How hot will it get later this century? So hot that we'll need new terms.

 A new study paints a grim climate picture for the Middle East and North Africa (MENA). 

As reported in the prestigious, peer-reviewed journal NPJ/Climate and Atmospheric Science, first-of-their-kind regional climate models project prolonged, life-threatening heat waves impacting up to 600 million people in the MENA region if global warming is not brought under control. In a "business-as-usual" scenario, temperatures are projected to soar to 56 degrees Celsius (133 degrees Fahrenheit) and remain at such intolerable levels for days or weeks at a time in the second half of this century. 

We need new terms to categorize such intense, extended and deadly heat events. "Our results for a business-as-usual pathway indicate that especially in the second half of this century unprecedented super- and ultra-extreme heatwaves will emerge," says George Zittis, first author of the new study.

The authors point out that by mid-century, 90 percent of the population of the MENA region are expected to be living in cities. Cities act as "heat islands" that intensify and prolong extreme heat events. That means that a high percentage of the regions projected population of one billion will face such life-threatening conditions almost every year towards the end of the century.

"For the following decades and towards the end of the 21st century, thermal conditions in the region are projected to become particularly harsh as the so-far-unobserved and thus unprecedented "super-extreme" and "ultra-extreme" events are projected to become commonplace," the authors write.

Daily heat wave magnitude averages from 1980s projected through 2100

Credit: Zittis et al./NPJ/Climate and Atmospheric Science

If the world continues on its current business-as-usual path, the Middle East and North Africa will clearly be at risk, not just of increased human mortality, but of disruption of work, agriculture and daily life. Since the most extreme conditions this study foresees have not yet been experienced, how much personal, social, economic and political disruption they will cause remains to be seen. However, like the heat projections, those disruptions are likely to be extreme, super-extreme or ultra-extreme. And, as we know, problems that start in the Middle East do not stay in the Middle East.

If world leaders needed any more motivation to turn the looming climate catastrophe around now, here it is.

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REA/4-29-21

ANIMATED GRAPH OF ATMOSPHERIC CO2 OVER THE LAST 800000 YEARS AND INTO THE FUTURE

The animated graph linked to below is well worth watching--several times, slowing it down at the end:

https://mobile.twitter.com/OceansClimateCU/status/1237069561364545537?s=20&utm_source=NSDAY&utm_campaign=19fa2fe1ef-NSDAY_110320&utm_medium=email&utm_term=0_1254aaab7a-19fa2fe1ef-373908631

Credit for the above goes to Kris Karnauskas, who leads the Oceans and Climate Lab at the University of Colorado, Boulder.

If we follow the steepest two curves, it really will be the end.

This graph credit: Wikimedia Commons

REA

ONE MORE DEGREE COULD TRIGGER A COLLAPSE OF GREENLAND'S ICE SHEET

The latest and best reconstruction of temperatures near Greenland over that last 450,000 years shows that much of Greenland's vast ice sheet could melt from sustained warming of less than one degree. That means that the world risks triggering a devastating 7 meters (23 feet) of sea-level rise before the end of this century.

 Greenland Ice Sheet at Risk

Credit: cake@cake0

Writing in the prestigious Proceedings of the National Academy of Sciences (PNAS), researchers at the University of Bergen, Norway, and at Rutgers University, New Brunswick, New Jersey, analyze 450,000 years of sea surface temperatures off the coast of Greenland. They were able to track four interglacial (warm) periods, during one of which Greenland's southern ice sheet completely disappeared. During that 30,000-year-long warm period centered around 400,000 years ago, temperatures were only slightly higher than they are today--within one degree C--and well within the projections of climate models for the end of this century--if we continue on a business-as-usual trajectory.

Comparing the four warm periods it became clear that the amount of warming was not the only factor impacting how much of Greenland's ice melted. The other key was the duration of the warming. Even with temperatures just 0.8 degrees C warmer than today, the longer duration of the warm period centered around 400,000 years ago led to almost complete melting of Greenland's southern ice sheet.

