Climate Change/Mass Extinction Megathread

[dps]

It is December, but temperatures here still regularly go above 20C, and I still need to switch on the air-conditioner occasionally.  This never happened when I was a kid.

You were thinner, and in better shape.  Now you break into a sweat opening a laptop. 

Plus, when he was a kid, his parents were the ones controlling the heating/cooling setting.

[mongers]

I think 2018 is the year the world should adopt plans for the active management of the atmosphere; we need a plan B.

[grumbler]

I think 2018 is the year the world should adopt plans for the active management of the atmosphere; we need a plan B.

Sounds like a recipe for disaster.

[Savonarola]

Is there a plan for a total ban on diesel fuel in the EU?  Alstom has a new Hydrogen Train.  When introducing it our CEO mentioned something about a diesel ban, and I was wondering if that was planned or just speculation on our part.

(The motors of diesel locomotives actually operate by electricity; the diesel engines power the generators.  So this really isn't a huge change in concept.)

[crazy canuck]

Is there a plan for a total ban on diesel fuel in the EU?  Alstom has a new Hydrogen Train.  When introducing it our CEO mentioned something about a diesel ban, and I was wondering if that was planned or just speculation on our part.

(The motors of diesel locomotives actually operate by electricity; the diesel engines power the generators.  So this really isn't a huge change in concept.)

http://www.independent.co.uk/news/world/paris-copenhagen-oxford-ban-petrol-diesel-cars-emissions-pollution-nitrogen-dioxide-a8000596.html

[Monoriu]

I think 2018 is the year the world should adopt plans for the active management of the atmosphere; we need a plan B.

So who should decide how to do this management?  Seems to me that it is inevitable that such management will result in both losers and winners, and the losers won't just sit there and let their country/region's climate be decided by others.  It isn't far fetched that they'll regard such management as an act of war. 

A real Plan B is to live with the consequences of global warming.

[Ed Anger]

The University of Dayton is installing 4,000 solar panels...to provide 2% their power. Sigh.

[jimmy olsen]

Not looking good.

https://www.ndtv.com/world-news/one-of-the-most-worrisome-predictions-about-climate-change-may-be-coming-true-1841735

One Of The Most Worrisome Predictions About Climate Change May Be Coming True

The new research, based on ocean measurements off the coast of East Antarctica, shows that melting Antarctic glaciers are indeed freshening the ocean around them.

World | (c) 2018 The Washington Post | Chris Mooney, The Washington Post | Updated: April 24, 2018 07:01 IST


One Of The Most Worrisome Predictions About Climate Change May Be Coming True

The new research shows that melting Antarctic glaciers are indeed freshening the ocean

Two years ago, former NASA climate scientist James Hansen and a number of colleagues laid out a dire scenario in which gigantic pulses of fresh water from melting glaciers could upend the circulation of the oceans, leading to a world of fast-rising seas and even superstorms.

Hansen's scenario was based on a computer simulation, not hard data from the real world, and met with skepticism from a number of other climate scientists. But now, a new oceanographic study appears to have confirmed one aspect of this picture - in its early stages, at least.

The new research, based on ocean measurements off the coast of East Antarctica, shows that melting Antarctic glaciers are indeed freshening the ocean around them. And this, in turn, is blocking a process in which cold and salty ocean water sinks below the sea surface in winter, forming "the densest water on the Earth," in the words of study lead author Alessandro Silvano, a researcher with the University of Tasmania in Hobart, Australia.

This so-called Antarctic bottom water has stopped forming in two key regions of Antarctica, the research shows - the West Antarctic coast and the coast around the enormous Totten glacier in East Antarctica.

These are two of Antarctica's fastest-melting regions, and no wonder: When cold surface water no longer sinks into the depths, a deeper layer of warm ocean water can travel across the continental shelf and reach the bases of glaciers, retaining its heat as the cold waters remain above. This warmer water then rapidly melts the glaciers and the large floating ice shelves connected to them.

In other words, the melting of Antarctica's glaciers appears to be triggering a "feedback" loop in which that melting, through its effect on the oceans, triggers still more melting. The melting water stratifies the ocean column, with cold fresh water trapped at the surface and warmer water sitting below Then, the lower layer melts glaciers and creates still more melt water - not to mention rising seas as glaciers lose mass.

"What we found is not only a modeling study but is something that we observed in the real ocean," said Silvano, who conducted the research in Science Advances with colleagues from several other institutions in Australia and Japan. "Our study shows for the first time actual evidence of this mechanism. Our study shows that it is already happening."

Hansen said that "this study provides a nice small-scale example of processes that we talk about in our paper."

"On the large-scale issue, it is too early to say how these feedback processes will play out, based on empirical evidence," Hansen said by email. "If we stay on business-as-usual [greenhouse gas] emissions rates, so that global warming continues to increase, I expect that the freshwater injection rate will increase (mainly via ice faster ice shelf breakup and underwater melt) and sea ice area will increase. This experiment will be playing out over the next years and decades."

