Astronomers warn "There's no planet B"

Astronomers usually look to the stars and think about time in terms of billion of years, but recently thousands of them joined together to call for climate action now to preserve the habitability of our one and only Planet Earth.

Last July, under the aegis of Astronomers for Planet Earth, more than 2750 astronomers and astrophysicists from 87 countries signed an open letter focusing attention on and urging immediate and substantial steps to address our current climate crisis.

Earth from Space (Credit: NASA)

"Comprehensive scientific evidence clearly demonstrates that we are living in a climate emergency that calls for urgent action," they warn. If we fail to significantly and continuously reduce global carbon emissions "... we will face both a biodiversity crisis through mass extinctions, and a humanitarian crisis from increasingly inhospitable living conditions."

They add that "... at our current rate of emissions... we are failing to prevent this disaster."

The astronomers also point out that while there may be billions of potentially habitable planets in our galaxy, the Milky Way, not one is within our reach, and even if one were, we have no way to move Earth's 7.75 billion people to it. As one of the signatories, Travis Rector, at the University of Alaska Anchorage explains, "Unfortunately the term 'habitable zone' does not necessarily mean that a planet in this zone is habitable. It simply means that it could in principle have the right conditions for liquid water to be on its surface. It doesn't mean that there actually is water, or that there is life, or that we could actually live there. And even if we could, these exoplanets are so far away we couldn't possibly relocate to them. Mars at its closest is about four light minutes away from us. The nearest star is over four light years. Compare four minutes to four years and you'll get a sense of how much bigger that is. And we can't even yet get one human to Mars, much less all of humanity! It is clear that there truly is 'no Planet B'."

To lead by example, the signatories, who read like a Who's Who of researchers in the field, urge astronomers and their institutions to reduce their own carbon footprint, for example by minimizing the large amount of energy used in computation, and to make environmental sustainability an immediate and primary goal.

Beyond setting an example in their own field and institutions, the astronomers warn that similar steps to reduce carbon emissions and move towards sustainability are urgently needed worldwide. "The climate crisis reaches beyond country borders and individual communities," they point out.

Perhaps nobody has said this more eloquently than the late Carl Sagan, who wrote, "When you look at the Earth from space, it is striking. There are no national boundaries visible. They have been put there, like the equator and the Tropic of Cancer and the Tropic of Capricorn, by humans. The planet is real. The life on it is real, and the political separations that have placed the planet in danger are of human manufacture. They have not been handed down from Mount Sinai. All the beings on this little world are mutually dependent. It's like living in a lifeboat. We breathe the air that Russians have breathed, and Zambians and Tasmanians and people all over the planet. Whatever the causes that divide us, as I said before, it is clear that the Earth will be here a thousand or a million years from now. The question, they key question, the central question, in a certain sense the only question, is, will we?"

Who better to urge us to act now to preserve our only home, Earth, than those who study the stars?

We're going to have to change the calendar . . .

 . . . because plants in the UK are now flowering a full month earlier than before human-caused global heating.

You can find the details of the Cambridge study, which used records from 1793 to 2019 to track the flowering dates of 406 kinds of plants throughout the UK, here.

                                              Spring flowers are showing up a month too soon

Credit: UKgardenpbotos

Hmmm. Could it be that this climate change thing that we've been hearing about is real?

REA 2/3/22

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

TURNING THE CLIMATE CLOCK BACK 3.3 MILLION YEARS

"BY 2025, CO2 LEVELS WILL BE HIGHER THAN THEY'VE BEEN FOR THE LAST 3.3 MILLION YEARS" [Nature Scientific Reports July 10, 2020]

Let's see. What was going on 3.3 million years ago?

--Humans like us were just a gleam in evolution's eye. The most promising potential ancestor around then was Australopithecus, an apelike creature living in southern Africa who may have been the first to use shaped stones to smash open bones for their marrow. 

--Earth wouldn't enter the current geologic epoch, the Holocene, for another 3,288,000 years. It was then in the middle Pliocene. 

