March 25, 2015 - EARTH - The
Gulf Stream that helps to keep Britain from freezing over in winter is
slowing down faster now than at any time in the past millennium
according to a study suggesting that major changes are taking place to
the ocean currents of the North Atlantic.
Scientists believe that the huge volumes of freshwater flowing into the North Atlantic from the rapidly melting ice cap of Greenland have slowed down the ocean "engine" that drives the Gulf Stream from the Caribbean towards north-west Europe, bringing heat equivalent to the output of a million power stations.
However, the researchers believe that Britain is still likely to become warmer due to climate change providing the Gulf Stream does not come to a complete halt - although they remain unsure how likely this is.
Calculations suggest that over the 20th century the North Atlantic meridional overturning circulation - the northward flow of warm surface water and the southward flow of deep, cold water - has slowed by between 15 and 20 per cent, said Professor Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany.
"There is more than a 99 per cent probability that this slowdown is unique over the period we looked at since 900 AD. We conclude that the slowdown many have described is in fact already underway and it is outside of any natural variation," Professor Rahmstorf said.
The scientists calculated that some 8,000 cubic kilometres of freshwater has flowed from Greenland into the Atlantic between 1900 and 1970, and this rose significantly to 13,000 cubic kilometres between 1970 and 2000.
Freshwater is lighter than salty water which means that it tends to float on the surface of the ocean and in doing so disturbs the normal sinking of dense, cold saltwater to the ocean floor, which is the main driver of the Atlantic circulation.
In a study published in the journal Nature Climate Change, Professor Rahmstorf and colleagues point out that maps of global surface temperatures have consistently indicated an overall warming trend around the world, except for the region of the North Atlantic south of Greenland.
"It is conspicuous that one specific area of the North Atlantic has been cooling in the past hundred years while the rest of the world heats up," said Professor Rahmstorf, who added that previous research had indicated that a slowdown in ocean currents may be the explanation.
"Now we have detected strong evidence that the global conveyor has indeed been weakening in the past hundred years, particularly since 1970," he said.
The study used proxy measurements of the Atlantic currents, using ice cores, tree rings, coral growth and ocean and lake sediments, to estimate regional temperature variations and so assess how the Gulf Stream has changed over the past 1,000 years.
Jason
Box of the Geological Survey of Denmark and Greenland, who helped to
calculate the amount of freshwater flowing into the Atlantic from
melting ice caps, said that the slowdown can be linked to man-made
climate change.
"Now freshwater coming off the Greenland ice sheet is likely disturbing the circulation. So the human-caused mass loss of the Greenland ice sheet appears to be slowing down the Atlantic overturning, and this effect might increase if temperatures are allowed to rise further," Dr Box said.
Michael Mann of Pennsylvania State University said: "Common climate models are underestimating the change we're facing, wither because the Atlantic overturning is too stable in the models or because they don't properly account for Greenland ice melt, or both."
WATCH: Lord Stirling - Damaged Gulf Stream Affects Jet Stream.
- The Independent.
In the 2004 blockbuster The Day After Tomorrow, abrupt climate change plunges the world into chaos. According to new research published Monday, the idea that underpins the film's plot—that rapid Arctic ice melt could cause dramatic changes to the global climate system—just got one step closer to reality.
Of particular concern are the profound changes happening in the Greenland ice sheet: It appears that the massive amount of freshwater from melting Greenland glaciers has now begun to slow the ocean's circulating currents.
Monday's study, published in the journal Nature Climate Change, is as frightening as it is significant. Among its authors are some of the biggest names in climate science: Jason Box, a glaciologist at the Geological Survey of Denmark and Greenland, whose ongoing "Dark Snow" project is measuring the rapid melting of ice in Greenland; and Michael Mann, a meteorologist at Penn State University, whose famous 1999 "hockey stick" graph showed the sharp influence of human greenhouse gas emissions in context of 1,000 years of temperature data from ice cores and tree rings. Mann's graph was so powerful it became a lightning rod of climate denial.
Fresh water is less dense than saltwater. So when glacial melt from Greenland enters the ocean, it resists the natural sinking motion at the northern edge of the Gulf Stream and slows down the Atlantic's deep current—creating a ripple effect across the entire planet.
The study uses a library of ice cores, tree rings, coral, and sediments to generate a new reconstruction of the historical strength of the Atlantic's circulation based on temperature changes. The team found recent changes in ocean circulation are "unprecedented" since at least the year 900 A.D., about as far back as these proxy data can reliably go. According to the paper, the probability of a similar circulation slowdown caused by natural variability alone (with no influence from human-caused climate change) was less than 0.5 percent.
The effect they identified is "stronger than what current state-of-the-art climate models predict," said Mann, likely due to the increasing influence from a melting Greenland.
But don't expect a new ice age like in the movie. Nearly every square inch of the Earth's surface has been warming for decades now—the 2000s were one of the warmest decades in more than 11,000 years, and the 2010s are on pace to be even hotter. Global warming is still the dominant trend and will overwhelm most of the effect of a slowdown in ocean circulation. But a small portion of the North Atlantic near southern Greenland has bucked the trend. It's here that the new paper focuses its attention. That small patch of ocean actually experienced its coldest three-month stretch on record this past winter.
Despite all the warming that's taken place since 1970, one little blip of the North Atlantic (shown here in green) has begun to actually cool.