According to Matthew Long, an oceanographer at the National Center for Atmospheric Research, the study "is consistent with a large body of existing literature that shows warming and freshening of the deep ocean in the southern hemisphere"

"The fact that we see consistent warming and freshening indicates that the processes we expect to play out over the next century are already underway," Long said. "Indeed, this study is part of a growing body of evidence suggesting that the world's oceans are changing - and that the pace of change is beginning to accelerate."

If the process of Antarctic bottom water formation is being impaired, at least in some regions, then it would be a Southern hemisphere analogue of a process that has already caused great worry and drawn considerably more attention - a potential slowdown of the overturning circulation in the North Atlantic Ocean, thanks to freshening of the ocean from the melting of Greenland.

"Of those two key areas of deep water formation, the northern Atlantic one has been widely considered more vulnerable to global warming," said Stefan Rahmstorf, a scientist at the Potsdam Institute for Climate Impact Research who says he has found changes to the formation of dense deep water in the North Atlantic. "It is therefore of some concern that we now see increasing signs that the deep water formation around Antarctica is already being affected."

Rahmstorf pointed to additional studies which also suggest that Antarctic bottom water formation is changing. In one case, a 2017 study relying on measurements from the Southern Indian Ocean, where Antarctic bottom water travels after leaving the Southern Ocean, found that this deep water has been growing fresher over time, especially in the last decade.

One limitation with the current study, however, is that while the researchers have found that deep water is not forming in two key Antarctic regions, they cannot actually say when a change in these regions occurred. Measurements do not go back far enough for that, said study author Silvano. Thus, it's possible that deep water formation in these regions shut off a long time ago, well before the modern period of intense climate warming. That would make it harder to pin current events on human-caused climate change.

Still, the mechanism detected by the study, in which freshening water from glaciers inhibits the sinking of colder waters at the surface, would presumably continue to apply.

Silvano said his main worry is that in addition to melting by the ocean, Antarctica could also start melting on its surface more if the climate warms further - leading to far more melt water forming in the ocean. So far, unlike in Greenland, this is mostly not happening in Antarctica. But it could.

Silvano also said that if the formation of Antarctic bottom water slows, the global consequences could be massive. The process buries heat, and carbon dioxide, deep beneath the ocean surface - without that process, the heat and CO2 could remain in the atmosphere.

And then, there's the problem of rising sea levels if the feedback between the ocean and the glaciers continues.

"The idea is that this mechanism of rapid melting and warming of the ocean triggered sea level rise at other times, like the last glacial maximum, when we know rapid sea level rise was five meters per century," said Silvano. "And we think this mechanism was the cause of rapid sea level rise"

In the future, he said, "it's possible that with global warming, some other areas of Antarctica will see a complete inhibition of bottom water formation, and then this feedback will kick off."

[Syt]

https://edition.cnn.com/2018/08/01/world/state-of-the-climate-2017-noaa-wxc/index.html

Grim report card for planet ranks 2017 one of hottest years in recorded history

(CNN)Last year was one of the hottest in recorded history, according to a new study released Wednesday by the American Meteorological Society.

The report is another piece of compelling evidence that our planet is warming faster than at any point in modern history. It's the 28th version of the annual checkup for the planet and updates numerous global climate indicators such as polar ice, oceans and extreme weather events around the world.

The State of the Climate in 2017 report, led by National Oceanic and Atmospheric Administration's Centers for Environmental Information, was compiled using contributions from more than 500 scientists in more than 60 countries.

The fact that 2017 was either the second- or third-hottest year, depending on the dataset used, does not come as a surprise. It follows a string of record hot years in 2014, 2015 and 2016 -- and while 2017 did not provide a fourth consecutive record, it was the hottest non-El Niño year seen.

El Niño, which is characterized by a warming of the equatorial Pacific Ocean, tends to warm up the entire planet during years when it occurs.

Conversely, when La Niña is active, it tends to provide some natural air-conditioning for the planet as large portions of the Pacific Ocean cool to below average temperatures. Even though 2017 had a weak La Niña present in the beginning and end of the year, it failed to regulate the planet's high temperature caused by ever-increasing amounts of greenhouse gas concentrations.

The major greenhouse gasses, carbon dioxide (CO2), methane and nitrous oxide, all rose to record high amounts in our atmosphere during 2017, according to the report.

The global average carbon dioxide concentration was 405.0 parts per million (ppm), which is the highest ever recorded and also higher than at any point in the last 800,000 years, according to ice-core data.

The oceans are also heating up, with significant planet-altering consequences.

The global average sea surface temperatures were near a record high, just slightly below the record from 2016, and the last three years have seen the hottest on record.

Warm seas equal rising seas, and 2017 set a new record for global sea level -- which has risen year over year for six consecutive years and 22 of the last 24 years. Global sea level is rising at an average rate of 1.2 inches (3.1 cm) per decade, and that rate has been even higher in the most recent decades as sea-level rise accelerates.

Unprecedented coral bleaching also occurred during 2017, according to the report, which was the most widespread and destructive ever observed with hundreds of miles of corals in the Atlantic, Indian and Pacific Ocean basins experiencing up to 95% mortality in the hardest-hit reefs.