According to the authors, their findings support climate models that find a tipping point somewhere between 0.8 and 3.2 degrees C warmer than today, beyond which melting of Greenland's ice sheet is inevitable even if temperatures go back down. Paleoclimatologist Nil Irvali, at the University of Bergen, explains that the tipping point occurs when melting reduces the altitude of the ice surface to the point where the even-warmer temperatures at the lower elevation guarantees runaway melting. "The elevation effect becomes dominant over time," she says, "melting accelerates, and may even continue even though the climate cools again."

The risk, she clarifies, is not that the Greenland Ice Sheet will melt before the end of the century, but that by the end of the century atmospheric warming caused by a continuation of current policies and emissions could easily trigger irreversible melting and an eventual, and devastating, 7-meter sea-level rise.

Actually, Irvali points out, it's even worse than that, since both atmospheric carbon dioxide and warmer ocean waters have extremely long lifetimes. "It is also important to note that CO2 we put into the atmosphere will have a long lifetime even if we cut emissions, and as more and more heat accumulates in the ocean it commits us to a longer timescale of warming," she says, "So our current activities will impact climate for millennia to come."

The authors conclude, "Notably, the critical temperature threshold for past [Greenland Ice Sheet] decay will likely be surpassed this century. The duration for which this threshold is exceeded will determine Greenland's fate."

To which we must add, and the fate of millions of Americans and hundreds of millions of people worldwide.**

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**In case this paleo-historical study seems too theoretical, recent observations by a completely different set of researchers show that Greenland is losing ice 7 times faster than it was two decades ago, in line with the IPCC's worst-case scenario, putting some 400 million people at risk of coastal flooding by 2100.

REA

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TRANSLATE CLIMATE SCIENCE INTO ACTION? NOT WHILE TRUMP'S IN THE WHITE HOUSE

The researchers who leaked the National Climate Assessment in early August did so out of fear that the Trump administration would censor or simply refuse to publish the report--the product of years of work by 13 federal agencies.

Trump has already proved them right by shutting down the advisory committee charged with evaluating and translating the assessment's scientific findings into action.

It's not as though action on climate change isn't urgently needed--the assessment found that temperatures are rising rapidly, especially in the western US and the northern Great Plains; the Atlantic seaboard can expect more destructive hurricanes; California can expect more droughts; the Northeast can expect more deluges and floods; coastal cities will suffer more flooding as sea levels rise; and the risk of irreversible climate tipping points is growing.

Hurricane Isabel hits East Coast of US, 2003
Credit: Wikipedia

With Trump in the White House (or at Mar-a-Lago), and Scott Pruitt in charge of the EPA, the US will not just be ignoring climate change, it will be moving full speed in reverse.

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Click here for an update on this from Grist.

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CLIMATE CHANGE: AS TEMPERATURES SOAR, AIRPLANES CAN'T

On June 19th, the Arizona Republic published this headline:

Nearly 50 flights cancelled Tuesday as Phoenix nears 120-degree day

My first thought was that the tarmac had melted, but of course a modern international airport is paved with concrete, not asphalt. The problem turns out to be basic physics--hot air is less dense than cold air. That's what gives a hot-air balloon lift, but it steals lift from a plane. Every plane has a rated temperature beyond which it can't take off if fully loaded--it can't pick up enough speed to get airborne before running out of runway. 

As the world warms, we can expect more planes stuck at gates

Photo credit: AP

At 120 degrees, smaller commuter aircraft were stuck in Phoenix until the heat abated, while larger, more powerful planes, like the Airbus or the Boeing 747 still had 6 or 7 degrees to spare.

Don't expect this to be an isolated incident, a new study warns. Researchers at Columbia University examined the impact rising temperatures due to global warming will have on 20 major airports worldwide, including Phoenix, Denver, LaGuardia and Ronald Reagan, in Washington, DC. As reported in the journal Climatic Change, under a "business as usual" scenario, on hot days, 10 to 30 percent of flights could be affected and airlines on average would lose about four percent of capacity.

That may not sound like a lot, but since more than 8 million people fly every day, that could mean 320,000 hot and unhappy passengers. In addition, given the slim profit margins of most airlines, that kind of loss could have serious financial implications.

And, the authors point out, those unbearably hot days may come around much more frequently as the atmosphere continues to warm. Daily maximum temperatures at major airports may rise by 4 to 8 degrees C (7.2 to 14.4 F) by 2080 under many scenarios. That would mean far more frequent and intense heat waves and far more delayed, cancelled or weight-restricted flights.