In a blog post describing the study, lead author Stefan Rahmstorf of Potsdam University in Germany says this past winter's pronounced cooling in the North Atlantic "suggests the decline of the circulation has progressed even further now than we documented in the paper." Rahmstorf's past work has focused on the impact of climate change on ocean circulations, particularly the thermohaline circulation, Earth's primary oceanic "conveyor belt" circulation, which is driven by geographic differences in temperature and salinity. (Thermo=heat, haline=salt.) That's the same mechanism The Day After Tomorrow identified as a tipping point in the global climate system. (By the way, Rahmstorf is also a fan of The Day After Tomorrow.) Since fresh, warm water is less dense than cold, salty water, scientists like Rahmstorf have long argued the thermohaline circulation may slow down as the climate warms and Arctic ice melts.
Monday's study showed that process has likely already begun. In a press statement, Rahmstorf said, "we have detected strong evidence that the global conveyor has indeed been weakening in the past hundred years, particularly since 1970."
In emails to Slate, both Box and Mann agreed Monday's paper was one of the most important of their careers. "This is yet another example of where observations suggest that climate model predictions may be too conservative when it comes to the pace at which certain aspects of climate change are proceeding," said Mann.
Previous research by Box and others has shown Greenland's melting is accelerating, but the scientific community had been unclear on how fast those changes were impacting ocean circulation. "We now see an effect of Greenland melting besides the obvious sea level rise contribution," said Box.
Now, before you go calling Dennis Quaid for backup as you plot your southward snowshoe journey on I-95, the movie's apocalyptic global-warming-induced cool-down was vastly overdone. In the real world, rapid changes in the climate system take years or decades to play out, not days. Long-term cooling would likely be limited to that spot in the North Atlantic, far from land. But even that seemingly slow rate of change, while not as thrilling on the big screen, has potentially major implications for slow-adapting cities and ecosystems.
"If the slowdown of the Atlantic overturning continues, the impacts might be substantial," says Rahmstorf. "Disturbing the circulation will likely have a negative effect on the ocean ecosystem, and thereby fisheries and the associated livelihoods of many people in coastal areas. A slowdown also adds to the regional sea-level rise affecting cities like New York and Boston." A separate recent study found a sharp 4-inch surge in East Coast sea levelsin just one year, around 2009, that was linked to the slowdown in the Atlantic current as water piled up.
Should melting of Greenland continue to accelerate, there's a small chance that the entire thermohaline circulation could collapse, though that's not likely to happen for several more decades. Still, the implications would be huge: up to 30 inches of extra sea level rise along the East Coast, stronger winter storms, and an interruption of the Atlantic marine food chain. Prior to Monday's study, a survey of experts put the risk of a full collapse scenario at around 10 percent over the next century. Those odds were likely boosted a bit with the new results.
The study comes as the Northeast United States, particularly Boston, finishes one of the coldest and snowiest winters in history—though, in an email to Slate, Mann said it was "unclear" there was any connection between the implications of his new study and the recent spate of cold weather.
WATCH: NASA - The Thermohaline Circulation.
- Slate.
The excessive hail caused a number of emergencies across the city.
The most affected were Santa Isabel, La Fragua and El Restrepo.
The Bogota Fire Department reported that rainfall "generated water depths of between 15 and 20 inches accompanied by ice". However, no cases of gravity are presented.
The first census said at least 500 homes were affected. Late into the night Sunday, backhoes worked on the streets to remove the ice.
Among the most serious events was at a parking lot where the roof collapsed and trapping four adults and three children, rescued by firefighters.
WATCH: Massive hail storm in Bogota.
Entire streets became either covered in ice or formed rivers, while rooftops were damaged and trees fell down.
"Fortunately there are no victims, just material damage," Javier Pava of the Bogota Disaster Rick and Prevention unit was quoted as saying by newspaper El Espectador.
The unit was called to rescue four people from a parking garage where the collapsed roof was impeding the victims from leaving. - Qcostarica.
Weather watchers around the world have been stunned by giant chunks of ice that smashed an outback Queensland town in recent days.
Hailstones up to 12cm in diameter smashed cars and windows and left lawns checkered in the western downs town of Chinchilla during a freak storm on Saturday afternoon.
The downpour that stunned the state has now attracted interest overseas, with many in the US shocked at the "weird" weather that no one saw coming.
Some have pointed out the hailstones were about the same size as the small marsupials the town shares a name with.
"Shocking footage," wrote Keith Estiler, a New York City resident who shared video of the giant balls of ice bouncing off an oval in Chinchilla.
WATCH: Queensland's giant hailstones cause viral news storm.
"Meanwhile in Australia..." another person said.
While intense weather is a typical part of Australian life, the Chinchilla storm that has foreigners talking also managed to surprise locals.
Marina Baker and her children were sprayed with glass when their car was pelted with projectiles at the local sporting fields.
"We had the back window smashed in (and after) about 30 seconds of moving one came through and landed in the back seat," she told ABC.
"The kids were on the floor screaming. We had my sister and husband in the front and they (were) trying to get the kids away from the glass.
"There were cars everywhere around us (with) windows just breaking everywhere."
Another local, Vicki Muhling, shared a photo of one the stones which caused havoc on her property next to a tape measuring 12cm in length.
The region's mayor, Ray Brown, told ABC nobody was injured in the freak storm, though property damage was widespread.
He said some 1300 homes were left without power with another 3000 customers experiencing supply interruptions.
However, draught-stricken farmers in the area welcomed the "much needed rain".
The Bureau of Meteorology said the intensity of the storm was a result of two troughs which caused heavy instability. - Alfred Jacobs Channel [YouTube].
WATCH: 150+ Year Ice Floes Wake the Dead.
150+ year ice flows in Ohio along the Ohio River March 16, 2015 Riverside Cemetery in Maumee, Ohio.
