted to thank those who reached out on Twitter and email about this post…I really appreciate your thoughts. One reader sent along this passage from Italo Calvino’s Invisible Cities:
The inferno of the living is not something that will be; if there is one, it is what is already here, the inferno where we live every day, that we form by being together. There are two ways to escape suffering it. The first is easy for many: accept the inferno and become such a part of it that you can no longer see it. The second is risky and demands constant vigilance and apprehension: seek and learn to recognize who and what, in the midst of inferno, are not inferno, then make them endure, give them space.
The young plaintiffs, who range in age from 9 to 20, allege that climate change violates their constitutional rights to life, liberty, and property by causing direct harm and destroying so-called public trust assets such as coastlines. The case argues that climate change is worsened by the aggregated actions of the federal government in permitting fossil fuel development, subsidizing the fossil fuel industry, and many other such actions. Further, the children and their lawyers say these government actions are willfully prioritizing short-term profit, convenience, and the concerns of current generations over those of future generations. The plaintiffs state that the government and these companies have continued to prioritize these short-term gains for more than five decades with full knowledge of the extreme dangers they posed.
I have no doubt that the right to a climate system capable of sustaining human life is fundamental to a free and ordered society. Just as marriage is the foundation of the family, a stable climate system is quite literally the foundation of society, without which there would be neither civilization nor progress. … To hold otherwise would be to say that the Constitution affords no protection against a government’s knowing decision to poison the air its citizens breathe or the water its citizens drink.
In today’s installment of terrifying graphics about climate change, the NY Times made a series of three maps showing the potential rise of 100 degree temperatures across the United States if current greenhouse gas emission trends continue through the end of this century. Look at the areas in orange and red on the 1991-2010 map: what sort of landscape do you picture? Keeping that landscape picture in your mind, look at the orange and red areas on the 2060 and 2100 maps. Yep! And Phoenix with 163 days above 100 degrees — that’s every day from March 25th to September 4th over 100 degrees.
P.S. A word about climate change and rising temperatures. The temperature that climate scientists typically reference and care about with regard to climate change is “the average global temperature across land and ocean surface areas”. According to the NOAA, the average temperature of the Earth in the 20th century was 13.9°C (57.0°F). In 2015, the average global temperature was 0.90°C (1.62°F) above that.
In order to avoid dangerous effects of climate change, climate scientists advocate keeping the global average temperature increase below 2 degrees (and more recently, below 1.5 degrees). In late 2015, 195 nations came together in Paris and agreed to:
[Hold] the increase in the global average temperature to well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change
That’s degrees Celsius, not Fahrenheit. I don’t know about you, but as an American, when I hear 2 degrees, I think, oh, that’s not bad. But 2°C is an increase of 3.6°F, which does seem significant.
Note also that it specifies keeping the temperature “below pre-industrial levels” and not below 20th century levels. It is maddeningly difficult to track down an exact figure for the pre-industrial global temperature, partially because of a lack of precise data, partially because of politics, and partially because of the impenetrability of scientific writing. From a piece Eric Holthaus wrote for FiveThirtyEight earlier this year:
It sounds easy enough to measure global warming: see how hot it was, compare it to how hot it used to be. But climate scientists have several ways of measuring how hot it used to be. NASA’s base period, as I mentioned above, is an average of 1951-80 global temperatures, mostly because that was the most recently available 30-year period when the data set was first created. By chance, it’s also pretty representative of the world’s 20th-century climate and can help us understand how much warmer the world has become while many of us have been alive.
Other organizations go further back. The Intergovernmental Panel on Climate Change, the body of climate scientists that was formed to provide assessments to the United Nations, bases its temperature calculations on an 1850-1900 global average. There was about 0.4 degrees of warming between that time period and the NASA base period.
Climate scientists often refer to that 1850-1900 timespan as “pre-industrial” because we don’t have comprehensive temperature data from the 1700s. But meteorologist Michael Mann, director of Penn State University’s Earth System Science Center, has argued that an additional 0.25 degrees of warming occurred between the start of the Industrial Revolution (around 1750) and 1850. Including Mann’s adjustment would bring February 2016 global temperatures at or very near 2 degrees above the “pre-industrial” average.
