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Monday, October 24, 2011

Window Closing to Prevent Hotter, Stormier Planet Earth

CommonDreams.org

by Stephen Leahy

CHANGWON, South Korea - The window to limit global warming to less than two degrees C is closing so fast it can be measured in months, a new scientific analysis revealed Sunday.

The International Energy Agency estimates that 80 percent of projected emissions from the power sector in 2020 are already locked in. (Credit:U.S. EPA/creative commons) Without putting the brakes on carbon emissions very soon, large parts of Africa, most of Russia and northern China will be two degrees C warmer in less than 10 years. Canada and Alaska will soon follow, the regional study shows.

"If one is sincerely committed to limit global temperature increase to below two degrees C... (governments) committing to a global peak emission level and peak year makes sense from a science perspective," said Joeri Rogelj of the Institute for Atmospheric and Climate Science in Zurich, who headed the analysis published Sunday in the journal Nature Climate Change.

Governments will be meeting in Durban, South Africa starting Nov. 28 to launch the next round of climate treaty negotiations, which so far have failed to ensure their goal of less than a two-degree C increase will be achieved.

IPS asked Rogelj if government delegates in Durban ought to set a specific year by which global emissions will peak and then decline to ensure the two-degree C target will be met.

"Committing to such targets would ensure that we embark globally on a technologically and economically feasible low-emission path," Rogelj said.

Rogelj and a group of leading experts show in this state-of-the-art analysis that to have a 66-percent or better probability of staying below two degrees C this century, global carbon emissions must peak before 2020. Global emissions ought to be around 44 billion tonnes of CO2 in 2020. That is four billion tonnes (also called gigatonnes, Gt) less than the estimated emissions for 2010.

After 2020 emissions must decline rapidly, about two to three percent less each year until they fall to 20 Gt by 2050, according to the computer models. This is an emissions "pathway that will be very challenging to achieve", Rogelj and colleagues conclude in their study.

"Very challenging" is scientist-talk for something that will be extremely difficult to do. The International Energy Agency (IEA) estimated that 80 percent of projected emissions from the power sector in 2020 are already locked in, as they will come from power plants that are currently in place or under construction today.

"This significant increase in CO2 emissions and the locking in of future emissions due to infrastructure investments represent a serious setback to our hopes of limiting the global rise in temperature to no more than two degrees C," said Dr. Fatih Birol, chief economist of the IEA, last May.

The heating of the planet from burning fossil fuels is uneven since 70 percent of the planet is water, and most of that is cold water. For various reasons, the Arctic, Canada, Eurasia and parts of Africa are warming faster and will be substantially warmer now and in the coming decades. It also important to understand that returning the planet to pre-global warming temperatures is very unlikely.

Another new re-analysis also published in Nature Climate Change Sunday puts some dates on when much of the Northern Hemisphere and parts of Africa will cross the two degrees of warming threshold. Without major emission reductions, the African Sahel, including the Horn of Africa, along with northern Eurasia and the Arctic will cross that threshold very soon - between 2020 and 2030 - according to a study led by Manoj Joshi of the University of Reading in the United Kingdom.

They also found that by the time a child born today reaches 50 years old, it will be at least two degrees warmer everywhere except the oceans.

Even if carbon emissions cannot be cut fast enough to avoid two degrees C of warming in some parts of the world, urgent action will buy those regions valuable time - a decade or two - so they will have time to adapt, assuming they can.

Although two degrees C seems like a small amount, it is akin to a person running a high fever, with all kinds of consequences for the human body. On planet Earth, that amount of warming has serious consequences for food, water and biodiversity. It will guarantee more and stronger extreme weather events, including droughts and flooding.

Two degrees C puts humanity on a new hotter, stormier planet that is less compatible with human survival.

As for staying below 1.5 degrees C, as African nations, Pacific Island states and others believe is essential for survival, it may already be too late. In all the 193 scenarios examined by Rogelj et al, there were only two that suggest is it possible to stay below 1.5 C during this century. And that includes heavy use of bioenergy with carbon capture and sequestration.

More extreme measures, such as a technical study called The Energy Report by Ecofys, a leading energy consultancy in the Netherlands that developed a plan to shift the world to 100-percent renewable energy by 2050, were not included, said Rogelj.

"The [two] scenarios we analyse indicate it would be technologically and economically possible to follow such a future path (1.5 degrees C). They do not take into account the fact that there could be political and societal barriers," he said.

The two-degree C window, not to mention the 1.5 C window, is closing faster than most realise. There are less than 100 months left for governments, industry and the public to reduce global emissions by at least four Gt. It will be very difficult but it can be done, Rogelj et al note in their study.

Starting sooner is far easier than later. The Durban climate talks may be the last chance for governments to do what is necessary to keep their promise of less than two degrees.