Huge chunks of ice that broke up along a northern Ohio River pushed into a low-lying cemetery and toppled Civil War-era headstones from 1865.
Some parts of Riverside Cemetery were covered with pieces of ice stacked at least 4 feet high. About 90 percent of the headstones, some dating to the mid-1800s, were knocked over, said Joe Camp, the city of Maumee's public service director.
Ice Topples Civil War Cemetary Headstones
http://abcnews.go.com/US/wireStory/ic...
http://www.bellinghamherald.com/2015/...
Ohio River Basin http://www.newworldencyclopedia.org/e...
East USA Ice jams 2014 Rivers http://www.dailymail.co.uk/news/artic...
http://www.blogsmonroe.com/nature/ Maumee River Thaw 2015 at Orleans Park in Perrysburg
http://www.exploringnwo.com/maumee-ri... Maumee River Backup
http://www.kwwl.com/story/28540083/20...
Eliza crossing the ice floes of the Ohio river to freedom, illustration from 'Uncle Tom's Cabin' by Harriet Beecher Stowe, engraved by Charles Bour (1814-81) (litho), Bayot, Adolphe Jean-Baptiste (1810-66)
http://www.allposters.com/-sp/Eliza-C...
- Adapt 2030.
The
most severe hailstorm in 40 years has hit the Mexican state of
Michoacan, destroying avocado crops in some of the country's (and the
world's) most productive municipalities.
The most affected Michoacan municipalities are Ziracuaretiro, San Juan Nuevo, TancÃtaro and Uruapan.
It is estimated that more than 17,000 hectares have been seriously affected, and that the production of other fruits, such as blackberries and blueberries, has also been lost.
The extent of the destruction has been such that it has endangered the health of avocado trees in TancÃtaro, which grows almost 20% of Michaoacan's total annual production, which in turn represents 85% of Mexico's total production.
"In TancÃtaro, there will no longer be any production this season, as the trees will not recover and flower again until November," explained the delegate of the Secretariat of Rural Development (Sedru), Andrés Ciprés MurguÃa.
In San Juan Nuevo and Uruapan, the damage was not as great as in Ziracuaretiro, as due to their warmer climates the fruit was already in a more advanced development stage.
"We were informed that the hailstones were the size of ping-pong balls, and that even some people were injured," stated Andrés. - Fresh Plaza.
But within sight of its destination, the cargo ship, the Arthur M. Anderson, got trapped in ice. Two heavy icebreakers from the Canadian Coast Guard eventually broke the vessel free.
It was a 24-day ordeal, and the ship returned to its home port in Wisconsin without picking up the cargo.
A deep freeze this winter left much of the Great Lakes blanketed in thick ice, sidelining the ship lines and companies that move vast amounts of grain, cement and other commodities through this system of waterways. And now the spring thaw, which creates piles of impassable ice, will most likely create more delays.
"There's a lot of ice out there, and we need to understand the impact of that ice," said Mark Barker, the president of the Interlake Steamship Company, which carries mostly iron ore, coal and limestone on its nine ships. "Last year, we pretty much lost the month of April."
The ship berth of the Mission Terminal grain elevator in Thunder Bay, Ontario. The shipping season has begun, but ice remains.
Cold
spells and snowstorms have taken a bite out of businesses across the
Northeast and Midwest of the United States, as well as in Canada. Car
manufacturers have blamed the weather for weak sales. Housing starts,
too, have slumped. And blizzards in places like Boston have been brutal
for many local businesses.
Michael Dolega, who analyzes the United States economy at the Toronto-Dominion Bank, says he expects that the weather will cut first-quarter growth by as much as three-quarters of a percentage point. And not all of that loss will be made up later in the year, he said.
"I don't think it's a welcome development," said Mr. Dolega, who is based in Toronto.
The Great Lakes shipping trade largely hibernates during the late winter months, with occasional sailings for supplies like road salt. The Arthur M. Anderson was making its last run of the season in early February when it became stuck.
Shipping is usually up and running again by March. But the opening of the St. Lawrence Seaway, the critical system of locks that connects the Atlantic Ocean to the Great Lakes, has been postponed until April 2. Even when the locks open, there is no assurance that all of the lakes, particularly choke points prone to ice buildup, will be navigable.
Last year's ice-induced delays reduced early shipments from the United States by seven million tons, according to the Lake Carriers' Association, which represents American shipowners. That amounts to about 10 percent of all American shipments on the lakes.
The Great Lakes are a vital conduit for companies in a wide range of industries. Grain from farms in Western Canada makes its way to markets around the world. Iron ore travels to steel mills along the shorelines. Power plants depend on the coal that travels via the lakes. Companies in steelmaking, electrical generation, construction and agriculture — like Cargill, United States Steel and Lafarge — all need the waterways.
For companies now facing dwindling stockpiles, there are few alternatives to ships for restocking. Shipping by rail is more costly, even if the tracks were not already overloaded. And hauling large quantities of, say, iron ore by truck is neither practical nor cost-effective. Replacing a single Great Lakes ore-carrying ship requires about 2,400 tractor-trailer trucks.
During a normal winter, some ships can continue to make relatively short treks without much trouble, particularly when ice cover is light. But the last two winters have been particularly harsh.
In 2014, ice cover peaked at 92.5 percent, according to the National Oceanic and Atmospheric Administration's Great Lakes Environmental Research Laboratory in Ann Arbor, Mich. Ice persisted in some places until June. This year, ice cover was 89.1 percent.
"Two especially severe winters back to back — we haven't seen that in a long time," said George A. Leshkevich, who tracks the ice for the research laboratory. "All the lakes seem pretty brutal."