I now completely understand why some people deny that anthropogenic climate change is happening. Seriously. I looked for more than 30 minutes for a report or scientific paper that stated the average global temperature for 1850-1900 and I couldn’t find one. I looked at UN reports, NASA reports, reports from the UK: nothing. There were tons of references to temperatures relative to the 1850-1900 baseline, but no absolute temperatures were given. Now, I don’t mean to get all Feynman here, but this is bullshit. When the world got together in Paris and talked about a 1.5 degree increase, was everyone even talking about the same thing? You might begin to wonder what the scientists are hiding with their obfuscation.
Anyway, the important point is that according to climate scientists, we are already flirting with 1.5°C of global warming since pre-industrial times. Which means that without action, the spread of those Phoenician temperatures across the circa-2100 United States is a thing that’s going to happen.
Citing earlier work from 2007, they estimated anthrax spores remain viable in the permafrost for 105 years. Buried deeper, the bacteria may be able to hibernate for even longer. At the same time, where meteorological data were available they indicate temperatures in Yakutia are increasing.
“As a consequence of permafrost melting, the vectors of deadly infections of the 18th and 19th centuries may come back,” the scientists warned, “especially near the cemeteries where the victims of these infections were buried.” Cattle grave sites should be monitored, they concluded, and “public health authorities should maintain permanent alertness.”
Update: Eric Holthaus talked to some experts and climatologists and yes, pathogens released by warming are something we were warned about and we need to be concerned about it.
Romanovsky says the possibility that additional pathogens may be released from the permafrost, if that is indeed the source, makes it even more important to study this specific outbreak closely. Once in the water supply, in theory, a future pathogen could spread outside the local area, carried by people or by migrating birds or animals.
Though the current outbreak is happening during an unusual period of extreme warmth, Romanovsky says that, “if it gets warmer in the future, and it seems like it will, the thawing permafrost could be massive.” A further degradation of the permafrost would allow more opportunity for the emergence of sequestered microbes.
Joining me with co-hosts Andy Revkin, a veteran environment writer for the New York Times who has covered climate change for 30 years, and Jacquelyn Gill, a paleoecologist at the University of Maine who is an actual, real-life climate scientist and flawlessly navigates climate Twitter.
Also, Holthaus recently started a project on Patreon to support his independent journalism on climate change. I’m in for $3/mo…chip in if you enjoy Eric’s work and Twitter contributions and wish to see more.1
I wish all of Holthaus’ Patreon stuff was public, not just for the people supporting him. I want to fund his current public work and help him create more work that will, hopefully, be disseminated far and wide. The folks that need intelligent writing and podcasting about climate change aren’t the people who are going to back him. I know it’s difficult to make that pitch to people (i.e. you get what everyone else does whether they pay or not), but I think most people are paying to support Holthaus and his work, not to get members-only stuff. ↩
Virtually all climate scientists agree with Dr. Hansen and his co-authors that society is not moving fast enough to reduce emissions of greenhouse gases, posing grave risks. The basic claim of the paper is that by burning fossil fuels at a prodigious pace and pouring heat-trapping gases into the atmosphere, humanity is about to provoke an abrupt climate shift.
Non-linear systems, man. Gradually, then all at once.
In addition to the risk of “several meters” of sea level rise this century, which Hansen calls the most important finding, the final version of Hansen’s paper gives new emphasis to the possibility that the ocean’s heat circulation system may be in the process of shutting down. The circulation shutdown would precede the rapid increase in global sea levels. If the shutdown happens, simultaneous cooling of the waters near Greenland and Antarctica and warming in the tropics and midlatitudes could spawn frequent strong storms on the order of Hurricane Sandy or worse.
In Rolling Stone, Eric Holthaus writes that as far as climate change is concerned, we are already past the point of no return. The things climate scientists have warned against are already beginning to happen…and faster than predicted.