The Rogelj study concludes with an uncharacteristically blunt warning to governments and the public.

"Without a firm commitment to put in place mechanisms to enable an early global emissions peak followed by steep reductions thereafter, there are significant risks that the two degrees C target, endorsed by so many nations, is already slipping out of reach."

Saturday, October 22, 2011

New study confirms reality of global warming

New study confirms reality of global warming

By Muriel Kane
Friday, October 21, 2011

stop-global-warming-wikimedia

A broad-based new study of climate change has confirmed earlier evidence of a global rise in average land temperatures of 1 degree Centigrade since the 1950′s. However, it draws no conclusions as to whether this warming is man-made.

The Berkeley Earth Surface Temperature study, released on Thursday, analyzed data from fifteen different sources, some going back more than two centuries, to answer doubts raised by climate change skeptics in response to earlier studies.

Previous studies had been able to rule out certain sources of possible error, including the urban heat island effect and poor station quality, but they had been based on a limited number of data sources, and skeptics had continued to claim that the results might have been skewed as a result. The new study, which includes almost all available data, is intended to counter that claim.

The preliminary results of the study, along with the entire database and other materials, are publicly available at the Berkeley Earth website.

According to the project’s founder, Professor Richard A. Muller, “Our biggest surprise was that the new results agreed so closely with the warming values published previously by other teams in the U.S. and the U.K. This confirms that these studies were done carefully and that potential biases identified by climate change skeptics did not seriously affect their conclusions.”

Project co-founder Elizabeth Muller added that she hopes the study will “cool the debate over global warming by addressing many of the valid concerns of the skeptics in a clear and rigorous way.”

The authors of the study point out that although 2/3 of the sites examined showed warming, another 1/3 — including much of the United States and northern Europe — had experienced cooling over the past 70 years, and they suggest that this could be responsible for widespread climate skepticism in those regions.

Photo by AgnosticPreachersKid (Own work) [CC-BY-SA-3.0 (www.creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons.

Muriel Kane
Muriel Kane

Muriel Kane is an associate editor at Raw Story. She joined Raw Story as a researcher in 2005, with a particular focus on the Jack Abramoff affair and other Bush administration scandals. She worked extensively with former investigative news managing editor Larisa Alexandrovna, with whom she has co-written numerous articles in addition to her own work. Prior to her association with Raw Story, she spent many years as an independent researcher and writer with a particular focus on history, literature, and contemporary social and political attitudes. Follow her on Twitter at @Muriel_Kane

Monday, October 17, 2011

Trees have a tipping point




Amount of forest cover can shift suddenly and unexpectedly

Web edition : Thursday, October 13th, 2011


access

Fires like this one in South Africa burn rapidly and regularly through savanna ecosystems, a process that allows grasslands to remain open and helps prevent trees from establishing themselves.


Like Coke versus Pepsi, tropical land ecosystems come in two choices: forest or grassland. New research shows these two options can switch abruptly, and there’s rarely any in-between.

If so, then many of these ecosystems are particularly vulnerable to future changes such as rising temperature, scientists say. With just slight shifts in rainfall or other factors, people living in what is now tropical rainforest might suddenly find themselves in scrubland populated by a different mix of plants and animals — where people’s livelihoods might have to change dramatically.

“That transition is not going to happen smoothly,” says Milena Holmgren, an ecologist at Wageningen University in the Netherlands. “The evidence is showing there are these big jumps.”

Holmgren and her colleagues describe the finding in the Oct. 14 Science. Another group, from Princeton University and South Africa’s national research council, report similar conclusions in a second paper in the same journal.

In theory, the relationship between rainfall and tree cover should be straightforward: The more rain a place has, the more trees that will grow there. But small studies have suggested that changes can occur in discrete steps. Add more rain to a grassy savanna, and it stays a savanna with the same percentage of tree cover for quite some time. Then, at some crucial amount of extra rainfall, the savanna suddenly switches to a full-fledged forest.

But no one knew whether such rapid transformations happened on a global scale. Separately, both research groups decided to look at data gathered by the MODIS instruments on board NASA’s Terra and Aqua satellites, which sense vegetation cover and other features of the land surface. This information included how much of each square kilometer of land was covered by trees, grasses or other vegetation. Both teams focused on the tropics and subtropics of Africa, South America and Australia, because those areas are thought to be least disturbed by human activity.

Looking at the numbers, Holmgren’s group identified three distinct ecosystem types: forest, savanna, and a treeless state. Forests typically had 80 percent tree cover, while savannas had 20 percent trees and the “treeless” about 5 percent or less. Intermediate states — with, say, 60 percent tree cover — are extremely rare, Holmgren says. Which category a particular landscape fell into depended heavily on rainfall.

