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.
A Siberian heatwave has led to permafrost thaws that have released long-dormant anthrax bacteria, resulting in the hospitalization of 13 people and the death of over 1500 reindeer.
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.”
Another one of those delightful little climate change gotchas, like the near-death of the Great Barrier Reef.
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.
Eric Holthaus, the internet’s favorite meteorologist, is hosting a new podcast on climate change called Warm Regards (on iTunes). A recent episode is embedded above and here’s a bit more about the show, including some info about his co-hosts:
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
A new paper by climate scientists, including ex-NASA scientist James Hansen, warns that our climate could dramatically change within decades, not centuries.
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.
Update: Slate’s Eric Holthaus has more on the paper and its potential implications.
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.
If that sounds a lot like the plot of The Day After Tomorrow to you, you’re not alone.
Hansen also released a 15-minute video about the paper:
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.
That’s the thing about nonlinear systems like the Earth’s climate: things happen gradually, then suddenly. This is much more terrifying to me than the Pacific Northwest earthquake. BTW, as a reminder, here’s what NYC and the surrounding area looks like with 10 more feet of water. Goodbye JFK Airport.
Update: The paper is now available online.
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.
Eric Holthaus has the layperson’s explanation of the study and its implications.
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.
The headline from Eric Holthaus’ latest piece is arresting: The Last Time There Was This Little Arctic Ice, Modern Humans Didn’t Exist.
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.
The internet’s resident meteorologist Eric Holthaus (who incidentally has given up flying because of climate change) warns that a major storm could be on its way to the East Coast in time for Thanksgiving and Hanukkah (which overlap this year and then not again until the year 79811).
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)