Friday, 7 April 2017

Abrupt climate change - 04/06/2017

Huge fleet of icebergs hits North Atlantic shipping lanes

About 450 icebergs – up from 37 a week earlier – have drifted into waters where Titanic sank, forcing vessels to divert and raising global warming fears


6 April, 2017


More than 400 icebergs have drifted into the North Atlantic shipping lanes over the past week in an unusually large swarm for this early in the season, forcing vessels to slow to a crawl or take detours of hundreds of kilometres.

Experts are attributing it to uncommonly strong counter-clockwise winds that are drawing the icebergs south, and perhaps also global warming, which is accelerating the process by which chunks of the Greenland ice sheet break off and float way.

As of Monday, there were about 450 icebergs near the Grand Banks of Newfoundland, up from 37 a week earlier, according to the US Coast Guard’s international ice patrol in New London, Connecticut. Those kinds of numbers are usually not seen until late May or early June. The average for this time of year is about 80.

In the waters close to where the Titanic went down in 1912, the icebergs are forcing ships to take precautions.

Instead of cutting straight across the ocean, trans-Atlantic vessels are taking detours that can add around 650km (400 miles) to the trip. That’s a day and a half of added travel time for many large cargo shpis.

Close to the Newfoundland coast, cargo ships owned by Oceanex are throttling way back to three or four knots as they make their way to their home port in St John’s, which can add up to a day to the trip, said executive chairman Captain Sid Hynes.

One ship was pulled out of service for repairs after hitting a chunk of ice, he said.
It makes everything more expensive,” Hynes said. “You’re burning more fuel, it’s taking a longer time, and it’s hard on the equipment.” He called it a “very unusual year”.

US Coast Guard Commander Gabrielle McGrath, who leads the ice patrol, said she had never seen such a drastic increase in such a short time. Adding to the danger, three icebergs were discovered outside the boundaries of the area the Coast Guard had advised mariners to avoid, she said.

McGrath is predicting a fourth consecutive “extreme ice season” with more than 600 icebergs in the shipping lanes.

Most icebergs entering the North Atlantic have “calved” off the Greenland ice sheet. Michael Mann, director of the earth system science center at Pennsylvania State University, said it was possible climate change was leading to more icebergs in the shipping lanes, but wind patterns were also important.

Giant iceberg poised to break off from Antarctic self


In 2014, there were 1,546 icebergs in the shipping lanes – the sixth most severe season on record since 1900, according to the patrol. There were 1,165 icebergs in 2015 and 687 in 2016.

The international ice patrol was formed after the sinking of the Titanic to monitor iceberg danger in the North Atlantic and warn ships. It conducts reconnaissance flights that are used to produce chats.

In 104 years, no ship that has heeded the warnings has struck an iceberg, according to the ice patrol.


In India, it was still February. The hot season was supposed to begin two months later in April. But temperatures in some coastal provinces had already rocketed to above 100 degrees F (38 C).


According to Indian meteorological sources, there are no weather records of temperatures hitting such high marks so fast at any time in at least the past 20 years. Temperatures in late February and March for this region hit a range that is more typical of the height of the hot season from April to May. And when one considers the fact that India has experienced extreme heat and drought for at least the past two years running, the present context is notably disturbing.
(For India, a heatwave that came two months early has already reached an extreme intensity. Yesterday, most of the country saw temperatures above 104 F [40 C] with some locations hitting as high as 113 F [45 C]. Over the coming weeks, this heat is likely to become even more intense. Image source: Earth Nullschool.)

If temperatures started out hot, they’ve only grown hotter. By late March, Nagpur had hit as high as 109 F (43 C ) on Tuesday of last week — its thirteenth straight day of highs above 104 F (40 C). Last week New Dehli saw the end of an 8 day streak of 100 F (38 C) + readings. And places like Bhira were already imposing noon curfews to protect residents from the heat. By April 5, most of the country was experiencing above 100 F (38 C) readings (see above graphic).

Worst Still To Come

Despite precautions to prevent death and injury that began as early as March 8, heat mortality is already a problem. As of March 30th, two deaths had already been reported. And though the mortality is now no-where near the tragedies of past years as 2,000 souls were lost to heat during 2015 and 700 were lost during 2016, the early appearance of killing heat in 2017 does not bode well.

India Heatwave
(Predicted temperature anomalies for April through June of 2017 shows that a severe heatwave is on the way. Image source: Hindustan Times.)
According to meteorological reports, this early heat has set the stage for very extreme conditions from June through April:
The India Meteorological Department’s (IMD) seasonal forecast shows the worst is yet to come, as vast swathes of the country are set to reel under scorching heat from April to June before the monsoon arrives…The forecast is a reflection of the searing heat in most parts of India, including the national capital, since March. New Delhi endured its hottest March in seven years this season, and the mercury is refusing to relent.

As with recent years, and with El Nino emerging in the Equatorial Pacific, there is also now some risk that the Indian Monsoon will again be delayed. So we could end up with a situation where the hot season starts early, becomes very intense in April-June, and ends late.
Conditions in Context

With the Earth now 1.1 to 1.2 C warmer than 1880s values, the climate of India has already changed. Glaciers and snowpacks in the Himalayas are less extensive. Heatwaves and droughts are more intense. And the summer monsoon is often delayed.
(Present extreme heat, drought, and lengthening of the hot season is consistent with the expected impacts of human forced climate change to India. The above graphic lists additional expected impacts for the state. Image source: Climate Change and India.)

