Climate change brings world closer to 'doomsday', say scientists

[Earthnut]

https://news.yahoo.com/slowing-ocean-current-could-bring-floods-weird-weather-215244724.html

Scary New Proof That We Have Seriously Screwed Up the Planet's Oceans

By Emily Gertz | Takepart.com

The powerful ocean current that carries tropical warmth from the South Atlantic to northern countries has slowed down to a degree “unprecedented in the past millennium,” according to newly published research. The phenomenon has created an unusual pocket of cooling temperatures in the far North Atlantic, even as global warming heats the world overall.

Yes, it’s the exact climate catastrophy envisioned in The Day After Tomorrow, the 2004 movie about how a slowing current triggers a new ice age and deep freezes New York City. In real life, the current could cause severe coastal flooding between New York and Boston and affect the distribution of marine wildlife, putting coastal fishing industries at risk.

If the slowdown persists or intensifies, weather could significantly change in parts of the Northern Hemisphere that have traditionally been warmed by this current, affecting everything from agriculture to urban transportation.

“These are the kinds of things that scare me,” said oceanographer Scott Rutherford of Roger Williams University in Rhode Island, who coauthored the new study. “How much is this going to change temperature, sea level, marine ecosystems? We’re starting to mess with big things now.

“Can we stop this? Yes,” he said. “We’re already locked into a little bit of warming. I would say that we ought to be concerned with minimizing it as much as we can.”

It’s the first time scientists have analyzed trends in the “Atlantic meridional overturning circulation” (AMOC) over such a lengthy period, which allowed them to contrast its contemporary state to preindustrial conditions and beyond.

The slowdown is one more recent sign that burning fossil fuels, the leading cause of global warming, has fundamentally disrupted the earth’s climate.

Last week the National Snow and Ice Data Center announced that less sea ice formed in the Arctic this winter than at any other time in the 35-year satellite record. The National Oceanic and Atmospheric Administration, meanwhile, announced that globally, the winter of 2014–15 was the warmest ever—except on the East Coast of the United States and in parts of West Africa and Western Europe, all areas that that saw unusually cool or cold weather, and depend on this current to supply them with heat.

The study, published Monday in the journal Nature Climate Change, looked at trends in the current, which flows between North and South America transporting heat northward and cold southward. (The Gulf Stream current that many of us learned about as schoolchildren is a part of this larger circulation.)

In addition to the written record, the researchers used data that came from interpreting nature’s own records—ice and sea sediment core samples, as well as tree rings—to go far back in time.

By deducting sea surface temperatures from averaged land and sea temperatures, they figured out what temperature the current must have been and based on that, determined its salinity and speed.

“For about 900, nearly 1,000 years, the AMOC stays relatively stable," said oceanographer Scott Rutherford of Roger Williams University in Rhode Island. "It bounces around, but it's not until about 1900 that we start to see a relatively steady decline."

“From 1970 to 1990, we see a very rapid drop in temperature” in the current, he added, followed by a warmer period from 1990 to 2010. But “from 2010 we’re starting to see a decline again,” he said.

Both current cooldowns happened shortly after large amounts of freshwater appeared in the North Atlantic. The earlier pulse of freshwater came from a load of Arctic Ocean ice flowing into the North Atlantic; the latest came from Greenland’s glaciers, which have been melting faster since the 1990s.

“It really showed up this past winter in the surface temperature maps," Rutherford said. "That very, very cold spot reappears just south of Greenland.”

Scientifically, “it’s a bit of stretch right now” to link this winter’s record low temperatures and snowfall on much of the East Coast to the slowed ocean current, he said. “But it’s the kind of thing that we might expect to see” based on climate change modeling.

“As a scientist, this is just one more data point to add to our records,” said climate scientist Katharine Hayhoe of Texas Tech University. “As a human, though, it's a stark reminder that our choices have consequences, and the door is rapidly closing on our opportunities to choose a different future."

[Earthnut]

Antarctica hits highest temp recorded—63 F

https://www.cnbc.com/id/102541217?__source=yahoo%7Cfinance%7Cheadline%7Cheadline%7Cstory&par=yahoo&doc=102541217

Antarctica hits highest temp recorded—63 F

Satellite observations from 1994 to 2012 reveal an accelerating decline in Antarctica's massive floating ice shelves, with some shrinking by 18 percent, in a development that could hasten the rise in global sea levels, scientists say, according to scientists published in the journal Science.

Antarctica may have experienced its warmest day ever recorded on Tuesday, with the temperature reading of 63.5°F, reports The Weather Underground.

Tuesday's record high temperature follows another high reading of 63.3°F set just the day before. Until this week's heat wave, the highest-known recorded temperature on the continent was 62.6°F back in 1976.

The Antarctic Peninsula where the readings were made "is one of the fastest warming spots on Earth," reports The Weather Undergound. The website cites studies from 2012 that show the world is warming at a quickening pace.

Five nations and territories have tied or hit all-time high temperature records so far this year.

[Earthnut]

https://news.yahoo.com/ice-around-antarctica-shrank-almost-20-percent-study-004928869.html

Ice around Antarctica has shrunk by almost 20 percent: study

(With Video)

Ice around Antarctica has shrunk by almost 20 percent: study

Washington (AFP) - The ice floating around Antarctica has thinned by nearly 20 percent, according to research, depleting the bulwark that prevents the permanent collapse of glaciers covering the southern continent.

The study, based on satellite measurements between 1994 and 2012 by the European Space Agency, sheds new light on how Antarctic ice responds to climate change.

The report was published on Thursday in the online version of the journal Science.

Ice barriers have an average thickness of between 400 to 500 meters (1,300 to 1,600 feet) and can extend hundreds of kilometers off the coast of Antarctica.