--North and South America hadn't yet collided and connected. 

--North America sported two elephant-like species, hyenas, small, three-toed ancestors of modern horses, bone-crushing dogs, giant bears and three species of huge, saber-toothed cats. 

Smilodon populator--one of North America's

Pliocene saber-toothed cats

Credit: Charles Knight/American Museum of Natural History

--Humans wouldn't set foot on the continent for another 3.27 million years.

--Crucially, from our point of view, atmospheric CO2 levels were comparable to today's (somewhere between 381 and 427 parts per million), yet global temperatures were 2 to 3 degrees C (3.6 to 5.4 degrees F) higher than they are now, and sea levels were 25 meters (82 feet) higher. 

Equally crucially, because of those nearly equal CO2 levels, the period tells us what our world may look like all too soon.  "We studied this particular interval in unprecedented detail because it provides great contextual information for our current climate state," says Elwyn de la Vega, researcher at the University of Southampton's School of Ocean and Earth Science, in the UK, and lead author of the Nature Scientific Reports study.

The Southampton research team was able to pin down those ancient CO2 levels by studying the fossilized shells of foraminifera--millimeter-sized sea creatures protected by carbon-rich shells. The ratios of boron isotopes in the shells correlate with atmospheric CO2 levels at the time the shells formed.

Clearly, we're not going to see a return of saber-toothed cats or giant bears. But we, or our children or grandchildren, may well have to deal with a Pliocene climate--much hotter, lacking most of the Northern Hemisphere's ice cover, and with rapidly rising sea levels.

Why aren't we already living in mid-Pliocene conditions? Simply because there hasn't been time for the full impact of the greenhouse gases we've already pumped into the atmosphere to warm the oceans and melt most of Earth's ice. Geochemist Gavin Foster, also at the University of Southampton explains:

... it takes a while for Earth’s climate to fully equilibrate (catch up) to higher CO2 levels and, because of human emissions, CO2 levels are still climbing. Our results give us an idea of what is likely in store once the system has reached equilibrium.

To get a sense of what things will be like when Earth has reached that Pliocene-like equilibrium, picture your favorite coastal city under 80 feet of water. According to recent research, coastal flooding could displace hundreds of millions of people and cost the global economy trillions of dollars by the end of this century if we don't get a grip on climate change now.

Keeling curve--atmospheric CO2 1960-2020

Credit: Scripps Research Insitute

Right now we're at 413 parts per million of atmospheric CO2, and rising, and the curve is getting steeper. We're running as fast as we can towards a very inhospitable past.

--REA

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

EARTH'S VITAL SIGNS: THREE VERY SCARY GRAPHS

For anyone who is not being paid or propagandized to deny global heating, these three graphs say everything that needs to be said:

 Atmospheric CO2 over the last 800,000 years

Credit: NASA

Atmospheric CO2 over the last 60 years

Note that the rate of increase is speeding up!

Credit: ESRL

 Credit: NASA GISS

By the way, today--2/12/20--the Mauna Loa CO2 observatory clocked the highest ever concentration of carbon dioxide in Earth's atmosphere--416.08 parts per million (ppm). Scientists tell us that the safe level is 350 ppm or less.

And the National Oceanic and Atmospheric Administration announced that Earth just experienced the hottest January on record.

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REA

CLIMATE CHANGE "FINGERPRINTS" NOW VISIBLE IN GLOBAL WEATHER EVERY DAY

Talk about thinking outside the box--

For decades now, climate scientists have worked to detect and measure the signal of human-caused climate change over time. They've revealed and warned us about changes in important variables such as atmospheric CO2, sea level and global average temperature; profound changes, but ones that take place over decades.

Climate change deniers, up to and including President Trump, have jumped on the fact that these incremental changes are swamped by much larger local daily and seasonal variability, making it difficult to link climate change to the weather people actually experience--with the fairly recent exception of super-storms or other extreme weather events that would have been extremely unlikely in the absence of global warming.