Fire may be another important factor in determining tree cover, as the second group found. Led by Princeton ecology graduate student Carla Staver, this team studied how fire helped differentiate between forest and savanna. Fire spreads quickly in savannas because of all the grasses and slowly in tree-dense forests. “There’s a tipping point between where you get fires spreading easily and where you don’t,” Staver says.

That point, she and her colleagues found, sits at a tree cover of about 40 to 45 percent. Below that number, fires spread easily and prevent new trees from establishing themselves. Above that number, trees work to maintain a thick canopy that acts as a barrier to stop fire from spreading.

“These two papers tell us that these feedbacks really do operate at all scales,” says Audrey Mayer, an ecologist at Michigan Technological University in Houghton. “They’ll make us have to redo some of our assumptions about how things are going to change in the future.”

Many global climate models, for instance, assume a smooth transition between savanna and forest as temperature and rainfall change. But the new work suggests that forests could appear or disappear quickly, Mayer says, especially if people complicate the picture. “You can’t just plant a couple of trees and they’ll grow up and the forest will come back,” she says. “You have to fight those internal feedbacks.”

Staver and her colleagues are now searching for savanna-forest transitions that are occurring right now. “These things are definitely happening,” she says, “and the new work tells us it could be even more widespread than we’d thought.” Studying where landscapes are changing could help the scientists better understand what causes ecosystems to tip from one category to the other.

For their part, the Dutch scientists have developed “resilience maps” that show which places are most likely to tip from savanna to forest or vice versa. Farmers scratching out a living in western Africa or ranchers running cattle on the fringes of the Amazon might use such maps to learn how viable their livelihoods are likely to be in coming decades.

Locals could thus spend more time and energy working to keep the ecosystem the way it is, perhaps by building extra capacity for storing water or by cutting back on logging. Or residents could cut down more trees to tip a forest into a grassy rangeland for their animals. “These maps can be a tremendous tool for all kinds of organizations,” Holmgren says.

Mayer says she’d like to see the analysis extended into the Northern Hemisphere, where she suspects the results might be the same. Across parts of Illinois and Indiana, for instance, stretches a narrow strip of tallgrass prairie surrounded by forests dubbed the “prairie peninsula.” The peninsula was probably kept grassy by centuries of fire and grazing management — because otherwise it, too, would revert to forest.


Thursday, October 13, 2011

Winter 2011-2012: Brutal for the Midwest, Great Lakes

By , Meteorologist
Oct 11, 2011; 7:53 AM ET

Hands down, AccuWeather.com's long-range experts agree that the Midwest and Great Lakes region will be dealt the worst of winter this year.

In terms of both snow and cold, this winter is expected to be the worst in Chicago.

AccuWeather.com Long-Range Meteorologist Josh Nagelberg even went so far as to say, "People in Chicago are going to want to move after this winter."

However, for the worst of winter's cold alone, the AccuWeather.com Long-Range Forecasting Team points to Minneapolis.

The team also highlights Buffalo, N.Y., Indianapolis and Omaha, Neb., as cities that will have to deal with a hefty amount of snow.

Bitterly cold blasts of arctic air are expected to invade the northern Plains, Midwest and Great Lakes December through January, while snowfall averages above normal. "A couple of heavy hitters are possible [during this time]," Pastelok said in relation to the snow.

Snowfall is predicted to be above normal from Minnesota and Iowa into Michigan, Ohio and parts of West Virginia and Kentucky. Above-normal snowfall is also likely in areas farther east into Pennsylvania and New York due to a lake-effect snow season.

This buildup of snow cover across the Midwest and Great Lakes could act to prolong the colder-than-normal weather beyond February and into early spring.

Full AccuWeather.com Winter 2011-2012 Forecast



Brutal Winter Predicted for U.S.

Scientific American


AccuWeather | More Science

Brutal Winter Predicted for U.S.

Another La Nina in the Pacific Ocean will make it a cold and snowy winter in most parts of the country

| October 6, 2011

Image: AccuWeather.com

The AccuWeather.com Long-Range Forecasting Team is predicting another brutally cold and snowy winter for a large part of the country, thanks in large part to La Niña... yet again.

La Niña, a phenomenon that occurs when sea surface temperatures across the equatorial central and eastern Pacific are below normal, is what made last year's winter so awful for the Midwest and Northeast. Monster blizzards virtually shut down the cities of New York and Chicago. Last winter was one of New York City's snowiest on record.

La Niñas often produce a volatile weather pattern for the Midwest and Northeast during winter due to the influence they have on the jet stream. The graphic below shows the position the jet stream typically takes over the U.S. during La Niña.

This graphic illustrates the common position the jet stream takes over the United States during La Niña.