Hansen’s new study also shows how complicated and unpredictable climate change can be. Even as global ocean temperatures rise to their highest levels in recorded history, some parts of the ocean, near where ice is melting exceptionally fast, are actually cooling, slowing ocean circulation currents and sending weather patterns into a frenzy. Sure enough, a persistently cold patch of ocean is starting to show up just south of Greenland, exactly where previous experimental predictions of a sudden surge of freshwater from melting ice expected it to be. Michael Mann, another prominent climate scientist, recently said of the unexpectedly sudden Atlantic slowdown, “This is yet another example of where observations suggest that climate model predictions may be too conservative when it comes to the pace at which certain aspects of climate change are proceeding.”
Since storm systems and jet streams in the United States and Europe partially draw their energy from the difference in ocean temperatures, the implication of one patch of ocean cooling while the rest of the ocean warms is profound. Storms will get stronger, and sea-level rise will accelerate. Scientists like Hansen only expect extreme weather to get worse in the years to come, though Mann said it was still “unclear” whether recent severe winters on the East Coast are connected to the phenomenon.
You might also like to read Adam Sobel’s reaction to this piece. As I wrote in reaction to James Hansen’s recent paper: “That’s the thing about nonlinear systems like the Earth’s climate: things happen gradually, then suddenly.”
Update: A group of climate scientists at Climate Feedback analyzed Holthaus’ piece at his request for accuracy.
While the information within the article is mostly accurate, the main issue for scientists is the article’s framing of the information. More specifically, the article implicitly attributes many weather events to human-induced climate change, while the influence of human activity on these events is not always supported by science, or is at the frontier of scientific knowledge and still debated.
James Hansen, NASA’s former top climate scientist, is joined by 16 other leading climate scientists in a paper with some alarming conclusions. The gist is that the glaciers in Antartica and Greenland are melting so much faster than previously predicted that the global sea level will rise more than 10 feet in as little as 50 years, rendering many coastal cities uninhabitable. From Eric Holthaus in Slate:
The study — written by James Hansen, NASA’s former lead climate scientist, and 16 co-authors, many of whom are considered among the top in their fields — concludes that glaciers in Greenland and Antarctica will melt 10 times faster than previous consensus estimates, resulting in sea level rise of at least 10 feet in as little as 50 years. The study, which has not yet been peer reviewed, brings new importance to a feedback loop in the ocean near Antarctica that results in cooler freshwater from melting glaciers forcing warmer, saltier water underneath the ice sheets, speeding up the melting rate. Hansen, who is known for being alarmist and also right, acknowledges that his study implies change far beyond previous consensus estimates. In a conference call with reporters, he said he hoped the new findings would be “substantially more persuasive than anything previously published.” I certainly find them to be.
Update: In the New Yorker, Elizabeth Kolbert provides a bit more explanation and context about Hansen’s paper.
What the new paper does is look back at a previous relatively warm period, known as the Eemian, or, even less melodically, as Marine Isotope Stage 5e, which took place before the last ice age, about a hundred and twenty thousand years ago. During the Eemian, average global temperatures seem to have been only about one degree Celsius above today’s, but sea levels were several metres higher. The explanation for this, the new paper suggests, is that melt from Antarctica is a non-linear process. Its rate accelerates as fresh water spills off the ice sheet, producing a sort of “lid” that keeps heat locked in the ocean and helps to melt more ice from below. From this, the authors conclude that “rapid sea level rise may begin sooner than is generally assumed,” and also that a temperature increase of two degrees Celsius would put the world well beyond “danger.”
“We conclude that the 2°C global warming ‘guardrail,’ affirmed in the Copenhagen Accord, does not provide safety, as such warming would likely yield sea level rise of several metres along with numerous other severely disruptive consequences for human society and ecosystems,” Hansen and his colleagues wrote.
A recent paper by three climate scientists concludes there’s a high risk of an unprecedented drought in the Southwest and Midwest United States later this century, even if we manage to get our carbon emissions under control. The scientists say it’ll be drier in the Western US than at any point in the past 1000 years.