Now, a team of Swiss and Norweigian researchers has broken the mold. What would they see, they wondered, if they looked at variables such as temperature and humidity across space--the whole Earth--rather than over time. They were prompted to pursue this question by one of Trump's tweets using a major cold spell that hit much of the US to try to ridicule global warming.

"This lead to a lively debate about whether a single day could be informative at all about climate change," says climate scientist Reto Knutti, part of the Swiss-Norwegian research team. "Weather is not climate, yet we are seeing the imprint of climate change now in some single events, e.g. in the frequency of strong heatwaves. But what about the weather on an average day? Could we detect climate change in a single year, a month, a day?"

The answer they found is astonishing. Just by analyzing weather patterns across the globe they were able to detect the fingerprints of climate change on every day's weather since 2012.

Climate scientists can now detect signals of global warming in any day's weather

Image credit: NASA/MODIS

"Global weather is now in uncharted territory," says Knutti. "While locally of course we need a few decades for a signal to emerge from variability, the global information allows us to now detect climate change for any single day since early 2012."

The team used artificial intelligence (AI) to extract indicative patterns from the enormous mass of daily weather data around the globe. They could then test for the probability that the pattern for any given day could have appeared in the absence of climate change.

The daily weather patterns that most powerfully reveal the impact of climate change involve the global distribution of air temperature and humidity. Both variables were more pronounced over oceans than over land masses, and in the tropics compared to higher latitudes.

In retrospect, it may not be surprising that the cumulative heating effect of many decades of climate change is visible in the day-to-day distribution of temperatures across the globe. However, the researchers also found that they could still detect a strong climate change fingerprint in any given day's weather even without looking at temperature--simply from the pattern of atmospheric moisture around the world. "If we include humidity," says Knutti, "we can even detect climate change when we remove the global mean [temperature] signal for every single day, i.e. just by looking at the patterns."

If there was still any legitimate doubt that we humans have changed and are continuing to change the climate and the weather, this new way of charting the relationship between climate and weather should erase it.

Knutti writes, "In the last full IPCC report in 2013 we have shown that humans are the dominant cause of the long-term warming." We now demonstrate that since then we haven't had a single day of 'normal' weather globally. Yesterday was climate change, today is climate change, and tomorrow will be as well. We think this is a powerful message."

We couldn't agree more. The question is, is it powerful enough to get through to the deliberately deaf ears of our leaders?

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You can access the Nature Climate Change article describing this research here.

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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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REMARKABLE 15-YEAR-OLD GRETA THUNBERG SPEAKS TRUTH ABOUT CLIMATE

You may have heard about Greta Thunberg, the 15-year-old Swedish student who made headlines worldwide by skipping school for a month to demand action on climate change by camping out on the steps of the Swedish parliament.

Greta Thunberg and friends

on strike for climate action

Credit: Marc Fermenia

If you haven't heard her remarkable speech at the plenary session of the UN Climate Summit at Katowice, Poland, you need to. Every word rings true, and should make anyone who is not already acting to save the planet get moving now. What an amazing young person--she's like an old-testament prophet in the body of a 15-year-old girl.

You can see her speech here.  Please watch it. Every sentence hits home.

And here's a brief video she made to be played at the Davos meeting of the rich and powerful.

If you need more convincing, you can read more about the importance of her speech at Grist.

And to learn a bit more about this amazing young person, please view her TED talk here. 

And her talk to the British Houses of Parliament: You Did Not Act in Time.

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3/14/19: Just before tomorrow's global youth manifestation for climate action, Ms. Thunberg has been nominated for the Nobel Peace Prize. What an amazing young person!

A MUST-READ ARTICLE ABOUT CLIMATE AND OUR FUTURE

A friend alerted me to a superb and extremely sobering article by Bill McKibben in the November 26, 2018 edition of the New Yorker. Entitled "How Extreme Weather is Shrinking the Planet," the piece lays out in detail the depth of the climate crisis we're in, and how we got here with the help of Exxon, the Koch brothers, Rex Tillerson and decades of dithering or deluded politicians. 

