Office of Biological and Environmental Research Weekly Report

May 18, 2009

New Insights for Climate Change Mitigation: Understanding Human Influences through Land Use and Fossil Fuel Emissions. Science magazine will publish in the May 29, 2009, issue the paper, The Two-Thousand-Billion Ton Carbon Gorilla —Implications of Limiting CO₂ Concentrations on Land Use and Energy by M.Wise, K. Calvin, A. Thomson, L. Clarke, B. Bond-Lamberty, R. Sands, S. Smith, A. Janetos, and

J. Edmonds.  This paper summarizes findings, funded in part by DOE’s Office of Science, that limiting atmospheric CO₂ concentrations to low levels require strategies to manage anthropogenic carbon emissions from terrestrial systems as well as fossil fuel and industrial sources.  The authors explore the implications of fully integrating terrestrial systems and the energy system into a comprehensive mitigation regime that limits atmospheric CO₂ concentrations.  They find that this comprehensive approach lowers the cost of meeting environmental goals but also carries with it profound and largely unappreciated implications for agriculture: unmanaged ecosystems and forests expand, and food crop and livestock prices rise. The authors also find that future improvement in food crop productivity directly affects land-use change emissions, making the technology for growing crops potentially important for limiting atmospheric CO₂ concentrations. The paper derives from a full report by Pacific Northwest National Laboratory, February 2009, entitled, The Implications of Limiting CO₂ Concentrations for Agriculture, Land Use, Land-use Change Emissions and Bioenergy (PNNL 17943).

Media Interest: Yes

Contact: Bob Vallario, SC 23.1 , (301) 903-5758

ARM Mobile Facility Experiment in Azores Begins. A 20-month field campaign began May 1 on Graciosa Island in the Azores to study the seasonal life cycle of marine clouds and how they modulate the global climate system. Sponsored by the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Climate Research Facility, researchers are using the ARM Mobile Facility (AMF) to obtain data for the study entitled “Clouds, Aerosol, and Precipitation in the Marine Boundary Layer.” Marine boundary-layer clouds are found over open oceans and in coastal environments around the world and play a major role in the global climate system. For accurate predictions of future climate, scientists need a better understanding of the dynamic elements that control the life cycle of these cloud types. Detailed observations are critical to improved representations of these clouds in the climate models, but currently these data are lacking. Graciosa is one of the few locations where these clouds may be conveniently observed. A new long-term record of clouds and the processes controlling them will, in the short term, allow scientists to test the skill of existing climate models. Ultimately, the information will lead to model improvement that will increase confidence in climate change predictions.

Media Interest: No

Contact: Wanda Ferrell, SC-23.1, (301) 903- 0043

Recent Data Shows Regional Shifts in Annual Fossil-Fuel CO₂ Emission Estimates. Each year the Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory quantifies the release of carbon from fossil-fuel use and cement production at global, regional, and national spatial scales. The emission time series estimates are based largely on annual energy statistics published at the national level by the United Nations. The latest updates estimate the global release to be 8.23 billion tons of carbon for 2006, an all-time high. Since 1751, CDIAC estimates 329 billion tons of carbon have been emitted to the atmosphere from fossil-fuel burning and cement production, with half the release occurring since the 1970s. According to the latest updates, two countries - the People’s Republic of China and United States - now have annual emissions exceeding 1.5 billion tons of carbon. The U.S. has long been the world’s largest consumer of fossil-fuels and accounted for ~40% of the world’s fossil-fuel carbon emissions in 1950. According to the latest data, China surpassed the U.S. as the world’s largest fossil-fuel emitting nation in 2006 thanks to remarkable recent growth (e.g., a 79% increase in PRC fossil-fuel carbon releases from 2000 to 2006). According to the latest 2006 numbers, U.S. and Chinese emissions are three-to-four times higher than the next largest emitting nations - Russia (427 million tons carbon), India (412), and Japan (353). Regionally, Europe and North America show modest growth in fossil-fuel carbon emissions while emissions from Africa, Asia, and South America continue to grow. For more information and detail, please visit the CDIAC web site at http://cdiac.ornl.gov/trends/emis/overview.html

Media Interest: No

Contact: Wanda Ferrell, SC-23.1, (301) 903- 0043

Sometimes Simpler is Enough – Representing Cloud-Radiation Effects in Climate Models. A challenge of climate modeling is to accurately and sufficiently represent complex climate processes. Although it is well known that clouds scatter and emit radiation in all three dimensions, state-of-the-art global climate models (GCMs) represent atmospheric radiation as simple one-dimensional streams. DOE scientists have now found that statistics for cloud radiative impacts are almost the same for low-level clouds whether cloud-radiative interactions are represented by one-dimensional or three-dimensional approaches. This result resolves a longstanding question, demonstrating that the simplified approach taken by GCMs is adequate to obtain realistic low-level cloud properties and that a more complicated treatment of radiation that allows streams in multiple directions may not be required. This is an important and useful result as climate models continue to increase in complexity and computational intensity.

Reference:

Mechem, D. B., Y. L. Kogan, M. Ovtchinnikov, A. B. Davis, K. F. Evans, and R. G. Ellingson, 2008: Multidimensional longwave forcing of boundary layer cloud systems. J. Atmos. Sci., 65, 3963-3977.

Media Interest: No

Contact: Kiran Alapaty, SC-23.1, (301) 903-3175