It has created nightmarish troubles for vessels that must continue to attempt runs through the worst of winter.
Truck and train cargo that is too dangerous or too large for the bridge and tunnels spanning the international border between Detroit and Windsor, Ontario, must instead travel the Detroit River. But dense ice stopped the Detroit-Windsor Truck Ferry for 31 days this year, 25 of them consecutively. At one point the ferry's tug was stuck in Windsor with its barge separately frozen to a dock in Detroit.
Ed Bernard, vice president of the Toronto-based Precision Specialized Division, a heavy haul company, said he waited more than two weeks to ferry across the river sections of large chimneys destined for Ohio.
Gregg Ward, the co-owner of the ferry, said, "Our expenses continue, so it's a tragedy for us. By the time this is over, we've lost 20 percent of the year."
As the thaw gets underway, the shipping situation can actually worsen if wind causes ice to pile up in stacks. "I've been on a 235-foot Coast Guard ship going full speed ahead, and when it hit one of those, the ship shuddered to a stop," said Lt. Davey Connor of the Coast Guard district in Cleveland, which is responsible for the Great Lakes.
Many companies are now playing the waiting game.
A United States Coast Guard icebreaker made initial attempts at breaking up ice last week in the port here. Eight imposing grain elevators, which collectively have the largest storage capacity in North America, make the Thunder Bay port an important hub for Canadian exports heading to the Atlantic Ocean.
Once again this year, the season's first ships will not get loaded in March as they normally are. As the Canadian Wheat Board's elevator nears capacity, Paul Kennedy, its manager, says that he may soon be forced to stop daily unloadings of 90 or so rail cars, which have come from the western part of the country.
"They're starting to hunt and peck a little bit for space," Mr. Kennedy said of his employees in the concrete elevator. "You don't want to get to the point where you can't unload any more cars and you've got loaded cars sitting on track."
Railroads impose a $100-a-day charge for every loaded but idle car stuck on their tracks. Last year, when shipping didn't start in Thunder Bay until April 26, Mr. Kennedy estimates that about 2,000 rail cars destined for the eight grain elevators along the city's shoreline were backed up in rail yards.
The delays are just as painful for the companies that depend on the various commodities.
Robert Lewis-Manning, the president of the Canadian Shipowners Association, said that last year, two large steel makers "were getting awfully close to having to lay off people" because their stockpiles of iron ore, coal and coke almost ran out in the spring. He declined to identify the companies.
As his fleet of 22 ships gears up to resume service, Allister Paterson, the president of Canada Steamship Lines, said he expected that the most anxious customers would be suppliers and users of road salt along the lakes and the east coast of North America. With their stocks all but wiped out, such players will need to immediately start the long process of rebuilding.
"They were still recovering from last year, trying to get inventories up," he said. "And now we have another brutal winter, so I suspect they will be in a restocking mode for quite a while." - New York Times.
Warm, moist air will surge into the central and southern Plains to the Ohio Valley at midweek.
The severe weather risk area into Wednesday night is home to approximately 12 million people. The storms have the potential to bring damaging wind gusts, large hail and incidents of flash and urban flooding.
The area that could be hit by dangerous thunderstorms extends from just north and west of Dallas to near St. Louis, Little Rock, Arkansas, and Evansville, Indiana. Locally severe storms are likely to pass through the metro areas of Oklahoma City; Fayetteville, Arkansas; Paducah, Kentucky; and Springfield, Missouri.
People traveling through this area or spending time outdoors in the region should be on the lookout for rapidly changing weather conditions. Seek shelter indoors if a severe thunderstorm or tornado warning is issued.
According to AccuWeather.com Senior Meteorologist Henry Margusity, "While only a small number of tornadoes is likely to occur with this event, the risk for a tornado and damaging wind gusts is slightly elevated in portions of central Oklahoma to north-central Texas and northwestern Arkansas."
Should a tornado occur, it would be the first such storm of the month, not counting waterspouts. The last tornado in the United States was very weak and occurred on Feb. 23, in Kern County, California.
According to AccuWeather Enterprise Solutions Storm Warning Meteorologist Alex Avalos, "Odds are against a more robust severe weather threat from Missouri and southeastern Kansas on eastward with hail and heavy rain being the primary characteristics of the storms."
As a storm system swings to the northeast and chilly air settles in, the risk of severe thunderstorms will diminish by Thursday. However, as the severe thunderstorms collapse, several hours of drenching rain will occur from portions of Arkansas to the Ohio River Basin.
The heavy rainfall will be enough to cause streams to rise and raise new concerns about flooding toward the end of the week. Much of this region has received 3-6 inches of rain plus melting snow earlier in March.
Levels on the lower Ohio to part of the lower Mississippi rivers were hovering at minor to moderate flood stage this week, due to runoff from prior storms and thaw earlier this month.Chilly air will continue to suppress the severe weather risk for most areas east of the Mississippi River into the weekend. - AccuWeather.
Ice age on the way: Gulf Stream is slowing down faster than ever, scientists say
 |
| An iceberg in Ilulissat, Greenland; researchers have been studying the phenomena of the melting glaciers and their long-term ramifications for the rest of the world. © Getty Images |
Scientists believe that the huge volumes of freshwater flowing into the North Atlantic from the rapidly melting ice cap of Greenland have slowed down the ocean "engine" that drives the Gulf Stream from the Caribbean towards north-west Europe, bringing heat equivalent to the output of a million power stations.
However, the researchers believe that Britain is still likely to become warmer due to climate change providing the Gulf Stream does not come to a complete halt - although they remain unsure how likely this is.