"Our results suggest that weight restriction may impose a non-trivial cost on airline and impact aviation operations around the world," writes lead author Ethan Coffel, at Columbia University.

One more non-trivial reason to take climate change seriously, and do everything we can to slow it down.

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OF BOATS AND BUOYS--OCEAN WARMING "HIATUS" MYSTERY SOLVED

Climate-change deniers were thrilled to report about an apparent slow-down in ocean warming noted in a 2013 IPCC (Intergovernmental Panel on Climate Change) report. For once, it appeared that they had some actual data on their side. They will now have to switch back to denying the data, demeaning the researchers (or following Trump and blaming China for making up the whole concept of climate change), since first NOAA (the National Oceanic and Atmospheric Administration) and now an independent consortium of researchers from the US and the UK have shown that the slowdown didn't happen.

It turns out that the slowdown or "hiatus" was largely the result of inappropriately combining temperature readings from satellites, ships and buoys. Buoys tend to give cooler readings than measurements made aboard ships, so as more buoys came on line in recent years, they produced a false cooling signal.

An ARGO float at work--one way scientists measure ocean temperatures/Credit: UCSD

When the three data sets--from ships, buoys and satellites--are analyzed separately, each shows continuous warming of the oceans averaging 0.12 degrees C (0.22 degrees F) per decade over the past 75 years.

"Our results mean that essentially NOAA got it right, that they were not cooking the books," said Zeke Hausfather, a graduate student in UC Berkeley's Energy and Resources Group and the lead author of the new study, published today in the open-access journal Science Advances.

Note, 1/11/17: It didn't take long for the denial to kick in. A story in the conservative UK Spectator argues that "their case rests on the El Nino temperature increase and will be destroyed when the El Nino subsides, as it is currently doing. A temporary victory over the ‘pause’."

Environmental scientist Dana Nuccitelli promptly destroys that argument by pointing out that if the El Nino years are analyzed separately, they show warming of 0.18 degrees C (0.32 degrees F) per decade over the past fifty years, as do the La Nina years taken separately, with neutral years averaging 0.16 degrees C (0.29 degrees f) per decade.

If you wonder why climate change denial persists in the face of basic physics, decades of research, and a now visibly destabilized climate, please read Naomi Klein's 2014 book, This Changes Everything: Capitalism vs. the Climate. Klein makes the case that conservatives, representatives of the neoliberal market-fundamentalist consensus realized long ago that acceptance of the reality of human-caused climate change would threaten the foundations of the current global economic system. To preserve the system, they have no choice but to deny the reality as long as they can.

WE'VE ALREADY HIT THE 1.5 DEGREE C GLOBAL WARMING CEILING THAT WE'VE AGREED NEVER TO GO BEHOND

Meeting in Paris last year, representatives from 195 nations agreed to work together to limit global warming to 1.5 degrees C (2.7 degrees F) above the temperature that prevailed before the industrial revolution. Scientists and policy members agreed that global warming beyond that level creates unacceptable levels of risk to the environment and civilization--much like revving your car's engine into the red zone. The Paris Agreement (Accord de Paris) went into effect in November of 2016.

Negotiators celebrate Paris Agreement 4/22/16

Credit: UN

In what should serve as a three-alarm wake-up-call, researchers at the European Centre for Medium-Range Weather Forecasts, a prestigious independent intergovernmental organization, reports that Earth hit that 1.5 degree C ceiling for the first time in February of 2016 (see section 10 in the above link).

Global Temperatures 1880 to Present

Credit: NASA GISS

The researchers are quick to note that the early months of 2016 were exceptionally warm, following a strong El Niño, and that Earth has cooled approximately 0.3 degrees C (0.5 degrees F) since then. However, with the levels of carbon dioxide (CO2) and other greenhouse gases in Earth's atmosphere continuing to rise, it's only a matter of time before we don't just bump against the 1.5 degree ceiling, but crash through it.

And not much time. The Berlin-based Mercator Research Institute on Global Commons and Climate Change (MCC) calculates that under the most optimistic assumptions, we have only 4 years before we lock in more than 1.5 degrees C of warming, and under the most pessimistic assumptions, just one year.

