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Entries in Global Warming (8)

Thursday
Dec062012

Scientists Say the Arctic Is Getting Warmer and Greener

iStockphoto/Thinkstock(SAN FRANCISCO) -- Climate change is real and it's doing a number on the Arctic, according to the National Oceanic and Atmospheric Administration.

At a conference in San Francisco Wednesday, NOAA scientists revealed that the Arctic has lost a record amount of summer sea ice and late spring snow this year.

NOAA chief Jane Lubechenko says that because of climate change, "the Arctic is warming at more than twice the rate of the rest of the planet."  In fact, she said, it's becoming a greener and warmer place.

The effect is particularly noticable in Greenland, where the melting of the glaciers affects people all over the planet, while in northernmost Europe, the Arctic fox is close to extinction and vulnerable to the encroaching red fox.

Back in the U.S., only 7 percent of the lower 48 states is covered by snow right now compared to 30 percent in 2011.

Overall, the NOAA scientists believe that the trend will be more sea ice melting and less of the years where it builds back up.

Copyright 2012 ABC News Radio

Wednesday
Sep192012

Arctic Sea Ice at Lowest Extent Ever Recorded

iStockphoto/Thinkstock(BOULDER, Colo.) -- Sea ice around the North Pole melted away to record-breaking levels over the summer of 2012, surpassing the previous 2007 record by 293,000 square miles -- an area about the size of Texas.

The northern polar ice cap measured 1.32 million square miles on Sunday, according to the National Snow and Ice Data Center (NSIDC) in Boulder, Colo. The 2007 record was 1.61 million square miles.

The trend continues a downward spiral that a majority of climate scientists say is being accelerated by humans burning fossil fuels, contributing to a greenhouse effect that is warming the planet.

Since 1980, the amount of Arctic ice lost roughly equals the combined area of all states east of the Mississippi, plus Minnesota, Iowa, Missouri, Arkansas, Louisiana, Nebraska, Kansas and the Dakotas, NSIDC director Mark Serreze told ABC News.

“We are now in uncharted territory,” Serreze said.

Scientists have been tracking Arctic ice using satellites since 1979. The ice melts over the summer and then refreezes during winter. Scientists worry, however, that the ice isn’t as “healthy” as it used to be. Thick “multiyear” ice capable of surviving warm summers is increasingly replaced by thinner ice that is more vulnerable to rising temperatures.

As a consequence, disappearing sea ice (which reflects much of the sun’s energy) reveals darker sea water underneath, absorbing more of the sun’s energy and speeding up warming.

The effect of losing what scientists sometimes refer to as “the refrigerator at the top of the planet” goes far beyond the Arctic.

New research suggests a changing Arctic may cause weather patterns like the jet stream to shift, leading to more extreme weather in the United States and around the globe.

While melting sea ice is already floating and does not increase sea level, warming ocean waters can affect what happens in places like Greenland. As ice calves off the land into the water, sea level rises. If Greenland melted away completely (and that won’t happen anytime soon), scientists say global sea level could rise by about 20 feet.

Copyright 2012 ABC News Radio

Monday
Aug272012

Arctic Sea Ice Reaches Record Low 

File photo. Jupiterimages/Thinkstock(BOULDER, Colo.) -- Arctic sea ice is melting faster than climate models projected, already shrinking to a record minimum with several more weeks of this year’s melting season, according to scientists on both sides of the Atlantic.

“The sea ice area went below the sea ice area in 2007 around Aug. 20,” said Ola Johannessen, founding director of the Nansen Environmental and Remote Sensing Center, an independent non-profit research foundation affiliated with the University of Bergen, Norway. The center conducts basic and applied environmental and climate research.

“In general, the ice area and extent has consistently decreased since 1960 and the reason is mainly the increase of CO2,” he said.

According to a report released Monday by U.S. National Snow and Ice Data Center, Arctic sea ice area has shrunk to 1.58 million square miles, breaking the previous minimum of 1.61 million square miles, set in 2007.

There will be both positive and negative effects from the record melting, Johannessen said.

On the positive side, with more water ice-free, the amount of shipping through the Northern Sea Route and the North West Passage, even directly across the Arctic Ocean, will increase.

