 |
|
Beyond CO2: Study reveals growing importance of HFCs in climate warming
June 23, 2009Some of the substances that are helping to avert the destruction of the ozone layer could increasingly contribute to climate warming, according to scientists from NOAA's Earth System Research Laboratory and their colleagues in a new study published today in the journal Proceedings of the National Academy of Sciences.
The authors took a fresh look at how the global use of hydrofluorocarbons (HFCs) is expected to grow in coming decades. Using updated usage estimates and looking farther ahead than past projections (to the year 2050), they found that HFCs-especially from developing countries-will become an increasingly larger factor in future climate warming.
"HFCs are good for protecting the ozone layer, but they are not climate friendly," said David W. Fahey, a scientist at NOAA and second author of the new study. "Our research shows that their effect on climate could become significantly larger than we expected, if we continue along a business-as-usual path."
HFCs currently have a climate change contribution that is small (less than 1 percent) in comparison to the contribution of carbon dioxide (CO2) emissions. The authors have shown that by 2050 the HFCs contribution could rise to 7 to 12 percent of what CO2 contributes. And if international efforts succeed in stabilizing CO2 emissions, the relative climate contribution from HFCs would increase further.
HFCs, which do not contain ozone-destroying chlorine or bromine atoms, are used as substitutes for ozone-depleting compounds such as chlorofluorocarbons (CFCs) in such uses as refrigeration, air conditioning, and the production of insulating foams. The Montreal Protocol, a 1987 international agreement, has gradually phased out the use of CFCs and other ozone-depleting substances, leading to the development of long-term replacements such as HFCs.
Though the HFCs do not deplete the ozone layer, they are potent greenhouse gases. Molecule for molecule, all HFCs are more potent warming agents than CO2 and some are thousands of times more effective. HFCs are in the "basket of gases" regulated under the 1997 Kyoto Protocol, an international treaty to reduce emissions of greenhouse gases.
The new study factored in the expected growth in demand for air conditioning, refrigerants, and other technology in developed and developing countries. The Montreal Protocol's gradual phasing out of the consumption of ozone-depleting substances in developing countries after 2012, along with the complete phase-out in developed countries in 2020, are other factors that will lead to increased usage of HFCs and other alternatives.
Decision-makers in Europe and the United States have begun to consider possible steps to limit the potential climate consequences of HFCs. The PNAS study examined several hypothetical scenarios to mitigate HFC consumption. For example, a global consumption limit followed by a 4 percent annual reduction would cause HFC-induced climate forcing to peak in the year 2040 and then begin to decrease before the year 2050.
"While unrestrained growth of HFC use could lead to significant climate implications by 2050, we have shown some examples of global limits that can effectively reduce the HFCs' impact," said John S. Daniel, a NOAA coauthor of the study.
NOAA Headquarters
HFCs currently have a climate change contribution that is small (less than 1 percent) in comparison to the contribution of carbon dioxide (CO2) emissions. The authors have shown that by 2050 the HFCs contribution could rise to 7 to 12 percent of what CO2 contributes. And if international efforts succeed in stabilizing CO2 emissions, the relative climate contribution from HFCs would increase further.
HFCs, which do not contain ozone-destroying chlorine or bromine atoms, are used as substitutes for ozone-depleting compounds such as chlorofluorocarbons (CFCs) in such uses as refrigeration, air conditioning, and the production of insulating foams. The Montreal Protocol, a 1987 international agreement, has gradually phased out the use of CFCs and other ozone-depleting substances, leading to the development of long-term replacements such as HFCs.
Though the HFCs do not deplete the ozone layer, they are potent greenhouse gases. Molecule for molecule, all HFCs are more potent warming agents than CO2 and some are thousands of times more effective. HFCs are in the "basket of gases" regulated under the 1997 Kyoto Protocol, an international treaty to reduce emissions of greenhouse gases.
The new study factored in the expected growth in demand for air conditioning, refrigerants, and other technology in developed and developing countries. The Montreal Protocol's gradual phasing out of the consumption of ozone-depleting substances in developing countries after 2012, along with the complete phase-out in developed countries in 2020, are other factors that will lead to increased usage of HFCs and other alternatives.
Decision-makers in Europe and the United States have begun to consider possible steps to limit the potential climate consequences of HFCs. The PNAS study examined several hypothetical scenarios to mitigate HFC consumption. For example, a global consumption limit followed by a 4 percent annual reduction would cause HFC-induced climate forcing to peak in the year 2040 and then begin to decrease before the year 2050.
"While unrestrained growth of HFC use could lead to significant climate implications by 2050, we have shown some examples of global limits that can effectively reduce the HFCs' impact," said John S. Daniel, a NOAA coauthor of the study.
NOAA Headquarters
Climate Warming Current Events and Climate Warming News RSSPast climate of the northern Antarctic Peninsular informs global warming debate
The seriousness of current global warming is underlined by a reconstruction of climate at Maxwell Bay in the South Shetland Islands of the Antarctic Peninsula over approximately the last 14,000 years, which appears to show that the current warming and widespread loss of glacial ice are unprecedented.
Do dust particles curb climate change?
A knowledge gap exists in the area of climate research: for decades, scientists have been asking themselves whether, and to what extent man-made aerosols, that is, dust particles suspended in the atmosphere, enlarge the cloud cover and thus curb climate warming.