In the Southwest and Central Plains of Western North America, climate change is expected to increase drought severity in the coming decades. These regions nevertheless experienced extended Medieval-era droughts that were more persistent than any historical event, providing crucial targets in the paleoclimate record for benchmarking the severity of future drought risks. We use an empirical drought reconstruction and three soil moisture metrics from 17 state-of-the-art general circulation models to show that these models project significantly drier conditions in the later half of the 21st century compared to the 20th century and earlier paleoclimatic intervals. This desiccation is consistent across most of the models and moisture balance variables, indicating a coherent and robust drying response to warming despite the diversity of models and metrics analyzed. Notably, future drought risk will likely exceed even the driest centuries of the Medieval Climate Anomaly (1100-1300 CE) in both moderate (RCP 4.5) and high (RCP 8.5) future emissions scenarios, leading to unprecedented drought conditions during the last millennium.
Smerdon’s study is the first to examine the future risk of “megadrought” in the southwest and central United States in the context of historical episodes of drought in the same regions. Smerdon’s study suggests that the coming years are likely to see droughts worse than the epic dry periods that are thought to have caused profound changes to human settlement in the region over the last millennium.
“They’re ‘mega’ because they are droughts that lasted in these regions for multiple decades,” said Smerdon in an interview with Slate. “We haven’t seen anything like this since at least the 1400s.” In comparison, the current California drought is four years old, though drought has been present in most of the last 15 years somewhere in the West.
Update: This NASA video provides a quick overview of this study and what it means for our climate.
Ice has been a relatively constant feature of the Arctic for most of the past 36 million years, but there have been some gaps. Scientists aren’t exactly sure what happened during the most recent major ice-free period, but it’s often considered an analog to our future, warmer Earth. The only difference is, this time, the gap in Arctic sea ice is being caused by us.
Greenland has been covered in dark ice this summer. Why is that such a problem? Because dark things absorb more heat than lighter colored things, causing the dark ice to melt faster than white ice would. Eric Hotlhaus explains.
There are several potential explanations for what’s going on here. The most likely is that some combination of increasingly infrequent summer snowstorms, wind-blown dust, microbial activity, and forest fire soot led to this year’s exceptionally dark ice. A more ominous possibility is that what we’re seeing is the start of a cascading feedback loop tied to global warming. Box mentions this summer’s mysterious Siberian holes and offshore methane bubbles as evidence that the Arctic can quickly change in unpredictable ways.
This year, Greenland’s ice sheet was the darkest Box (or anyone else) has ever measured. Box gives the stunning stats: “In 2014 the ice sheet is precisely 5.6 percent darker, producing an additional absorption of energy equivalent with roughly twice the US annual electricity consumption.”
Perhaps coincidentally, 2014 will also be the year with the highest number of forest fires ever measured in Arctic.
Technically, the storm is a nor’easter but is looking more like a tropical storm in the computer models:
At this point, the most likely scenario would be cold, wind-driven rain in the big coastal US cities, with up to a foot of snow stretching from inland New England as far south as the Carolinas. The cold would stick around after the storm exits, with high temperatures in the 20s and wind chills possibly in the single digits as far south as New Jersey on Black Friday.
According to this afternoon’s iteration of the Euro model (a meteorological model that famously predicted superstorm Sandy’s rare left hook into New Jersey six days out), at the storm’s peak, wind gusts on Cape Cod could approach hurricane force.
We’re still a ways out, so things might change, but travel safely next week, folks. (via @marcprecipice)
There’s a blizzard bearing down on the northeastern United States and here’s some essential information you need to know if you live in an affected area:
But seriously, you should follow @EricHolthaus for the latest storm info. (Ok, so we have our first celebrity Twitter weatherman. Weather and climate are going to become a lot more important in American pop culture…at what point do Gawker or Buzzfeed launch their climate verticals?)
Update: Gawker now has a climate vertical, The Vane. (via @bgporter)
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