There could also be increased oil production, since the Arctic holds 32 percent of the world’s untapped oil and gas reserves. Russia has put its first oil rig in the Arctic into operation, but it became a target of environmentalists last week when Greenpeace activists scaled it in protest.

But according to the National Snow and Ice Data Center, the loss of sea could accelerate global warming trends.

Arctic sea ice keeps the polar region cold and helps to moderate global climate. Over the past 30 years there has been a dramatic decrease in the thickness and extent of ice in the arctic.

“Melting of the Arctic is bad for climate change and fisheries,” Johannessen said.  Loss of sea ice will impact “ocean and weather patterns, and there will be increased teleconnection between high and low latitudes affecting the monsoon system in Asia and other parts of the world.”

The melt is also self-reinforcing, scientists agree. Since sea ice is white, it reflects 80 percent of the sunlight hitting it back back into space; the less of it is, the more heat the darker Arctic will absorb. Instead of reflecting 80 percent, it will absorb 90 percent of the sunlight, which will accelerate the thaw, scientists say. Several studies have found the Arctic could be ice free by 2040 or sooner.

As the Arctic melts, the ocean around it becomes warmer, leading to more loss of sea ice, and therefore a rise in sea levels.  Scientists say this sea level rise is impossible to avoid.

The Arctic Ocean has been covered with ice for more than 2.5 million years. During interglacial periods like the current one, ice melts in the summer and thaws in the winter.  Arctic sea ice reaches its maximum seasonal extent in March and shrinks through spring and summer to a minimum extent in September.

Throughout human civilization, this melting and freezing Arctic sea ice has been more or less consistent. However,what is being experienced now is unprecedented, scientists say.

Copyright 2012 ABC News Radio

Sunday
Apr012012

Global Warming Denialism 'Just Foolishness,' Scientist Says

Comstock/Thinkstock(NEW YORK) -- One of the world’s most widely known and respected senior scientists told ABC News that current denial about the basic daunting realities of manmade global warming is “just foolishness.”

He also reports that the rest of the world has now “pretty well given up” on its hope for U.S. leadership in dealing with global climate change.

His assessment reinforces ABC News’ findings at the recent global climate summit in Durban, South Africa, that the vigorous anti-climate science movement in the United States has significantly damaged American prestige among European leaders who are struggling to deal with the daunting impacts of global warming.

Peter Raven, co-inventor in 1964, along with biologist Paul R. Ehrlich, of the bedrock concept of co-evolution, has long been a trusted adviser of American presidents, many other heads of state and government, religious leaders including popes, and countless congressional, academic and scientific leaders in the United States and around the world.

A frequent world traveler for his work, Raven reconfirmed in an email from the international Planet Under Pressure conference in London what he first told ABC News in 2010 in St. Louis.

When asked what he thought about the increasing claims of some parties in the United States that the science and alarm about manmade global warming was “a hoax” or greatly overblown, he responded patiently, “Oh, it’s just foolishness.”

“It’s not a matter of conjecture anymore,” he said. “Climate change is the most serious challenge probably that the human race has ever confronted.”

Raven quickly summarized the virtually unanimous understanding of the world’s climate scientists and other responsible experts about the great upheavals manmade global warming is now producing.

 “There is virtually unanimous consensus among the world’s scientists who work in the area that human beings are the major reason that this is so (the world’s average temperature rising),” Raven wrote from London.

“Because, just as first noted by the Swedish chemist Arrhenius in 1895, when you add more carbon dioxide or other co-called greenhouse gases to the atmosphere, you make it warmer.”

Copyright 2012 ABC News Radio

Tuesday
Feb282012

Is Disappearing Arctic Sea Ice Causing Harsher Winter Storms?

iStockphoto/Thinkstock(ATLANTA) -- New research suggests disappearing sea ice at the top of the planet is playing a “critical” role in driving colder, snowier winters here in the United States.

Retreating Arctic sea ice, according to the researchers, helps alter the atmosphere in two ways.

First, scientists found that less ice is causing a change in atmospheric circulation patterns, weakening the westerly winds that blow across the northern Pacific and Atlantic oceans.  That weakened jet stream, in turn, allows more frequent surges of bitter cold Arctic air not only into the U.S., but also in Europe and east Asia.