McKibben offers a ray of hope, if we the people, worldwide, can come together and fight against disinformation and special interests for our own survival and the survival of the biosphere that supports us.

The future is here--Southern California wildfire

Credit: FEMA

SCIENTISTS CAN NOW LINK WEATHER EXTREMES TO CLIMATE CHANGE

Climatologists have traditionally been leery of linking a specific event--an extended drought, an exceptional run of hurricanes, massive flooding--to climate change. The most they could be coaxed to say was something along the lines that climate change might have increased the odds of the extreme event, often with a comparison to rolling loaded dice or to an athlete on steroids.

Recently, however, some researchers have started to be more specific. For example, Frederika Otto, a climate scientist at Oxford University, and her colleagues recently reported that South Africa's three-year mega-drought, during which Cape Town came nerve-wrackingly close to running out of water, was demonstrably three times as likely as it would have been without human-caused climate change.

This new capability goes beyond just pinning down the increased odds of an extreme event. In three cases recently, researchers have felt confident enough to say that certain events simply could not have happened without human climate forcing. These included devastating heatwaves in Asia in 2016, the global heat record set the same year, and shockingly high sea temperatures in the Gulf of Alaska and the Bering Sea between 2014 and 2016. 

A review of 170 similar attribution studies between 2004 and 2018 found that two-thirds of the extreme weather events studied were more likely or more intense because of human caused climate forcing.

 South Africa's Theewaterskloof Reservoir, nearly empty on March 11, 2018

Credit: Zaian

So the question is, what's changed? Why are climate scientists now able to make such specific attributions of the impacts of human-caused climate change?

In principle, the answer is remarkably simple. Researchers use multiple state-of-the-art computerized climate models to run thousands of simulations with slightly different initial conditions. Some of the simulations run with current levels of greenhouse gas levels while others use pre-industrial levels. The researchers can then see how many times a comparable event shows up in each scenario. A drought as long and intense as the one that drained Cape Town's reservoirs to the brink of catastrophe happened three times more often under current atmospheric greenhouse gas levels than in models using pre-industrial levels.

In practice, it's a bit more challenging. The multiple computer simulations that are needed are costly and need a lot of time even on the fastest supercomputers. Otto and her colleagues got around this by tapping into weather@home, a network of thousands of volunteers who offer up time on their computer to help perform these massive calculations. In addition, current climate models are not fine-grained enough to model smaller events, such as a crop-destroying hailstorm or an outburst of tornadoes.

Still, scientists now have what it takes to specify to what extent many extreme events, such as a drought, massive flooding or a killer heat wave, can reliably be attributed to human-caused climate change. We can expect much more frequent, accurate and meaningful reports of this kind in the near future.

These attribution studies are not likely to convince dyed-in-the-wool climate change deniers, but they are already proving helpful to planners at all levels. For example, Helen Davies, with the Western Cape's Department of Economic Development and Tourism, now knows that the devastating drought was not a once-in-a-lifetime event. "This is an incredibly strong message which we cannot afford to ignore. We may need to work on a radically new approach to water management."

Otto hopes that this approach will soon be fast and accurate enough to be linked to extreme weather events in real time. Germany may become one of the first countries to do this on a regular basis. 'It’s part of our mission to illuminate the links between climate and weather,” says Paul Becker, Vice President of the German Weather Agency. “There is demand for that information, there is science to provide it, and we are happy to spread it.”

One example of real-time attribution is the assessment by scientists at the Lawrence Berkeley National Laboratory that Hurricane Florence is 50 miles wider and will inundate the Atlantic Coast with 50 percent more rain than a comparable hurricane before human-caused climate change.

And a new study using the supercomputers at the Lawrence Berkeley National Laboratory was able to detail the additional rainfall provoked by global warming in 15 hurricanes that took place in the last ten years, and predict even more rainfall and more intense winds if warming continues.

Let's hope that the entrenched climate change denial on the part of the current US president and congress does not keep this important emerging science from being used here at home.

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The Nature article from which most of this information comes can be found here.