If the ice becomes too thin it would allow the permanent glaciers to slip into the ocean and start melting, sharply increasing the rise of ocean levels.

Researchers found that the total volume of Antarctic ice changed little between 1994 and 2003, but after that point melting markedly accelerated.

Ice in western Antarctica declined throughout the study period. A slight increase in ice thickness was observed in eastern Antarctica before 2003 when rapid melting began, leading to an 18 percent reduction of thickness compared to 1994.

"Eighteen percent over the course of 18 years is really a substantial change," said Fernando Paolo, a researcher at the University of California, San Diego.

"Overall, we show not only the total ice shelf volume is decreasing, but we see an acceleration in the last decade."

If the rate of thinning continues, the ice shelves could lose half of their volume over the next 200 years, the researchers calculated.

For Professor Andrew Shepherd, director of the Centre for Polar Observation and Modelling at the University of Leeds, the melting trend is "a real concern, because such high rates of thinning cannot be sustained for much longer."

A study published in December of 2014 showed that the rate of glacier melting had tripled in the Antarctic region that saw the most ice thinning over the last decade.

Glaciers in the Amundsen Sea of west Antarctica are losing ice faster than anywhere else on the continent and are the largest contributors to the rise of sea levels, researchers said.

Two other studies published in 2014 concluded that the melting of large glaciers in western Antarctica, which have enough water to raise sea levels at least one meter, will accelerate with global warming and the melting is likely irreversible.

[Earthnut]

https://www.grindtv.com/outdoor/nature/post/voracious-sea-lions-invade-columbia-river/

Voracious sea lions invade Columbia River

Pinnipeds are lured in record numbers by millions of smelt, and to the dismay of many they've taken over virtually every inch of dock space in Astoria basin.

California sea lions have flooded into the Columbia River in record numbers, thanks to a phenomenal abundance of smelt during a season in which food has been scarce for the voracious pinnipeds just about everywhere else.

The pinniped invasion has overwhelmed the East Mooring Basin in Astoria, Oregon, where 2,340 sea lions were counted recently. That shatters last year’s record count of 1,420 sea lions, and represents “a mind-boggling number,” Bryan Wright, a spokesman for the Oregon Department of Fish and Wildlife,” told OPB News........................................................

[Earthnut]

https://news.yahoo.com/3-things-know-terrifying-climate-study-221518811.html

Three Things to Know About That Terrifying New Climate Study

James Hansen is one of the most respected and recognizable names in climate science. When this ex-NASA researcher speaks, reasonable people listen.

That good reputation has made his latest research finding that much more frightening.

According to a new paper by Hansen and 16 equally expert coauthors, seas could rise by 10 feet within 50 to 85 years, making coastal communities and cities worldwide uninhabitable.

So, Why Should You Care? That’s much sooner than the forecast of the Intergovernmental Panel on Climate Change, the climate science group of the United Nations, which informs international climate treaty negotiations. IPCC scientists predict sea levels could rise to 2.6 feet by 2100, much lower and later than the Hansen report’s projections.

Hansen and colleagues concluded that to avoid this crisis, global temperature rise must be kept at 2.7 degrees Fahrenheit (1.5 degrees Celsius) or lower, rather than the informal international target of 3.6 degrees Fahrenheit (2 degrees Celsius).

To make that happen, nations would need to slash fossil fuel use nearly to zero within 30 years.

In June, the G-7 major industrialized nations, including the United States, Canada, Japan, the United Kingdom, and Germany, committed to fully phasing out coal, oil, and gas-fueled energy by 2100.

Here are three things to keep in mind about Hansen’s worrying new study.

1. This research paper hasn’t been peer-reviewed—yet.

The peer-review process for traditional scientific journals is meant to weed out poor research from stronger. It’s not a perfect process, but it’s valuable, and it can take many months to play out.

So Hansen and colleagues intend to release their work this week in Atmospheric Chemistry and Physics Discussion, an open-access journal where peer review happens after publication, in public. 

Putting the findings out ahead of peer review isn't traditional for scientists of Hansen's stature and has increased the buzz around the paper and its conclusion about catastrophically high seas in less than a century.

2. A consensus among scientists regarding the study’s conclusions about ice melt and sea-level rise hasn't been reached.

Scientists are still learning how to judge the speed at which the world’s land-bound ice is melting and will continue to melt in coming decades and centuries. We’re also still remarkably ignorant about the oceans, including how currents are affected by changing water conditions.

All these unknowns make melting glaciers and sea-level rise contested arenas in the research world, with significant disagreements among respectable experts over whose ideas are wrong and whose are right. That’s how science rolls.

To reach their conclusions, Hansen and colleagues looked at recent figures on the faster-than-anticipated rate at which the Greenlandic and Antarctic ice caps are melting. They also looked at modeling data and the prehistoric record for the last time Earth’s surface temperatures were as warm as they are now—and sea levels were 30 feet higher.

Based on what those data showed, the authors posit that if the world stays on its course of 3.6 degrees Fahrenheit in temperature rise, contemporary ice caps could hit a tipping point and melt exponentially faster than the more linear rate projected by the IPCC.

This isn't a conclusion that a majority of climate scientists and ice experts yet accept, but it's an analysis that warrants consideration.

3. Hansen and colleagues stated plainly that they published their findings quickly, before peer review, to influence the outcome of the December international climate treaty conference in Paris.

Already some informed observers are suggesting that the unorthodox publishing approach may backfire.

Whether this is good or bad depends on what you think and believe about the intersection of science and climate change with politics. But this much is true: The international climate action process has not slowed global warming. And Hansen and colleagues have been transparent about their motivations.