“We have more cold air outbreaks,” said Jiping Liu, a senior research scientist in the School of Earth and Atmospheric Sciences at Georgia Tech, and a co-author of the new study released Monday.

The second factor, Liu said, is that more water is evaporating into the air as Arctic ice at the ocean’s surface melts away.

“This greatly enhances the transfer of moisture from the ocean to the atmosphere,” Liu said.  That humidity, he says, essentially acts as fuel to help supercharge “Snowmageddon”-type storms like the ones that paralyzed parts of the northeastern U.S. in 2010.  A more recent, deadly deep freeze in Eastern Europe left 650 people dead.

“The record decline in Arctic sea ice is at least a critical contributor to recent snowy winters in northern continents,” Liu said.

Liu says the new research may also help connect the dots between human-caused global warming, vanishing ice and our changing weather.

Climate researchers believe that the three-decade decline in Arctic sea ice cannot be explained by natural causes alone.  The National Center for Atmospheric Research, for example, recently found that roughly half of Arctic sea ice decline from 1975 to 2005 can be blamed on the increasing amount of climate-changing greenhouse gasses, including carbon dioxide, that humans are releasing into the atmosphere.

“Is Arctic ice in a death spiral?  Maybe not yet, but it’s in big trouble,” Mark Serreze, director of the National Snow and Ice Data Center, recently told ABC News, pointing out that the five lowest amounts of Arctic sea ice on record (since 1979) have all been recorded in the last five years.

If Arctic sea ice continues retreating as expected, the researchers said that “may load the dice” in favor of bigger, more persistent future snowstorms.

Copyright 2012 ABC News Radio

Friday
Feb032012

18-Mile Crack Seen by NASA in Antarctic Glacier

NASA/GSFC/METI/ERSDAC/JAROS; U.S./Japan ASTER Science Team(GREENBELT, Md.) -- Antarctica is so vast that pictures give you no sense of scale.  A pencil-thin line seen across a satellite image of Pine Island Glacier is actually more than 18 miles long, 800 feet across in places, and 180 feet deep.

And it’s growing. In the next few months, scientists expect the glacier to create an iceberg about 350 square miles in area. It will probably float northward, melting as it goes.

“Pine Island Glacier is losing ice very quickly, about six meters per year,” said Michael Studinger of NASA’s Goddard Space Flight Center in Maryland, which sent an expedition called Operation IceBridge to Antarctica in October in an old DC-8 jetliner, modified for scientific operations. It spotted the break in the ice, and earth-observing satellites have been watching it since.

“These things happen on a semi-regular basis in both the Arctic and Antarctic, but it’s still a fairly large event,” said John Sonntag, Instrument Team Lead for Operation IceBridge, in a video recorded on the plane. “So we wanted to make sure we captured as much of that process as we could."

“A lot of times when you’re in science, you don’t get to capture the big stories as they happen, because you’re not there at the right place at the right time,” he said, “but this time we were.”

To scientists, this is more than a vast spectacle. Both polar caps are losing ice, and researchers studying the world’s climate say they want to understand the process.

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Copyright 2012 ABC News Radio

Friday
Nov182011

Climate Change Report: Weather Extremes Increasing

Comstock/Thinkstock(GENEVA) -- A new report on the effects of a warming climate on the world’s weather by the United Nations-sponsored Intergovernmental Panel on Climate Change (IPCC) says that much of the world is already seeing more weather “extremes” -- stronger hurricanes and more intense heat waves -- at least partly because of the buildup of greenhouse gases in the atmosphere.

A draft summary of the report, called “Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation,” or “SREX” for short, was obtained by ABC News.

Here is a sampling of some of its findings:

On temperatures: “It is very likely that there has been an overall decrease in the number of cold days and nights, and an overall increase in the number of warm days and nights, on the global scale, i.e., for most land areas with sufficient data.”

On whether human beings are contributing to the change: “It is likely that anthropogenic influences have led to warming of extreme daily minimum and maximum temperatures on the global scale.  There is medium confidence that anthropogenic influences have contributed to intensification of extreme precipitation on the global scale.  It is likely that there has been an anthropogenic influence on increasing extreme sea levels via mean sea level contributions.”

