Scientific American Topic - Global Warming

What will it take to force political action on climate change?

Fri, 06 Nov 2009 17:21:00 EST

As utilities fire up their "clean coal" machines and international negotiators haggle over the precise definition of a tree , only one entity has the courage to stand and deliver the hot air the world so desperately craves on climate change: the U.S. Senate. After a hectic couple of weeks, filled with Republican walkouts and Democratic intransigence, the Senate's Environment and Public Works committee has pushed a bill to the Senate floor that would cut carbon dioxide. [More]

Can Closing the Ozone Hole Also Help Combat Climate Change?

Thu, 05 Nov 2009 16:31:00 EST

Carbon dioxide is the primary greenhouse culprit in human-generated global warming , most scientists agree, but CO 2 itself, and a handful of other substances, are now being promoted as good alternatives to commonly used refrigerants that threaten Earth's atmosphere and climate. [More]

Al Gore advocates for gender equality, political action to slow climate change

Wed, 04 Nov 2009 16:20:00 EST

Slowing climate change is neither inevitable nor impossible, former Vice President Al Gore said in a speech Tuesday night in New York City. Gore, who was launching his new book, Our Choice: A Plan to Solve the Climate Crisis , said that he has "absolute conviction that we have all the tools to solve [several] climate crises." [More]

A Clunker of a Climate Policy

Fri, 30 Oct 2009 08:00:00 EST

The Cash for Clunkers program offers a cautionarytale for the future of climate change control. The federal program paid individuals up to $4,500 to replace their “clunker” automobiles with new, higher-mileage vehicles. Part of the purpose was to give a lift to the ailing auto industry. Another part, at least it was claimed, was to mitigate climate change by getting old high-carbon-emissions vehicles off the road. But billions of dollars were spent quickly without clear answers on what we were getting for our money.

The broad principle of climate change mitigation is to reduce greenhouse gas emissions, including carbon dioxide (CO 2 ) from the combustion of fossil fuels, to target levels at the minimum net cost to society. There are many ways to reduce emissions: drive more efficient or electrically powered vehicles; produce electricity with renewable energy sources; capture CO 2 from power plants and store it geologically; restart the nuclear power sector; weatherproof homes to reduce energy for heating and cooling.... The list is long, with different time horizons, costs and uncertainties.

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Burying Climate Change: Carbon Gets Stuffed Underground

Thu, 29 Oct 2009 08:00:00 EST

Editor's note: The original online version of this story was previously posted.

Over the next five years at least half a million tons of carbon dioxide will be injected into rock deep underneath the Mountaineer power plant near New Haven, W.Va. Although that is less than 0.00001 percent of global emissions of the greenhouse gas and less than 2 percent of the plant’s own CO 2 output, the sequestration, which began in September, marks the first commercial demonstration of the only available technological fix for the carbon problem of coal-fired power plants, one that many coal facilities around the world hope to emulate.

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Novel Analysis Confirms Climate "Hockey Stick" Graph

Wed, 28 Oct 2009 08:00:00 EST

The “hockey stick” graph has been both a linchpin and target in the climate change debate. As a plot of average Northern Hemisphere temperature from two millennia ago to the present, it stays relatively flat until the 20th century, when it rises up sharply, like the blade of an upturned hockey stick. Warming skeptics have long decried how the temperatures were inferred, but a new reconstruction of the past 600 years, using an entirely different method, finds similar results and may help remove lingering doubts.

The hockey stick came to life in 1998 thanks to the work of Michael Mann, now at Pennsylvania State University, and his colleagues (and many other climate scientists who subsequently refined the graph). Reconstructing historical temperatures is difficult: investigators must combine information from tree rings, coral drilling, pinecones, ice cores and other natural records and then convert them to temperatures at specific times and places in the past. Such proxies for temperature can be sparse or incomplete, both geographically and through time. Mann’s method used the overlap, where it exists, of recent proxy data and instrument data (such as from thermometers) to estimate relations between them. It calculates earlier temperatures using a mathematical extrapolation technique [see “ Behind the Hockey Stick ,” by David Appell, Insights; Scientific American, March 2005].

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Contentious Senate Hearings Begin on Climate Bill

Tue, 27 Oct 2009 16:29:00 EST

Senate Finance Chairman Max Baucus said today that he has "serious reservations" about a major global warming bill and warned fellow Democrats to water down the measure in hopes of getting it through the Senate.

Speaking at the start of an Environment and Public Works Committee hearing where he is the second highest-ranking member, the Montana Democrat said he wanted to weaken the bill's 2020 target for greenhouse gas emissions -- now 20 percent below 2005 levels. He did not name a specific midterm target for the heat-trapping gases, instead telling reporters he hoped for "some modification."

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The Future of Climate Policy Could Be Found in Copenhagen

Tue, 27 Oct 2009 09:00:00 EST

In a few short weeks, world leaders will assemble in Copenhagen for the much anticipated United Nations Climate Change Conference. Their goal: to draft an agreement that will limit global warming, chiefly by reducing greenhouse gas emissions. As the 12-day meeting gets closer, the chorus from jaded pundits and politicians gets louder: “It can’t be done.”

Nonsense. The naysayers have two reasonable concerns. One: Countries will never agree on limits because they are out to protect their own interests, which differ. Two: Even if they reach an agreement, it will never hold because it will raise energy prices, which people will resist. Fortunately, both worries can be resolved.

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Climate Change Begins at Home: Small Steps to Cut Greenhouse Emissions Can Lead to Big Results

Mon, 26 Oct 2009 16:01:00 EST

American homes and their energy consumption account for nearly 40 percent of U.S. emissions, 626 million metric tons of carbon in 2005 alone. But 33 simple actions--ranging from improving the insulation to carpooling--could cut those annual carbon emissions by 123 million metric tons. That savings would more than entirely offset emissions from petroleum refineries, iron and steel works, and aluminum smelters combined. [More]

Can a Number Solve the Climate Change Conundrum?

