Extreme winter weather linked to climate change

WASHINGTON Tue Mar 1, 2011 11:07pm EST

Pedestrians walk on the streets of Chicago after a major snowstorm February 2, 2011. REUTERS/John Gress

Pedestrians walk on the streets of Chicago after a major snowstorm February 2, 2011.

Credit: Reuters/John Gress

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WASHINGTON (Reuters) - This winter's heavy snowfalls and other extreme storms could well be related to increased moisture in the air due to global climate change, a panel of scientists said on Tuesday.

This extra moisture is likely to bring on extraordinary flooding with the onset of spring in the Northern Hemisphere, as deep snowpack melts and expected heavy rains add to seasonal run-off, the scientists said in a telephone briefing.

As the planet warms up, more water from the oceans is evaporated into the atmosphere, said Todd Sanford, a climate scientist at the Union of Concerned Scientists. At the same time, because the atmosphere is warmer, it can hold onto more of the moisture that it takes in.

Intense storms are often the result when the atmosphere reaches its saturation point, Sanford said.

This year, a series of heavy storms over the U.S. Midwest to the Northeast have dropped up to 400 percent of average snows in some locations, said Jeff Masters, director of meteorology at Weather Underground.

The amount of water in that snowpack is among the highest on record, Masters said.

"If you were to take all that water and melt it, it would come out to more than 6 inches over large swaths of the area," Masters said. "If all that water gets unleashed in a hurry, in a sudden warming, and some heavy rains in the area, we could be looking at record flooding along the Upper Mississippi River and the Red River in North Dakota."

That tallies with projections by the U.S. National Weather Service, which last month said a large stretch of the north central United States is at risk of moderate to major flooding this spring.

SPRING CREEP

Spring floods could be exacerbated by spring creep, a phenomenon where spring begins earlier than previously.

"We've documented in the mountains of the U.S. West that the spring runoff pulse now comes between one and three weeks earlier than it used to 60 years ago," Masters said. "And that's because of warmer temperatures tending to melt that snowpack earlier and earlier."

In the last century, global average temperatures have risen by 1.4 degrees Fahrenheit (.8 Celsius). Last year tied for the warmest in the modern record. One place this warmth showed up was in the Arctic, which is a major weather-maker for the Northern Hemisphere, according to Mark Serreze, director of the U.S. National Snow and Ice Data Center.

One driver of this winter's "crazy weather," Serreze said, is an atmospheric pattern known as the Arctic Oscillation, which has moved into what climate scientists call a negative phase.

This phase means there is high pressure over the Arctic and low pressure at mid-latitudes, which makes the Arctic zone relatively warm, but spills cold Arctic air southward to places like the U.S. Midwest and Northeast.

This negative Arctic Oscillation has been evident for two years in a row, the same two winters that have had extreme storms and heavy snowfalls.

It is possible, but not certain, that the negative Arctic Oscillation is linked to warming of the Arctic, which is in turn influenced by a decrease in sea ice cover throughout the region.

The only underlying explanation for these events is climate warming due to heightened greenhouse gas levels, Serreze said.

(Editing by Mohammad Zargham)

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Comments (9)
Iokarlo wrote:
Recently, the NASA-WISE Telescope have discovered at the very neighbourhood of thje Solar System is what appears as a brown dwarf star… The one which is the companion star of the binary system our Sun is part of… And such a companion has a mass biger than Jupiter and is named “Tyche”… I ask any body who whould answer: Could it be that “Tyche” is pulling the Solar System planet orbits and the nowadays so called “Cilmate change” we are experimenting is mainly an effect of the aforementioned “Orbits change”?

Mar 02, 2011 5:42am EST  --  Report as abuse
Iokarlo wrote:
Recently, the NASA WISE infrared telescope have discovered at the very neighbourhood of our Solar System, wich appears as a brown dwarf and it is the predicted companion star of the binary system formed by the Sun and the former… Such a companion, now named “Tyche”, has a mass greater than Jupiter; wich is, in terms of gravitational pulling, a continuous pull to be taken in account… Now, I want to ask to any body who whould answer: Could it be that such a mass is an accountable astrophysic force, wich is modifying the Solar System planetary orbits; and in such a case, could the planetary orbits change be the main cause for the nowadays so called “climate change” (i.e: The Earth orbit is becoming more elongated and the elliptical segment corresponding to winter is going close to the Sun, as its opposite, the summer segment is going far of?

Mar 02, 2011 6:08am EST  --  Report as abuse
bsbailey wrote:
It had to happen – now they are blaming our recent cold winter on global warming. When will people realize that the Earth and its climate will do as it has done since long before humans existed, and will continue to do so long after we’re gone, regardless of our tampering? While we do have some impact, it’s insignificant when compared to other forces well beyond our control. We know the planet was warmer in the Dark Ages than it is now, and that was long before fossile fuels were used. We know that the planet went through a “Little Ice Age” that lasted approximately 500 years, starting in the Middle Ages, and that brief cooling period led to mass crop failures and famine in Europe. We know that the planet was much warmer 120,000 years ago, at the peak of the last inter-glacial period. The last major ice age officially ended about 9000 years ago and we are climbing into the current interglacial period, so we should be seeing a general warming trend that most likely will last for several thousands of years, until we peak and start sliding into the next ice age. The sun and changes in the Earth’s orbit have a much greater impact on our climate than any of Man’s exploits. We should focus on reducing pollution for the sake of having a cleaner world and stop with the red herring of global warming, which is nothing but a political scare tactic.

Mar 02, 2011 8:33am EST  --  Report as abuse
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