On hurricanes and tropical storms: “Mean tropical cyclone maximum wind speed is likely to increase, although increases may not occur in all ocean basins.  It is likely that the global frequency of tropical cyclones will either decrease or remain essentially unchanged.”

A summary of the report is now up on the IPCC's website [click here to read it].  The full report will be available in February 2012, according to the site.

The report is dense, and addresses a subject that provokes strong and opposing opinions.  In part because of this, definitions of basic terms have been negotiated.  For instance, “likely” means at least a 66 percent probability that a conclusion is true, and “very likely” means at least a 90 percent probability.

Copyright 2011 ABC News Radio

Tuesday
Sep132011

Arctic Sea Ice: Why Pay Attention, Record or No Record?

Michael Blann/Thinkstock(BREMEN, Germany) -- Did Arctic sea ice melt to a record-low level this summer? Researchers at the University of Bremen in Germany believe that it did, dipping 27,000 square kilometers below the previous record low set in 2007.

However, U.S. scientists at the National Snow and Ice Data Center in Boulder, Colo., are not ready to declare that the extent of Arctic sea ice has dropped below the record level.  At this point, the expectation is that 2011 will rank second -- right behind 2007 -- for record Arctic sea ice melt. Scientists at the International Arctic Research Center in cooperation with the Japan Aerospace Exploration Agency concur. Final numbers will come in a few days.

Regardless of whether or not 2011 breaks a record, here’s the important point: Scientists say human-driven climate change continues to help push Arctic sea ice on a disturbing three-decade downward slide.

“Is Arctic ice in a death spiral? Maybe not yet, but it’s in big trouble,” NSIDC director Mark Serreze tells ABC News.

Serreze points out that the five lowest amounts of Arctic sea ice on record (since 1979) have all been recorded in the last five years. And it’s not just the amount of ice, but the quality. It’s also getting thinner, making it more sensitive to increases in temperature.

So why should we care about Arctic sea ice?

-- SEA LEVEL: Scientists tell ABC that Arctic sea ice acts as a giant air conditioner at the top of the planet, helping regulate the planet’s overall temperature. But as the white sea ice (which reflects a portion of the sun’s energy) melts, the darker water underneath absorbs energy, warming the water and creating a “feedback” that in turn, helps melt additional ice in a vicious cycle. Because it is already floating, this does not raise sea level much as it melts.

But in Greenland, it’s a different story. When ice calves off of Greenland’s glaciers, sea level rises. One recent study reported that Greenland glaciers lost 592 square miles of ice between 2000 and 2010. If Greenland melted entirely, global sea levels would rise about 20 feet.

-- WEATHER: Scientists say ice loss may help alter weather patterns across the planet. The jet stream, for example, could shift further north. That could bring more frequent and intense droughts to the U.S. A jet stream change might also affect the path of storms and hurricanes. And more open water and heat could help supercharge those storms.

Many scientists believe human-emitted greenhouse gases warming the planet are already loading the dice toward a future with more weather extremes.

-- WILDLIFE: Melting sea ice also bad news for a number of animals and organisms, including polar bears, who use the ice to hunt for food.

-- OIL AND GAS EXPLORATION: Melting ice literally removes a major barrier to oil and gas exploration in a remote and harsh environment. For years, oil companies and nations have been fighting turf wars over who gets which part of the (potentially very lucrative) sea floor. Exxon, for example, just entered into a new Arctic exploration deal with the Russian government that could be worth tens of billions of dollars.

So what’s causing the ice to melt?

It has been well-established through several peer-reviewed scientific papers that Arctic sea ice loss cannot be explained by natural causes alone. One recent study from the National Center for Atmospheric Research found that roughly half of the Arctic sea ice decline from 1975 to 2005 can be blamed on increasing amounts of greenhouse gases.

Those same researchers were surprised by computer models that predict a 10-year period where the ice melt could pause, and the amount even increase, thanks to natural weather variability that is hard to predict.

The latest thinking among scientists has summer sea ice vanishing from the Arctic well before the end of the century, perhaps within the next 50 years. Given that greenhouse gases are only expected to increase between now and then, scientists do not see a reversal of sea ice declines in the near future.

Copyright 2011 ABC News Radio







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