ScienceDaily (Mar. 28, 2003) — CHAMPAIGN, Ill. -- Uncertainty in the climate sensitivity to growing levels of atmospheric carbon dioxide has been a stumbling block to policy makers addressing the climate change issue. A study published in the March 28 issue of the journal Science, however, concludes that huge reductions in fossil-fuel carbon emissions will be required by the middle of this century -- regardless of the likely climate sensitivity.

"To reduce carbon dioxide emissions and avoid dangerous interference with the climate system, we must switch to alternative, carbon-free energy sources," said Atul Jain, a professor of atmospheric sciences at the University of Illinois at Urbana-Champaign and a co-author of the study.

Jain and his colleagues -- lead author Ken Caldeira, a senior scientist at the Lawrence Livermore National Laboratory, and Martin Hoffert, a professor of physics at New York University -- found that even if climate sensitivity is in the low end of the accepted range, climate stabilization will require a massive transition to carbon-emission-free energy technologies during this century.

Climate sensitivity is the global mean temperature change that would result from doubling the amount of carbon dioxide in the atmosphere. Based on current models, climate sensitivity is thought to lie between 1.5 degrees Celsius and 4.5 degrees Celsius.

In their study, which was funded by the U.S. Department of Energy, the researchers constructed stabilization pathways that led to a 2 degree Celsius warming after the year 2150. For each of the pathways, they calculated the allowable carbon dioxide levels using a globally aggregated Earth system model called the Integrated Science Assessment Model.

If climate sensitivity is at the high end of the range, then by the end of this century nearly all of our power will have to come from non-carbon-dioxide-emitting sources, the researchers found. "We must begin replacing fossil fuels with alternative energy technologies that support economic growth and equity," Jain said. "To achieve stabilization at a 2 degree Celsius warming, we would need to bring the equivalent of a large carbon-emission-free power plant into production somewhere in the world every day for the next 50 years."

The study concludes: "We do not now have non-carbon-dioxide-emitting energy technologies that can be applied today at the required scale. Given the long lead times needed for market penetration of new energy technologies, we need to develop appropriate energy technologies now."

Story Source:

Adapted from materials provided by University Of Illinois At Urbana-Champaign.

Related Stories

Whatever The Warming, Ocean Acidifies From Carbon-Dioxide Buildup (Mar. 27, 2007) — A new study indicates that future changes in ocean acidification caused by atmospheric carbon dioxide emissions are largely independent of the amount of climate change caused by those ...  > read more

Carbon Emissions Linked To Global Warming In Simple Linear Relationship (June 11, 2009) — Scientists have found a direct relationship between carbon dioxide emissions and global warming. Researchers used a combination of global climate models and historical climate data to show that there ...  > read more

Don't Count On Long-Term Success In Climate Policy, Warns Paper In Decision Analysis (July 6, 2008) — Long-term climate change policy in the US and abroad is likely to change very slowly, warns a researcher who calls for stronger short-term goals to reduce carbon emissions. Although staging climate ...  > read more

First-Ever 'State Of The Carbon Cycle Report' Finds Troubling Imbalance (Nov. 17, 2007) — The first "State of the Carbon Cycle Report" for North America finds the continent's carbon budget increasingly overwhelmed by human-caused emissions. North American sources release nearly 2 billion ...  > read more

Like It Or Not, Uncertainty And Climate Change Go Hand-in-Hand (Oct. 27, 2007) — Despite decades of research, it appears the more likely it is that conditions will cause climate to warm the more uncertainty exists about how much warming will actually take place. Despite decades ...  > read more

Search ScienceDaily

Our Changing Climate