The way the jet stream is expected to be positioned during this winter's La Niña will tend to drive storms through the Midwest and Great Lakes. Last year, the jet stream steered storms farther east along the Northeast coast, hammering the Interstate 95 corridor.

Therefore, instead of New York City enduring the worst of winter this year, it will likely be Chicago.

"The brunt of the winter season, especially when dealing with cold, will be over the north-central U.S.," stated Paul Pastelok, expert long-range meteorologist and leader of the AccuWeather.com Long-Range Forecasting Team.

Chicago, which endured a monster blizzard last winter, could be one of the hardest-hit cities in terms of both snow and cold in the winter ahead.

AccuWeather.com Long-Range Meteorologist Josh Nagelberg even went so far as to say, "People in Chicago are going to want to move after this winter."

While winter's worst may not be focused over the major cities of the Northeast this year, the region will not get by unscathed. Pastelok warns there could be a few significant snow and ice storms that could pack a punch.

Ice events could also be a problem for areas farther south from the southern Plains to the southern Appalachians this season, while a significant severe weather threat develops in the Lower Mississippi Valley in February. This threat is extremely concerning for the areas in Mississippi and Alabama that were devastated by tornadoes in the spring.

The West is expected to be split between mild and dry conditions in the Southwest and highly-variable, frequently-changing weather elsewhere.

Chances that Texas pulls out of its epic drought this winter are extremely slim with below-normal precipitation predicted for a large portion of the state.

Brutal Winter Ahead for the Midwest, Great Lakes
Hands down, AccuWeather.com's long-range experts agree that the Midwest and Great Lakes region will be dealt the worst of winter this year.

Bitterly cold blasts of arctic air are expected to invade the northern Plains, Midwest and Great Lakes December through January, while snowfall averages above normal. "A couple of heavy hitters are possible [during this time]," Pastelok said in relation to the snow.

In terms of both snow and cold, this winter is expected to be the worst in Chicago.

Full Winter Forecast for the Midwest and Great Lakes

More Monster Snowstorms for the Northeast This Winter?
Overall, this winter is not expected to be as extreme as last winter for the Northeast's major cities. However, there could still be a few snow or ice storms that have a significant impact.

Snowfall is forecast to average near or even slightly above normal in areas south and east of the mountains from Virginia to Maine.

For areas north and west of the Appalachians, however, snowfall for the season is expected to be much higher. An early, heavy lake-effect snow season will put northwestern Pennsylvania and western New York into the zone of winter's worst snow and cold, according to the team.

Full Winter Forecast for the Northeast

Ice Zone Sets Up Across Southern States; Severe Threat Develops in February
The Long-Range Team expects areas from northeastern Texas and Oklahoma into Kentucky and Tennessee to deal with more ice than snow events this winter, especially from early to mid-season.

Occasionally, icing could affect areas farther east into the western Carolinas and northern parts of Alabama and Georgia. This would be most likely in January.

The team also expects a significant risk for severe weather and flood events to develop over the lower Mississippi Valley in February. Mississippi, Alabama and Tennessee, which were devastated by tornadoes in the spring, will be extremely sensitive to any severe weather outbreaks.

Full Winter Forecast for the Southeast

Southwest, Texas Stay Parched and Warmer than Normal
"Mild and dry" will unfortunately be the mantra this winter for much of Texas and the Southwest, a region that desperately needs rain. Texas continues to suffer through the worst drought in its history.

Precipitation is expected to remain below normal in southern and western Texas and the interior Southwest this season. "The interior Southwest will be the driest area of the country through winter," Pastelok said.

Northern and eastern Texas, however, could fair a bit better with higher chances for precipitation as cold fronts "make it there with ease", as Pastelok stated. The downside to these higher precipitation chances, however, will be the risk of ice events, especially from late December into January.

Full Winter Forecast for the Southwest, Texas and Southern Plains

West to Experience Big Swings This Winter
Apart from the Southwest, people across the western U.S. can expect large swings in weather conditions this winter, according to the Long-Range Team.

December is likely to feature above-normal warmth across much of the entire West. However, from late December into January, the team expects a transition where cold fronts will drop farther south along the West Coast, reaching northern and central California. This transition should bring temperatures back near normal, away from the interior Southwest.

The famed "Pineapple Express", a phenomenon that occurs when a strong, persistent flow of tropical moisture sets up from the Hawaiian Islands to the West Coast of the U.S., could develop for a time this winter. This phenomenon often leads to excessive rain and incredible snow events.

Full Winter Forecast for the West

The AccuWeather.com 2011-2012 Winter Forecast runs in line with meteorological winter, which begins on Dec. 1 and runs through the end of February. Astronomical winter, on the other hand, begins on Dec. 22 this year and runs through March 20.

From AccuWeather.com (find the original story here); reprinted with permission.