|
About | Contact | Mongabay on Facebook | Mongabay on Twitter | Subscribe |
|
|
Global warming may be worse than predicted mongabay.com May 22, 2006 Climate change estimates for the next century may have substantially underestimated the potential magnitude of global warming says a new study from a team of European scientists. The paper, published in the May 26 issue of Geophysical Research Letters, says that warming may be 15-to-78 percent higher than estimates that do not consider the feedback mechanism involving carbon dioxide and Earth's temperature. Greenhouse gas/temperature feedback mechanism may raise warming beyond previous estimates American Geophysical Union Release In a paper to be published on 26 May in Geophysical Research Letters, Marten Scheffer of Wageningen University in the Netherlands and colleagues at the Potsdam Institute for Climate Impact Research in Germany and the Centre for Ecology and Hydrology in the United Kingdom use newly acquired ancient climate data to quantify the two-way phenomenon by which greenhouse gases not only contribute to higher temperatures, but are themselves increased by the higher temperatures. This higher concentration leads to still higher temperatures, in what scientists call a positive feedback loop. The researchers achieved their breakthrough by interpreting the high-resolution data from polar ice cores and temperature reconstructions based on geological proxy data in a new way. Although the effect of greenhouse gases on temperature is well known, the reverse effect is usually ignored. The latter has now been estimated through a correction of the past climate data, using a model of the greenhouse effect.
Therefore, the authors focused especially on relatively recent climatic anomaly known as the "Little Ice Age." During this period (about 1550-1850), immortalized in many paintings of frozen landscapes in Northern Europe, Earth was substantially colder than it is now. This, scientists have concluded, was due largely to reduced solar activity, and just as during true ice ages, the atmospheric carbon level dropped during the Little Ice Age. The authors used this information to estimate how sensitive the carbon dioxide concentration is to temperature, which allowed them to calculate how much the climate-carbon dioxide feedbacks will affect future global warming. As Marten Scheffer explains, "Although there are still significant uncertainties, our simple data-based approach is consistent with the latest climate-carbon cycle models, which suggest that global warming will be accelerated by the effects of climate change on the rate of carbon dioxide increase. In view of our findings, estimates of future warming that ignore these effects may have to be raised by about 50 percent. We have, in fact, been conservative on several points. For instance, we do not account for the greenhouse effect of methane, which is also known to increase in warm periods." RELATED ARTICLES Global warming to be more moderate than some expect April 19, 2006 A new study published in Nature says that climate change will be more moderate than some recent projections. Nevertheless, says lead author Gabriele C. Hegerl of Duke University, we can expect significant changes in the future. "This still commits us to quite a bit of climate change, but it leaves the door open to avoiding the largest and most devastating consequences," Dr. Hegerl told the Washington Post. The study looked to refine "climate sensitivity", or the change in global mean surface temperature in response to a doubling of atmospheric carbon dioxide levels. In 2001, the Intergovernmental Panel on Climate Change (IPCC) estimated that this value would likely fall in the range of 1.5 to 4.5 degrees Celsius (2.7-8°F), but other groups have projected much broader ranges. Currently carbon dioxide levels stand at 381 parts-per-million (ppm) or about 36 percent higher than pre-industrial levels. The IPPC projects that projects that atmospheric carbon dioxide levels could reach 450-550 ppm by 2050. Slowing global warming may be less costly than initially thought March 9, 2006 Preventing carbon dioxide levels from rising to potentially dangerous levels could cost less far less than originally projected—less 1 percent of gross world product as of 2050—but a major shift in the way energy is found, transformed, transported and used will be necessary to prevent a severe energy crisis within the next century, say researchers from the The Earth Institute. In a report published in the most recent issue of Brookings Papers on Economic Activity, Klaus S. Lackner and Jeffrey D. Sachs of The Earth Institute argue that significant technological developments will be required to meet future energy needs and stave off potential cataclysmic effects of climate change. This article includes a modified news release from the American Geophysical Union.
Tags: climate science climate change earth science Climate Modeling green News index | RSS | News Feed | Twitter | Home Advertisements: Organic Apparel from Patagonia | Insect-repelling clothing
|
WEEKLY NEWSLETTER 
Photos HIGH RESOLUTION PHOTOS / PRINTS 
CALENDARS 
CANVAS BAGS 
|
||||||||||||||||||||||||||||||
|
Copyright mongabay 2010 Carbon dioxide (CO2) emissions generated from mongabay.com operations (server, data transfer, travel) are mitigated through an association with Anthrotect, an organization working with Afro-indigenous and Embera communities to protect forests in Colombia's Darien region. Anthrotect is protecting the habitat of mongabay's mascot: the scale-crested pygmy tyrant. |