Calculations suggest that over the 20th century the North Atlantic meridional overturning circulation - the northward flow of warm surface water and the southward flow of deep, cold water - has slowed by between 15 and 20 per cent, said Professor Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany.
 |
| Gulf Stream stops Britain from freezing over in Winter |
"There is more than a 99 per cent probability that this slowdown is unique over the period we looked at since 900 AD. We conclude that the slowdown many have described is in fact already underway and it is outside of any natural variation," Professor Rahmstorf said.
The scientists calculated that some 8,000 cubic kilometres of freshwater has flowed from Greenland into the Atlantic between 1900 and 1970, and this rose significantly to 13,000 cubic kilometres between 1970 and 2000.
Freshwater is lighter than salty water which means that it tends to float on the surface of the ocean and in doing so disturbs the normal sinking of dense, cold saltwater to the ocean floor, which is the main driver of the Atlantic circulation.
 |
| Scientists believe that huge volumes of freshwater flowing into the North Atlantic from the rapidly melting ice cap of Greenland have slowed down the ocean “engine” that drives the Gulf Stream. © Getty Images |
In a study published in the journal Nature Climate Change, Professor Rahmstorf and colleagues point out that maps of global surface temperatures have consistently indicated an overall warming trend around the world, except for the region of the North Atlantic south of Greenland.
"It is conspicuous that one specific area of the North Atlantic has been cooling in the past hundred years while the rest of the world heats up," said Professor Rahmstorf, who added that previous research had indicated that a slowdown in ocean currents may be the explanation.
"Now we have detected strong evidence that the global conveyor has indeed been weakening in the past hundred years, particularly since 1970," he said.
The study used proxy measurements of the Atlantic currents, using ice cores, tree rings, coral growth and ocean and lake sediments, to estimate regional temperature variations and so assess how the Gulf Stream has changed over the past 1,000 years.
 |
| Machair, a grassy coastal habitat found only in north-west Scotland and the west coast of Ireland, is one of the several elements of the UK’s “cultural heritage” that is at risk from climate change. © Getty Images |
"Now freshwater coming off the Greenland ice sheet is likely disturbing the circulation. So the human-caused mass loss of the Greenland ice sheet appears to be slowing down the Atlantic overturning, and this effect might increase if temperatures are allowed to rise further," Dr Box said.
Michael Mann of Pennsylvania State University said: "Common climate models are underestimating the change we're facing, wither because the Atlantic overturning is too stable in the models or because they don't properly account for Greenland ice melt, or both."
WATCH: Lord Stirling - Damaged Gulf Stream Affects Jet Stream.
- The Independent.
"The Day After Tomorrow" just got one step closer to reality!
 |
| © Joe Raedle/Getty Images |
In the 2004 blockbuster The Day After Tomorrow, abrupt climate change plunges the world into chaos. According to new research published Monday, the idea that underpins the film's plot—that rapid Arctic ice melt could cause dramatic changes to the global climate system—just got one step closer to reality.
Of particular concern are the profound changes happening in the Greenland ice sheet: It appears that the massive amount of freshwater from melting Greenland glaciers has now begun to slow the ocean's circulating currents.
Monday's study, published in the journal Nature Climate Change, is as frightening as it is significant. Among its authors are some of the biggest names in climate science: Jason Box, a glaciologist at the Geological Survey of Denmark and Greenland, whose ongoing "Dark Snow" project is measuring the rapid melting of ice in Greenland; and Michael Mann, a meteorologist at Penn State University, whose famous 1999 "hockey stick" graph showed the sharp influence of human greenhouse gas emissions in context of 1,000 years of temperature data from ice cores and tree rings. Mann's graph was so powerful it became a lightning rod of climate denial.
Fresh water is less dense than saltwater. So when glacial melt from Greenland enters the ocean, it resists the natural sinking motion at the northern edge of the Gulf Stream and slows down the Atlantic's deep current—creating a ripple effect across the entire planet.
The study uses a library of ice cores, tree rings, coral, and sediments to generate a new reconstruction of the historical strength of the Atlantic's circulation based on temperature changes. The team found recent changes in ocean circulation are "unprecedented" since at least the year 900 A.D., about as far back as these proxy data can reliably go. According to the paper, the probability of a similar circulation slowdown caused by natural variability alone (with no influence from human-caused climate change) was less than 0.5 percent.
The effect they identified is "stronger than what current state-of-the-art climate models predict," said Mann, likely due to the increasing influence from a melting Greenland.
But don't expect a new ice age like in the movie. Nearly every square inch of the Earth's surface has been warming for decades now—the 2000s were one of the warmest decades in more than 11,000 years, and the 2010s are on pace to be even hotter. Global warming is still the dominant trend and will overwhelm most of the effect of a slowdown in ocean circulation. But a small portion of the North Atlantic near southern Greenland has bucked the trend. It's here that the new paper focuses its attention. That small patch of ocean actually experienced its coldest three-month stretch on record this past winter.
Despite all the warming that's taken place since 1970, one little blip of the North Atlantic (shown here in green) has begun to actually cool.
In a blog post describing the study, lead author Stefan Rahmstorf of Potsdam University in Germany says this past winter's pronounced cooling in the North Atlantic "suggests the decline of the circulation has progressed even further now than we documented in the paper." Rahmstorf's past work has focused on the impact of climate change on ocean circulations, particularly the thermohaline circulation, Earth's primary oceanic "conveyor belt" circulation, which is driven by geographic differences in temperature and salinity. (Thermo=heat, haline=salt.) That's the same mechanism The Day After Tomorrow identified as a tipping point in the global climate system. (By the way, Rahmstorf is also a fan of The Day After Tomorrow.) Since fresh, warm water is less dense than cold, salty water, scientists like Rahmstorf have long argued the thermohaline circulation may slow down as the climate warms and Arctic ice melts.