The article summarizing 170 different studies, including a useful interactive map, can be found at this URL.

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WILL CLIMATE-CHANGE DENIERS LEARN FROM PERSONAL EXPERIENCE?

Having followed and written about climate change and the science behind it for decades, I've also had to think a lot about climate-change denial. I've come to realize, ruefully, that science, starting with the most basic physics and including the most powerful supercomputer based climate models, has failed to convince many people who, for one reason or another, are wedded to climate-change denial. Neither have appeals to the health and safety of future generations, nor to the plight of the increasing millions of people whose lives are currently being disrupted by climate change (many of whom become the refugees and migrants whom many climate-change deniers fear).

 More of western US forests are burning every year

Credit: INICIWEB

Through all that I've clung to the idea that when climate change comes home, as it inevitably will, when residents of Florida find their homes flooded because of rising sea levels, when Midwest corn farmers lose ten percent of their crop to extreme heat, when Texas see-saws between drought and floods, or when, as happened to my home town of Santa Rosa, California last year, wildfire sweeps through like a blowtorch, it can no longer be denied. Surely, I've thought, first-hand, life-changing personal experience will break through those layers of denial.

But I'm starting to realize that my faith in personal experience to slap people awake, like my earlier faith in the persuasive effect of science and empathy, is simply naive.

What brought this home to me was an article in the Guardian based on interviews with people who have been impacted by the deadly Northern California Carr fire, which happened to hit a staunchly conservative, Republican, Trump-supporting and climate-change-denying area. The Guardian reporter had no trouble finding people, from politicians to men and women on the street, whose ideas were unchanged even in the midst of the smoke and embers of this deadly fire. "It's bull," said one respondent. And even the one respondent who accepted that climate change was real clung to the meme that we humans are too puny to deal with it, leaving how to fix the problem in the hands of "the good Lord."

There's more evidence in a Guardian story speaking to residents of North Carolina in the aftermath of Hurricane Florence, which climate scientists tell us was 50 miles wider and dropped 50 percent more rain than it would have under pre-industrial conditions. Once again, the reporter found plenty of people still in full climate-change-denial mode.

Scholars who study the history of science often point out that for a new paradigm such as plate tectonics or quantum dynamics to replace an older set of ideas, the old guard simply have to be replaced by a new generation. If scientists, who after all are committed to experiment, hard data and putting every idea to the test, are unwilling or unable to let go of outmoded ways of thinking, I suppose I shouldn't be surprised if everyday people also refuse to learn, even if the lesson is right in front of their eyes.

 Perhaps young people will see more clearly than their elders

Credit: TAKVER

There's still room for hope, if younger generations realize that climate change is real, dangerous, and, can only be dealt with through concerted action. Perhaps Greta Thunberg can be the role model. She's a 15-year-old Swedish girl who is staying out of school and sitting in front of the Swedish Parliament to bring the urgency of the climate crisis home to her elders. Given the feeble steps we've managed to take to date, young people like her may be our last, best hope.

REA
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Here's a related story involving people who have become committed to the idea that vaccination is some kind of dangerous, evil-minded plot. This couple almost lost their six-year-old son to tetanus, a terrible and potentially deadly disease to which most of us are immune because we've been inoculated against it. Doctors were able to save the boy's life, but only through radical interventions and weeks of intensive care, which racked up a bill of over $800,000. Despite this horrifying experience, the parents refused further vaccinations. It used to be said that there's no force on Earth more powerful than an idea whose time has come. Maybe we need to modify that to reflect that, for many people, there's no force on Earth more powerful than an idea that perfectly matches their preconceived view of the world.

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FUEL ON A FIRE--HOW CLIMATE CHANGE MADE HURRICANE HARVEY WORSE

Just a quick link to an important piece by climatologist Michael Mann detailing the ways in which global warming and climate change added destructive power to Hurricane/Tropical Storm Harvey:

https://www.theguardian.com/commentisfree/2017/aug/28/climate-change-hurricane-harvey-more-deadly

The factors Mann details include sea level rise (compounded by subsidence from oil drilling); warmer surface and deep waters in the Gulf which added to the energy/intensity of the storm, the storm surge it caused, and the amount of water it dumped on land; and the fact that it stalled over Texas, producing those all-time-record-breaking rainfall totals.