UA scientists seek new emphases in Arctic climate change research
Much of circumpolar Arctic research focuses on the physical, direct changes resulting from climate warming such as sea ice retreat and temperature increases.
Stressed crops emit more methane than thought
Scientists at the University of Calgary have found that methane emission by plants could be a bigger problem in global warming than previously thought.
Iron and biological production in the high-latitude North Atlantic
Southampton scientists have demonstrated an unexpected role of iron in regulating biological production in the high-latitude North Atlantic. Their findings have important implications for our understanding of ocean-climate interactions.
Desert dust alters ecology of Colorado alpine meadows
Accelerated snowmelt--precipitated by desert dust blowing into the mountains--changes how alpine plants respond to seasonal climate cues that regulate their life cycles.
Any way you slice it, warming climate is affecting Cascades snowpack
There has been sharp disagreement in recent years about how much, or even whether, winter snowpack has declined in the Cascade Mountains of Washington and Oregon during the last half-century.
The Agulhas Current, in the southern hemisphere, may influence climate in Europe
Her PhD thesis "Surface and Deep Circulation off South Africa: Agulhas Leakage Influence on the Meridional Overturning Circulation During the Last 345 kyr" presented data on a major ocean current in the southern hemisphere, the Agulhas Current, which transports warm waters from the tropical Indian Ocean to the southern tip of Africa.
Some of Earth's climate troubles should face burial at sea, scientists say
Making bales with 30 percent of global crop residues - the stalks and such left after harvesting - and then sinking the bales into the deep ocean could reduce the build up of global carbon dioxide in the atmosphere by up to 15 percent a year, according to just published calculations.
Emperor Penguins March toward Extinction?
Popularized by the 2005 movie "March of the Penguins," emperor penguins could be headed toward extinction in at least part of their range before the end of the century, according to a paper by Woods Hole Oceanographic Institution (WHOI) researchers published January 26, 2009, in Proceedings of the National Academy of Sciences of the United States of America.
More Climate Warming Current Events and Climate Warming News Articles
 |
Climate Cover-Up: The Crusade to Deny Global Warming by James Hoggan (Author), Richard Littlemore (Contributor) Talk of global warming is nearly inescapable these days — but there are some who believe the concept of climate change is an elaborate hoax. Despite the input of the world’s leading climate scientists, the urgings of politicians, and the outcry of many grassroots activists, many Americans continue to ignore the warning signs of severe climate shifts. How did this happen? Climate Cover-up seeks to answer this question, describing the pollsters and public faces who have crafted careful language to refute the findings of environmental scientists. Exploring the PR techniques, phony "think tanks," and funding used to pervert scientific fact, this book serves as a wake-up call to those who still wish to deny the inconvenient truth. |
 |
Global Warming: A Scientific and Biblical Expose' of Climate Change Starring: Larry Vardiman, Calvin Beisner, Al Gore, Jason Lisle, Michael J. Oard Directed By: Jason Beaupied,Ben Wilt Javier Pena |
 |
An Inconvenient Truth Starring: Al Gore Directed By: Davis Guggenheim |
 |
Crush Global Warming (Male Lead) Ace (Primary Contributor) |
 |
Science Codex Climate And Earth News by Science Codex Science Codex posts articles on the latest science findings from all over the world.Kindle blogs are fully downloaded onto your Kindle so you can read them even when you're not wirelessly connected. And unlike RSS readers which often only provide headlines, blogs on Kindle give you full text content and images, and are updated wirelessly throughout the day. |
 |
Global Warming - Big Book (Climate Change) by Erika Gombatz (Author) What is causing Global Warming? What are the effects? What can we do to stop or reduce Global Warming? We take a critical look from a scientific perspective that will help students separate fact from fiction in popular accounts in order to make informed decisions about products and lifestyle choices that affect the Earth system. We also look at rising sea levels and altered patterns of weather and agriculture which are cited as direct consequences of Global Warming. Finally we look at creative ways to reduce human consumption and output, all in an effort to help clean up our planet. Our ready-to-use resource is written using simplified language and vocabulary which are presented in a way that is easier for students to understand. Comprised of reading passages, student activities, color... |
 |
Snowmen Against Global Warming. Bumper Sticker by Northern Sun Bumper sticker. Reads, "Snowmen Against Global Warming" with picture a melting snowman. |
 |
Global Warming Mug by The Unemployed Philosophers Guild Many scientists and political figures theorize that global warming threatens world ecosystems from the Arctic to the Everglades with rising sea levels and radical climate changes. Ever wonder what that would look like? Wonder no more; simply pour a hot beverage into this mug, and watch Nevada develop a coastline. That's right, while you're sipping you can watch the effects of a 100-meter rise in sea level. Sure to be the most disturbing cup of coffee you've ever had. Mug is microwave safe but is not meant for the dishwasher. |
 |
Stop Global Warming Fridge Magnet by Northern Sun Fridge Magnet. Shaped like a stop sign. Reads, "Stop Global Warming" |
 |
Climate Vest - Small, Tan by Heat Factory This item is so versatile it will keep you cool or warm! It holds 6 reusable cooling packs or 6 large warmers in its six hidden pockets. Vest is made of light weight cotton poly fabric with an adjustable waist drawstring and a front zipper closure. Machine washable. Although most of our products are intended to keep you warm, Heat Factory is concerned for your year-round comfort. Our Cool products help you look cool and stay cool all year long! |
| © 2009 BrightSurf.com |