Monday's study showed that process has likely already begun. In a press statement, Rahmstorf said, "we have detected strong evidence that the global conveyor has indeed been weakening in the past hundred years, particularly since 1970."
In emails to Slate, both Box and Mann agreed Monday's paper was one of the most important of their careers. "This is yet another example of where observations suggest that climate model predictions may be too conservative when it comes to the pace at which certain aspects of climate change are proceeding," said Mann.
Previous research by Box and others has shown Greenland's melting is accelerating, but the scientific community had been unclear on how fast those changes were impacting ocean circulation. "We now see an effect of Greenland melting besides the obvious sea level rise contribution," said Box.
Now, before you go calling Dennis Quaid for backup as you plot your southward snowshoe journey on I-95, the movie's apocalyptic global-warming-induced cool-down was vastly overdone. In the real world, rapid changes in the climate system take years or decades to play out, not days. Long-term cooling would likely be limited to that spot in the North Atlantic, far from land. But even that seemingly slow rate of change, while not as thrilling on the big screen, has potentially major implications for slow-adapting cities and ecosystems.
"If the slowdown of the Atlantic overturning continues, the impacts might be substantial," says Rahmstorf. "Disturbing the circulation will likely have a negative effect on the ocean ecosystem, and thereby fisheries and the associated livelihoods of many people in coastal areas. A slowdown also adds to the regional sea-level rise affecting cities like New York and Boston." A separate recent study found a sharp 4-inch surge in East Coast sea levelsin just one year, around 2009, that was linked to the slowdown in the Atlantic current as water piled up.
Should melting of Greenland continue to accelerate, there's a small chance that the entire thermohaline circulation could collapse, though that's not likely to happen for several more decades. Still, the implications would be huge: up to 30 inches of extra sea level rise along the East Coast, stronger winter storms, and an interruption of the Atlantic marine food chain. Prior to Monday's study, a survey of experts put the risk of a full collapse scenario at around 10 percent over the next century. Those odds were likely boosted a bit with the new results.
The study comes as the Northeast United States, particularly Boston, finishes one of the coldest and snowiest winters in history—though, in an email to Slate, Mann said it was "unclear" there was any connection between the implications of his new study and the recent spate of cold weather.
WATCH: NASA - The Thermohaline Circulation.
- Slate.
Bogota, Colombia covered in 60 cm (24 inches) of snow and ice from hail storm
Colombia's capital Bogota was surprised on Sunday by a major hail storm that covered the south of the city with a 60 centimeter (24-inch) layer of icy snow.The excessive hail caused a number of emergencies across the city.
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| © COLPRENSA |
The most affected were Santa Isabel, La Fragua and El Restrepo.
The Bogota Fire Department reported that rainfall "generated water depths of between 15 and 20 inches accompanied by ice". However, no cases of gravity are presented.
The first census said at least 500 homes were affected. Late into the night Sunday, backhoes worked on the streets to remove the ice.
Among the most serious events was at a parking lot where the roof collapsed and trapping four adults and three children, rescued by firefighters.
WATCH: Massive hail storm in Bogota.
Entire streets became either covered in ice or formed rivers, while rooftops were damaged and trees fell down.
"Fortunately there are no victims, just material damage," Javier Pava of the Bogota Disaster Rick and Prevention unit was quoted as saying by newspaper El Espectador.
The unit was called to rescue four people from a parking garage where the collapsed roof was impeding the victims from leaving. - Qcostarica.
Giant hailstones fall in Queensland, Australia
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| This shard of hail measuring about 12 centimetres crashed down in Chinchilla on Saturday afternoon |
Weather watchers around the world have been stunned by giant chunks of ice that smashed an outback Queensland town in recent days.
Hailstones up to 12cm in diameter smashed cars and windows and left lawns checkered in the western downs town of Chinchilla during a freak storm on Saturday afternoon.
The downpour that stunned the state has now attracted interest overseas, with many in the US shocked at the "weird" weather that no one saw coming.
Some have pointed out the hailstones were about the same size as the small marsupials the town shares a name with.
"Shocking footage," wrote Keith Estiler, a New York City resident who shared video of the giant balls of ice bouncing off an oval in Chinchilla.
WATCH: Queensland's giant hailstones cause viral news storm.
"Meanwhile in Australia..." another person said.
While intense weather is a typical part of Australian life, the Chinchilla storm that has foreigners talking also managed to surprise locals.
Marina Baker and her children were sprayed with glass when their car was pelted with projectiles at the local sporting fields.
"We had the back window smashed in (and after) about 30 seconds of moving one came through and landed in the back seat," she told ABC.
"The kids were on the floor screaming. We had my sister and husband in the front and they (were) trying to get the kids away from the glass.
"There were cars everywhere around us (with) windows just breaking everywhere."
Another local, Vicki Muhling, shared a photo of one the stones which caused havoc on her property next to a tape measuring 12cm in length.
The region's mayor, Ray Brown, told ABC nobody was injured in the freak storm, though property damage was widespread.
He said some 1300 homes were left without power with another 3000 customers experiencing supply interruptions.
However, draught-stricken farmers in the area welcomed the "much needed rain".
The Bureau of Meteorology said the intensity of the storm was a result of two troughs which caused heavy instability. - Alfred Jacobs Channel [YouTube].