Almost every year now, there is news of crippling heat and drought. By late April of 2016, the combination of extreme heat and drought generated severe water stress for 330 million people. This year, the progression of extreme heat and drought has occurred far earlier than normal. And these severe conditions related to human-forced climate change set a very hot and grim stage for India during 2017. As a result, the risk of heat mortality, water stress, crop damage and other heatwave and drought related impacts is very high for India as we enter the months of April and May — when conditions tend to be at their hottest.
Unfortunately, since so much carbon has already been emitted into the Earth’s atmosphere from fossil fuel burning, droughts and heatwaves are likely to continue to become more and more intense for India over at least the next two decades. And the longer large volumes of carbon continue to hit the atmosphere, the worse and worse the situation for India becomes.
(UPDATED)
Links:
Hat tip to Ryan in New England
Hat tip to Spike

Melting Away: Chunk of Antarctic Ice Shelf Hanging ‘By a Thread’

All eyes are on the Larsen C ice shelf in Antarctica, where an iceberg 2,000 square miles in area will soon break away. The only thing keeping the chunk of ice attached to its shelf is a 12-mile “thread” that could vanish at any time.

Larsen C began to calve in summer 2016, and the crack grew rapidly, from 300 feet wide in November to 1,500 feet in February. The crack first formed in 2010 but seemed on the verge of breaking away entirely once calving began, having grown to 110 miles long.

Since February, though, the growth of the crack has slowed to a crawl. "It is particularly hard to predict when it will occur," said Adrian Luckman of Project MIDAS, a British government group that has been monitoring Larsen C for years, in an email to USA Today. "I am quite surprised as to how long it is holding on!"
Antarctic Ice Crack to Produce Monstrous Iceberg Later This Year (VIDEO)
There may be more surprises coming, however, as Luckman pointed out that, "this is not a predictable process because we know only a little about the nature of the ice. It could go today, or it may be months."

Ice shelves already float on top of the water, so the breakaway of a chunk of Larsen C won't raise sea levels very much. A relatively small amount of ice trapped in the ice shelf will fall into the sea when the iceberg completes the process.

The Larsen ice shelf has been slowly disintegrating over the last few decades, with Larsen A breaking away in 1995 and Larsen B in 2002. Larsen C itself isn't going to break away, just a piece of it that makes up about a tenth of its overall area. The piece is still quite large, a good bit larger than the US state of Rhode Island.

Gigantic as the crack is, it will not create a new iceberg. The object will float into the sea, break apart into pieces and then melt into the ocean, according to Project MIDAS.

But for a brief moment between calving and dissolving, the Larsen C chunk will be the fifth largest iceberg on record.



CarbonLevels Could Hit Pre-Human, 'Palms in the Arctic' State byMid-Century


If fossil fuel use continues unabated, atmosphere could revert "to values of CO2 not seen since the early Eocene (50 million years ago)," new report finds


Current carbon dioxide levels are unprecedented in human history and could reach a level unseen in millennia if their rates continue at this pace, a new report out Tuesday warns.

Research published in Nature Communications finds that if fossil fuel use continues unabated, the atmosphere could revert "to values of CO2 not seen since the early Eocene (50 million years ago)," a time when humans did not exist, by the middle of the 21st century.

Dana L. Royer, a paleoclimate researcher at Wesleyan University and co-author of the study, told Climate Central, "The early Eocene was much warmer than today: global mean surface temperature was at least 10°C (18°F) warmer than today. There was little-to-no permanent ice. Palms and crocodiles inhabited the Canadian Arctic."

Because carbon dioxide stays in the atmosphere for centuries, climate change would continue to impact the planet even if humans miraculously dropped emissions to zero after hitting that mid-century peak, Royer said.
Indeed, global warming may have already locked in the Antarctic ice sheet for unstoppable melting—driving sea level rise and threatening coastal communities worldwide.

The authors continue, "If CO2 continues to rise further into the twenty-third century, then the associated large increase in radiative forcing, and how the Earth system would respond, would likely be without geological precedent in the last half a billion years."

The report comes as the Trump administration turns its back on climate regulations, issuing an executive order last week that aims to undo Obama-era policies keeping a lid on greenhouse gas emissions.

"Aside from provoking a large-scale nuclear war, it is hard to imagine an American president taking an action more harmful to the U.S. than [President Donald] Trump's effort to accelerate greenhouse gas emissions," David J. Arkush, managing director of Public Citizen's Climate Program, said at the time.

"This day may be remembered as a low point in human history—a time when the world's preeminent power could have led the world to a better future but instead moved decisively toward catastrophe," Arkush added.

Here is the latest from Paul Beckwith, who seems to be back on-message after lashing out at the NTHE community and Guy McPherson.

Do Jet Streams Vanish with Arctic Sea-Ice?


What happens to the jet streams when we lose all Arctic sea ice and snow cover? Do they vanish? Do they still exist as a weak remnant farther north? Does the 3 cell atmospheric circulation reduce to 2 cells or even 1 cell? It would be nice knowing these things, before they actually happen in a few short years. 


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