Fri, 23 Oct 2009 15:30:00 EST

Author Bill McKibben never saw this coming. Founder of 350.org, an environmental campaign aimed at holding atmospheric carbon dioxide concentrations below 350 parts per million, McKibben sent word that this Saturday would be the day to take to the streets.

The call went viral in ways far beyond anything McKibben and fellow organizers imagined: As of Thursday morning some 4,317 actions and rallies are planned in 171 countries, with 300 events in China, 1500 across the United States, 500-plus in Central and South America.

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"Albedo Yachts" and Marine Clouds: A Cure for Climate Change?

Wed, 21 Oct 2009 16:00:00 EST

Here's an idea to cool Earth: make marine clouds into better reflectors of sunlight. After all, clouds already reflect more of the sun's radiation back into space than the amount trapped by human emissions of carbon dioxide. So why not make them even more effective? [More]

Geoengineering wars: Another scientist teases out a surprising effect of global deforestation

Mon, 19 Oct 2009 12:44:00 EST

AUSTIN--A new and unpublished analysis of the regional impacts of a hypothetical scheme to mitigate global warming via radical deforestation was unveiled here Sunday at a gathering of science journalists and writers, on the heels of a blogging firestorm about geoengineering and climate change in anticipation of the release of S uperfreakonomics: Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance . [More]

Sunny Germans Triumph in U.S. Solar Decathlon

Fri, 16 Oct 2009 15:00:08 EST

It's all about the meters . As any would-be installer of solar rooftop panels knows, having the right meter to count how much power your photovoltaics are producing is key. So perhaps it's no surprise that Team Germany snatched victory on the last day of the 2009 U.S. Department of Energy's Solar Decathlon with a perfect score in, you guessed it, net metering. [More]

Climate Change May Mean Slower Winds

Thu, 15 Oct 2009 08:00:00 EST

This summer scientists published the first study that comprehensively explored the effect of climate change on wind speeds in the U.S. The report was not encouraging. Three decades’ worth of data seemed to point to a future where global warming lowers wind speeds enough to handicap the nascent wind industry. But the real story, like so much in climate science, is far more complex.

The study of decreased wind speeds came from a team led by Sara Pryor, professor and chair of the atmospheric science program at Indiana University. It examined wind speed data from hundreds of locations across the U.S. The team attempted to correct for any change in instrument position (such as what would happen if an airport places its anemometer atop a new control tower) and calculated for each site the average annual wind speed. Pryor and her colleagues found that in most of the U.S. wind speeds appear to be waning, in many locations by more than 1 percent a year.

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Just How Sensitive Is Earth's Climate to Atmospheric Carbon Dioxide?

Thu, 08 Oct 2009 19:20:00 EST

Carbon dioxide levels climbing toward a doubling of the 280 parts per million (ppm) concentration found in the preindustrial atmosphere pose the question: What impact will this increased greenhouse gas load have on the climate? If relatively small changes in CO 2 levels have big effects--meaning that we live in a more sensitive climate system--the planet could warm by as much as 6 degrees Celsius on average with attendant results such as changed weather patterns and sea-level rise. A less sensitive climate system would mean average warming of less than 2 degrees C and, therefore, fewer ramifications from global warming. [More]

Solar Decathlon Promotes Sunnier Future

Thu, 08 Oct 2009 13:00:08 EST

[ Below is the original script. But a few changes may have been made during the recording of this audio podcast. ]

Homes are rising on the National Mall in Washington, D.C. No, it's not a return of Hoovervilles thanks to the Great Recession. These are solar homes competing in the U.S. Department of Energy's Solar Decathlon , which starts October 8.

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Climate Change Equals Culture Change in the Andes

Mon, 05 Oct 2009 17:03:00 EST

MAHUAYANI, Peru--A full moon hangs in the frosty sky as hundreds of dancers file in darkness toward the top of the Sinakara valley high in the Andes. Footsteps crunch frozen tundra, and dancing shoes step gingerly over ice-covered rivulets. Musicians blow on numb fingers as sunlight tips the hills to the west and creeps up the valley. [More]

U.S. Senate to Consider U.S. Climate Legislation

Wed, 30 Sep 2009 16:54:00 EST

Sens. John Kerry (D-Mass.) and Barbara Boxer (D-Calif.) and nine Senate supporters kicked off the autumn global warming debate today with a campaign-style rally releasing their comprehensive climate bill .

"We know clean energy is the ticket to strong, sustainable economic growth," Boxer, the chairwoman of the Environment and Public Works Committee , said at the Capitol Hill event, in front of a large American flag and three dozen or so military veterans, business leaders and environmentalists.

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Farmed Out: How Will Climate Change Impact World Food Supplies?

Wed, 30 Sep 2009 09:30:00 EST

The people of East Africa once again face a devastating drought this year: Crops wither and fail from Kenya to Ethiopia, livestock drop dead and famine spreads. Although, historically, such droughts are not uncommon in this region, their frequency seems to have increased in recent years, raising prices for staple foods, such as maize. [More]

What Will U.S. Climate Legislation Look Like?

Tue, 29 Sep 2009 19:24:00 EST

An early version of Senate climate legislation obtained today by E&E confirms that Sens. Barbara Boxer (D-Calif.) and John Kerry (D-Mass.) largely plan to follow the path their Democratic colleagues pursued in the House-passed climate bill.

But the 684-page Senate draft bill diverges from the House measure in its push for a 2020 emissions target of 20 percent, compared with the House's bill's 17 percent limit.

[More]