150+ Year Ice Floes Wake the Dead
WATCH: 150+ Year Ice Floes Wake the Dead.
150+ year ice flows in Ohio along the Ohio River March 16, 2015 Riverside Cemetery in Maumee, Ohio.
Huge chunks of ice that broke up along a northern Ohio River pushed into a low-lying cemetery and toppled Civil War-era headstones from 1865.
Some parts of Riverside Cemetery were covered with pieces of ice stacked at least 4 feet high. About 90 percent of the headstones, some dating to the mid-1800s, were knocked over, said Joe Camp, the city of Maumee's public service director.
Ice Topples Civil War Cemetary Headstones
http://abcnews.go.com/US/wireStory/ic...
http://www.bellinghamherald.com/2015/...
Ohio River Basin http://www.newworldencyclopedia.org/e...
East USA Ice jams 2014 Rivers http://www.dailymail.co.uk/news/artic...
http://www.blogsmonroe.com/nature/ Maumee River Thaw 2015 at Orleans Park in Perrysburg
http://www.exploringnwo.com/maumee-ri... Maumee River Backup
http://www.kwwl.com/story/28540083/20...
Eliza crossing the ice floes of the Ohio river to freedom, illustration from 'Uncle Tom's Cabin' by Harriet Beecher Stowe, engraved by Charles Bour (1814-81) (litho), Bayot, Adolphe Jean-Baptiste (1810-66)
http://www.allposters.com/-sp/Eliza-C...
- Adapt 2030.
Worst hailstorm in 40 years destroys avocado crop in Mexico
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| Hailstones. |
The most affected Michoacan municipalities are Ziracuaretiro, San Juan Nuevo, TancÃtaro and Uruapan.
It is estimated that more than 17,000 hectares have been seriously affected, and that the production of other fruits, such as blackberries and blueberries, has also been lost.
The extent of the destruction has been such that it has endangered the health of avocado trees in TancÃtaro, which grows almost 20% of Michaoacan's total annual production, which in turn represents 85% of Mexico's total production.
"In TancÃtaro, there will no longer be any production this season, as the trees will not recover and flower again until November," explained the delegate of the Secretariat of Rural Development (Sedru), Andrés Ciprés MurguÃa.
In San Juan Nuevo and Uruapan, the damage was not as great as in Ziracuaretiro, as due to their warmer climates the fruit was already in a more advanced development stage.
"We were informed that the hailstones were the size of ping-pong balls, and that even some people were injured," stated Andrés. - Fresh Plaza.
Deep freeze over the Great Lakes halts cargo shipments
The trip to pick up a load of iron ore powder in Conneaut, Ohio, was supposed to take four days by way of the Great Lakes.But within sight of its destination, the cargo ship, the Arthur M. Anderson, got trapped in ice. Two heavy icebreakers from the Canadian Coast Guard eventually broke the vessel free.
It was a 24-day ordeal, and the ship returned to its home port in Wisconsin without picking up the cargo.
A deep freeze this winter left much of the Great Lakes blanketed in thick ice, sidelining the ship lines and companies that move vast amounts of grain, cement and other commodities through this system of waterways. And now the spring thaw, which creates piles of impassable ice, will most likely create more delays.
"There's a lot of ice out there, and we need to understand the impact of that ice," said Mark Barker, the president of the Interlake Steamship Company, which carries mostly iron ore, coal and limestone on its nine ships. "Last year, we pretty much lost the month of April."
The ship berth of the Mission Terminal grain elevator in Thunder Bay, Ontario. The shipping season has begun, but ice remains.
Michael Dolega, who analyzes the United States economy at the Toronto-Dominion Bank, says he expects that the weather will cut first-quarter growth by as much as three-quarters of a percentage point. And not all of that loss will be made up later in the year, he said.
"I don't think it's a welcome development," said Mr. Dolega, who is based in Toronto.
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| The ship Arthur M. Anderson got underway on Lake Erie on Saturday after getting help from Canadian Coast Guard icebreakers. © Canadian Coast Guard |
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| The ship berth of the Mission Terminal grain elevator in Thunder Bay, Ontario. The shipping season has begun, but ice remains. © Ian Austen for The New York Times |
The Great Lakes shipping trade largely hibernates during the late winter months, with occasional sailings for supplies like road salt. The Arthur M. Anderson was making its last run of the season in early February when it became stuck.
Shipping is usually up and running again by March. But the opening of the St. Lawrence Seaway, the critical system of locks that connects the Atlantic Ocean to the Great Lakes, has been postponed until April 2. Even when the locks open, there is no assurance that all of the lakes, particularly choke points prone to ice buildup, will be navigable.
Last year's ice-induced delays reduced early shipments from the United States by seven million tons, according to the Lake Carriers' Association, which represents American shipowners. That amounts to about 10 percent of all American shipments on the lakes.
The Great Lakes are a vital conduit for companies in a wide range of industries. Grain from farms in Western Canada makes its way to markets around the world. Iron ore travels to steel mills along the shorelines. Power plants depend on the coal that travels via the lakes. Companies in steelmaking, electrical generation, construction and agriculture — like Cargill, United States Steel and Lafarge — all need the waterways.
For companies now facing dwindling stockpiles, there are few alternatives to ships for restocking. Shipping by rail is more costly, even if the tracks were not already overloaded. And hauling large quantities of, say, iron ore by truck is neither practical nor cost-effective. Replacing a single Great Lakes ore-carrying ship requires about 2,400 tractor-trailer trucks.
During a normal winter, some ships can continue to make relatively short treks without much trouble, particularly when ice cover is light. But the last two winters have been particularly harsh.