Atmosperic CO2 levels over the last 500,000 years/Credit NASA

"It is salutary that the world touched the 1.5 degree C level less that twenty years after touching the 1 degree C level in the record-breaking year of 1998," says Adrian Simmons, the study's lead author. 

"Salutary" is a polite, understated, British way of saying that if we value Earth's health and our own, we'd better pay attention and take action.

(Note 1/10/17: I hate to be pessimistic, but it's clear from Trump's own statements and his appointees that the US government will be leading a climate-change charge, but in exactly the wrong direction--away from wind and other renewable sources of energy, and back towards coal and other greenhouse-gas belching technologies.)

NATURE SHOWING WIDESPREAD CHANGES FROM JUST ONE DEGREE OF WARMING--MORE TO COME

A few years ago I was backpacking in California's Sierra Nevada. Sitting by an alpine lake late in the afternoon, I noticed something interesting. On the hillsides rising up from the lake the stands of pine trees showed a striking pattern. On the lower slopes there were only the remains of dead trees--tall, scraggly skeletons with a few bare branches. A bit higher up the slope was populated by clusters of trees, not the age or height of the dead giants below, but a substantial, growing population. And above them were saplings, staking out still higher ground. "Look at that," I said to my hiking buddies, "the trees are migrating up the slope."

June Lake, Sierra Nevada Range/Credit: Don Graham

At the time, we were pretty sure that we had stumbled upon one, small, local impact of climate change, although of course we knew that what we were seeing could be explained in other ways, and that one case doesn't prove anything.

However, our intuition was probably right. A new study in the prestigious journal Science surveys multiple studies from around the world and finds that 82 percent of the vital biological functions they examined showed clear changes in response to the 1 degree C the Earth has warmed since the beginning of the industrial revolution.

"Genes are changing, species' physiology and physical features such as body size are changing, species are shifting their ranges and we see clear signs of entire ecosystems under stress, all in response to changes in climate on land and in the ocean," says wildlife ecologist Brett Scheffers, at the University of Florida.

Climate change impacts on ecological processes in marine, freshwater, and terrestrial ecosystems/Credit: Scheffers et al., Science, 11 November, 2016

The authors explain that the genetic, physical and population changes they documented represent crucial aspects of the healthy functioning of Earth's ecosystems, biological systems on which human well-being depends. These impacts varied from 60 percent for genetic changes to 100 percent for changes in species distribution. And, these wide-ranging impacts are happening sooner than many experts expected.

"Some people didn't expect this level of change for decades," said environmental researcher James Watson, at the University of Queensland, Australia. "The impacts of climate change are being felt with no ecosystem on Earth being spared."

It's important to recognize that these changes are not just abstractions of interest to scientists and nature lovers. They impact us all directly. The authors write:

Disruptions scale from the gene to the ecosystem and have documented consequences for people, including unpredictable fisheries and crop yields, loss of genetic diversity in wild crop varieties, and increasing impacts of pests and diseases. 

Since we're seeing these across-the-board changes sooner than expected, and with only one degree C of human-caused warming, it becomes all the more urgent to do everything we can to reduce CO2 and other greenhouse gases, and to move as quickly as possible to alternative energy sources such as solar, wind and hydro.

With the coming Trump administration threatening to do everything it can to reverse the progress towards climate-change mitigation that the US has made in recent years, we will have to look to the rest of the world to recognize the need to sustain a healthy and habitable planet, and act to preserve it.

"A HARD RAIN'S A GONNA FALL . . ."

. . . to quote a recent Nobel Prize winner.

We'll no doubt be dealing with the fallout from the election of Donald Trump for many years, if not decades. One of the first, and possibly one of the worst impacts of his presidency may be an about-face by the US concerning greenhouse gas emissions and climate change.

The Paris Climate Agreement may soon be jettisoned by Trump
Credit: UN

Writing in New Scientist, editor Michael Le Page points out that if Trump follows through on his campaign promises, he's likely to derail the fledgling Paris Climate agreement, which will lock the world into at least 3 degrees C of warming, well beyond what scientists tell us is safe.

You can read his commentary here.

And a more in-depth analysis from the Guardian here.

And a piece reaching the same conclusion from the New York Times.

You can read another post about what to expect after Trump's inauguration here.

You get the idea.