In the absence of meaningful action to control climate change, we're going to see a lot more of these "once-in-a-thousand-year" disasters.

One of thousands of rescues in the aftermath
of Hurricane/Tropical Storm Harvey
Credit: Dept. of Defense

SOUTH MIAMI BREAKS FROM CLIMATE DENIAL, MANDATES SOLAR PANELS ON NEW CONSTRUCTION

Here's a quicklink to a Cleantechnia,com story about how South Miami is coming to its senses about global warming, climate change and, especially, the region's risk from rising sea levels and storm surges. It's the first city outside of California to mandate solar panels on all new homes.

Tidal flooding on a sunny day, Miami, 2016
Credit: B137

While our leaders at the federal level continue to march backwards with respect to climate change and its impacts, cities like South Miami and states like California and New York are, of necessity, taking the lead.

SEA LEVEL RISE SPEEDING UP

Climate scientists have been concerned about the risks from rising sea levels for nearly 50 years.

That a warming climate will raise sea levels makes intuitive sense--water, including all the water in the world's oceans, expands as it warms, and melt water from glaciers, ice sheets and the Antarcitc ice cap will of course end up in the oceans.

Although the pace of sea level rise seems small, on the order of a millimeter per year, its impact is multiplied by higher tides, stronger storm surges, sea-level-rise hotspots, and by the fact that 634 million people, close to ten percent of the world's population, live in low-lying coastal areas. The US is among the top ten countries with large numbers of people at risk from sea-level rise.

Pinning down the rate of sea level rise has proved to be challenging (see "Sea level measurement" at this URL). Now, however, a team of researchers has used sophisticated statistical techniques to deal systematically with the sources of uncertainty in different sea level data sets. "This likely is the first time a group of statisticians have had really close examination of sea level data," says Andrew Parnell, at University College Dublin.

Their approach allowed them to trace sea level changes over the past 2000 years, with increasing accuracy as more, and more accurate, data have become available in recent decades.

The group found that from 1 AD through 1800 AD, global sea levels rose by much less than one millimeter per year. They began to rise more rapidly at the start of the Industrial Revolution, and are currently not just rising, but rising faster and faster. They estimate that globally the rate is now 1.7 millimeter per year.

"Some people argue that sea levels are not rising," says Parnell. "We are showing them that sea levels are not only rising, but accelerating.

In terms of potential impacts, the East Coast of the US is at particularly high risk. It happens to be one of the sea level rise hotspots. For example, sea level near New York City is rising by 3 millimeters per year, putting more than $25 billion of infrastructure at risk.

New Orleans after Hurricane Katrina

September 11, 2005

Source: NOAA

Author: Lieut. Commander Mark Moran, NOAA Corps, NMAO/AOC

Parnell and his colleagues presented their new findings at the 2017 Joint Statistical Meetings, in Baltimore, Maryland.

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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THE BASIC PHYSICS BEHIND GLOBAL WARMING AND CLIMATE CHANGE HAS BEEN KNOWN FOR MORE THAN A CENTURY

Just a quick link to a great piece by engineering professor John Abraham entitled, "150 Years Ago, Scientists Understood the Climate Better than the EPA Head Does Today."

Here's the URL to click on.

It's worth reading the whole article, in which Abraham vividly reminds us that climate-change deniers such as Scott Pruitt, the current head of the EPA, are basically living in the 1800s, at least as far as their acceptance of the basic science of Earth's radiation balance, the greenhouse effect of atmospheric carbon dioxide and water vapor, and the impact of increased greenhouse gases on Earth's climate, all of which were well known before the turn of the century on New Year's Eve, 1899!

The basic science behind climate change was understood before this car hit the road

Credit: National Motor Museum

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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.