In 2014, ice cover peaked at 92.5 percent, according to the National Oceanic and Atmospheric Administration's Great Lakes Environmental Research Laboratory in Ann Arbor, Mich. Ice persisted in some places until June. This year, ice cover was 89.1 percent.
"Two especially severe winters back to back — we haven't seen that in a long time," said George A. Leshkevich, who tracks the ice for the research laboratory. "All the lakes seem pretty brutal."
It has created nightmarish troubles for vessels that must continue to attempt runs through the worst of winter.
Truck and train cargo that is too dangerous or too large for the bridge and tunnels spanning the international border between Detroit and Windsor, Ontario, must instead travel the Detroit River. But dense ice stopped the Detroit-Windsor Truck Ferry for 31 days this year, 25 of them consecutively. At one point the ferry's tug was stuck in Windsor with its barge separately frozen to a dock in Detroit.
Ed Bernard, vice president of the Toronto-based Precision Specialized Division, a heavy haul company, said he waited more than two weeks to ferry across the river sections of large chimneys destined for Ohio.
Gregg Ward, the co-owner of the ferry, said, "Our expenses continue, so it's a tragedy for us. By the time this is over, we've lost 20 percent of the year."
As the thaw gets underway, the shipping situation can actually worsen if wind causes ice to pile up in stacks. "I've been on a 235-foot Coast Guard ship going full speed ahead, and when it hit one of those, the ship shuddered to a stop," said Lt. Davey Connor of the Coast Guard district in Cleveland, which is responsible for the Great Lakes.
Many companies are now playing the waiting game.
A United States Coast Guard icebreaker made initial attempts at breaking up ice last week in the port here. Eight imposing grain elevators, which collectively have the largest storage capacity in North America, make the Thunder Bay port an important hub for Canadian exports heading to the Atlantic Ocean.
Once again this year, the season's first ships will not get loaded in March as they normally are. As the Canadian Wheat Board's elevator nears capacity, Paul Kennedy, its manager, says that he may soon be forced to stop daily unloadings of 90 or so rail cars, which have come from the western part of the country.
"They're starting to hunt and peck a little bit for space," Mr. Kennedy said of his employees in the concrete elevator. "You don't want to get to the point where you can't unload any more cars and you've got loaded cars sitting on track."
Railroads impose a $100-a-day charge for every loaded but idle car stuck on their tracks. Last year, when shipping didn't start in Thunder Bay until April 26, Mr. Kennedy estimates that about 2,000 rail cars destined for the eight grain elevators along the city's shoreline were backed up in rail yards.
The delays are just as painful for the companies that depend on the various commodities.
Robert Lewis-Manning, the president of the Canadian Shipowners Association, said that last year, two large steel makers "were getting awfully close to having to lay off people" because their stockpiles of iron ore, coal and coke almost ran out in the spring. He declined to identify the companies.
As his fleet of 22 ships gears up to resume service, Allister Paterson, the president of Canada Steamship Lines, said he expected that the most anxious customers would be suppliers and users of road salt along the lakes and the east coast of North America. With their stocks all but wiped out, such players will need to immediately start the long process of rebuilding.
"They were still recovering from last year, trying to get inventories up," he said. "And now we have another brutal winter, so I suspect they will be in a restocking mode for quite a while." - New York Times.
Severe Weather Risk of Damaging Winds And Large Hail to Stretch From Texas to Indiana Into Wednesday Night
Severe weather is forecast to develop the Central United States into Wednesday night, impacting a similar area that saw spottystrong storms on Tuesday. A risk of flooding will follow the storms on Thursday.Warm, moist air will surge into the central and southern Plains to the Ohio Valley at midweek.
The severe weather risk area into Wednesday night is home to approximately 12 million people. The storms have the potential to bring damaging wind gusts, large hail and incidents of flash and urban flooding.
The area that could be hit by dangerous thunderstorms extends from just north and west of Dallas to near St. Louis, Little Rock, Arkansas, and Evansville, Indiana. Locally severe storms are likely to pass through the metro areas of Oklahoma City; Fayetteville, Arkansas; Paducah, Kentucky; and Springfield, Missouri.
People traveling through this area or spending time outdoors in the region should be on the lookout for rapidly changing weather conditions. Seek shelter indoors if a severe thunderstorm or tornado warning is issued.
According to AccuWeather.com Senior Meteorologist Henry Margusity, "While only a small number of tornadoes is likely to occur with this event, the risk for a tornado and damaging wind gusts is slightly elevated in portions of central Oklahoma to north-central Texas and northwestern Arkansas."
Should a tornado occur, it would be the first such storm of the month, not counting waterspouts. The last tornado in the United States was very weak and occurred on Feb. 23, in Kern County, California.
According to AccuWeather Enterprise Solutions Storm Warning Meteorologist Alex Avalos, "Odds are against a more robust severe weather threat from Missouri and southeastern Kansas on eastward with hail and heavy rain being the primary characteristics of the storms."
As a storm system swings to the northeast and chilly air settles in, the risk of severe thunderstorms will diminish by Thursday. However, as the severe thunderstorms collapse, several hours of drenching rain will occur from portions of Arkansas to the Ohio River Basin.
The heavy rainfall will be enough to cause streams to rise and raise new concerns about flooding toward the end of the week. Much of this region has received 3-6 inches of rain plus melting snow earlier in March.
Levels on the lower Ohio to part of the lower Mississippi rivers were hovering at minor to moderate flood stage this week, due to runoff from prior storms and thaw earlier this month.Chilly air will continue to suppress the severe weather risk for most areas east of the Mississippi River into the weekend. - AccuWeather.
