Plants' role in global warming re-examined in ORNL Science paper

May 01, 2006

OAK RIDGE, Tenn., May 1, 2006 -- Estimates of increased plant respiration in response to higher global temperatures may be somewhat overstated as they have not taken into account plants' ability to adjust to changing conditions, according to researchers from Oak Ridge National Laboratory.

In a Perspectives paper published April 28 by Science, a team led by Tony King cites ORNL findings suggesting that about 9 percent more carbon will be stored in plants and soil with the acclimation of plants included in the model. While this amount is relatively small compared to different climate-carbon simulations performed over the years, the authors note that this acclimation phenomenon should not be ignored.

"This is carbon that might otherwise be released to the atmosphere as carbon dioxide and could further influence future climate change," said King, a researcher in ORNL's Environmental Sciences Division. "Our ability to accurately predict global change over the next several decades depends upon having a thorough understanding of multiple interacting factors, including plant respiration.

"The fact is that plants adapt to higher temperatures and their levels of respiration adjust downward."

While some previous climate-carbon simulations have included differentiation among vegetation types, none have incorporated an explicit time-dependent acclimation of plant respiration to increasing temperatures. ORNL researchers also looked at the influence of temperature acclimation at both the local ecosystem and global scales.

ORNL's study looked at the period from 1930 to 2100, with and without acclimation of leaf respiration.

"All other things being equal, as they are in our simulations, more carbon stored in plants and soils corresponds to less carbon released to the atmosphere in response to climate change, and a weaker positive feedback between carbon and climate and a weaker amplification of additional warming," the authors write.

The paper concludes by saying, "There is also a need to better understand the control of respiration itself. The development, testing and adoption of a mechanistic and bio-chemical model of plant respiration are needed. To more reliably project plant respiration and climate-carbon feedbacks in a future climate, this modeling must incorporate response to temperature, including acclimation, at time scales from minutes to years."

On a global scale, plants release about 60 gigatons of carbon dioxide to the atmosphere each year as they carry out their life functions.

Other authors of the Perspectives piece were Carla Gunderson, Wilfred "Mac" Post, David Weston and Stan Wullschleger of the Environmental Sciences Division.
-end-
The research was funded by the Department of Energy's Office of Science/Biological and Environmental Research. UT-Battelle manages Oak Ridge National Laboratory for the Department of Energy.

NOTE TO EDITORS: You may read other press releases from Oak Ridge National Laboratory or learn more about the lab at http://www.ornl.gov/news.

DOE/Oak Ridge National Laboratory

Related Climate Change Articles from Brightsurf:

Are climate scientists being too cautious when linking extreme weather to climate change?
Climate science has focused on avoiding false alarms when linking extreme events to climate change.

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.

Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.

Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.

Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.

Read More: Climate Change News and Climate Change Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.