Both the Arctic and the Antarctic saw record low levels of sea ice during 2017, as warmer air and sea surface temperatures continued the trend of thinning out the polar ice.

"Today's abnormally warm Arctic air and sea surface surface temperatures have not been observed in the last 2,000 years," the study said.

In March of 2017, at the end of the ice-growing season when the coverage of sea ice in the Arctic reached its maximum extent of the year, scientists found it was the smallest yearly maximum in the 37-year record.

In the Antarctic, sea ice was below average for all of 2017, hitting record lows during the first four months of 2017. On March 1 it hit a record low extent since satellites began observing the ice in 1978.

As for land ice, the news continues to be grim, which is bad news for global sea levels as melting glaciers are a significant contributor to rising ocean levels.

Glaciers across the globe lost ice mass for the 38th consecutive year -- with declines "remarkably consistent" across all regions of the planet according to the report. To put the amount of ice lost since 1980 into perspective, the report states that "the loss is equivalent to slicing 22 meters (more than 70 feet) off the top of the average glacier."

"Climate is not experienced in annual averages," the report states, even though that is how we most often monitor and gauge the changes in our planet's climate variability -- both natural and human-influenced.

"Humans experience climate change and variability most deeply in the form of impacts and extremes," according to the report --- and 2017 certainly had plenty of them.

Even though globally tropical cyclone (hurricanes, typhoons, tropical storms, etc.) numbers were about average in 2017, the North Atlantic basin had one of it's busiest years on record with three standout hurricanes.

Hurricane Harvey dumped record rainfall totals in Texas and Louisiana, including a new US record of 60.5 inches (1,538 mm) which smashed the old record of 52 inches (1,320 mm).

Right on it's heels came Hurricane Irma, which became the strongest tropical cyclone globally of the year and the strongest Atlantic hurricane outside of the warmest waters of the Gulf of Mexico and Caribbean.

Hurricane Maria immediately followed, bringing catastrophic damage across the Caribbean Islands including devastating the landscape and infrastructure of Puerto Rico.

All three of these hurricanes ranked in the top-5 costliest disasters in US history.

Notable, deadly floods hit every continent except Antarctica -- with India floods claiming 800 lives, Venezuela experienced its most devastating flooding in more than a decade, and flooding of the Niger and Benue Rivers in Nigeria displaced more than 100,000 people.

Global fire activity was the lowest since at least 2003, but extreme droughts in a few key locations led to a number of devastating fire seasons globally.

In the US, an extreme western wildfire season saw over 4 million hectares burned, costing $18 billion -- which tripled the previous US annual wildfire cost record from 1991. Just to the north, Canada's British Columbia saw 1.2 million hectares burn during their driest summer on record.

Spain and Portugal had their second- and third-driest years respectively -- and suffered through an unusually long fire season that claimed over 100 lives.

[Syt]

NYT has a long essay arguing that we missed our chance 30 years ago: https://www.nytimes.com/interactive/2018/08/01/magazine/climate-change-losing-earth.html

[Duque de Bragança]

Is there a plan for a total ban on diesel fuel in the EU?  Alstom has a new Hydrogen Train.  When introducing it our CEO mentioned something about a diesel ban, and I was wondering if that was planned or just speculation on our part.

(The motors of diesel locomotives actually operate by electricity; the diesel engines power the generators.  So this really isn't a huge change in concept.)

For cars in some big cities, not for trains AFAIK. Some train lines are still electrified, once in in a while, to improve service.
The whole Diesel logistic and maintenance chain will take time and money to be substituted. Of course, hydrogen is cleaner than diesel but more flammable. 
In French, engineers like to call those locomotives "diesel-électrique" for the very reason you pointed out.

[Oexmelin]

NYT has a long essay arguing that we missed our chance 30 years ago: https://www.nytimes.com/interactive/2018/08/01/magazine/climate-change-losing-earth.html

When I read that, I am reminded of one of the interpretations of Cortez and the Conquistadors's behavior during the conquest of Mexico. Having committed atrocities upon atrocities for gold, sacrificed much for the ruthless pursuit of wealth meant that every little setback threatened to showcase just how far they had gone, for so little. Rather than lead them to stop, it spurred them on, like a gambler, willing to burn everything, willing to destroy everything in the knowledge that the end would come soon enough. There is an eschatology to capitalism and climate change.

[derspiess]

So capitalism will successfully conquer climate change? 

[crazy canuck]

So capitalism will successfully conquer climate change? 

In a depressing turn of events I mentioned the article to one of my associates. His response was essentially that it is all too complicated and so scientists cannot possibly know.

That person would probably much more readily believe your comment.  It's easy.

[mongers]

So capitalism will successfully conquer climate change? 

In a depressing turn of events I mentioned the article to one of my associates. His response was essentially that it is all too complicated and so scientists cannot possibly know.

That person would probably much more readily believe your comment.  It's easy.

And wilful.

Feigned Ignorance is bliss.