A federal agency has awarded two researchers at Scripps Institution of Oceanography, UC San Diego and colleagues $1.2 million to develop methods to quantify regional greenhouse gas emissions from atmospheric measurements, a capability expected to become more important as legislation to reduce global warming becomes more widespread and greenhouse gas emissions trading markets emerge.
Scripps geochemistry professors Ray Weiss and Ralph Keeling will join colleagues at Lawrence Livermore National Laboratory in Livermore, Calif. in a three-year project that will be based on continuous measurements of atmospheric greenhouse gases at two California locations. Computer models at Lawrence Livermore will analyze these measurements to trace emissions of the gases back to their sources.
Funded by the National Institute of Standards and Technology (NIST), the science team will focus initially on industrially produced greenhouse gases not produced biologically that are used as refrigerants, solvents and in manufacturing processes that have limited types of sources and are relatively easy to trace. The method of using atmospheric measurements is often referred to as a "top-down" approach to emissions monitoring, as compared to "bottom-up" techniques that rely on estimates of emissions at their sources. Recent research by atmospheric scientists has shown that many gases are emitted to the atmosphere in concentrations significantly different from those estimated by "bottom-up" methods that are reported to regulatory agencies.
Weiss has likened the current lack of "top-down" verification to going on a diet without weighing oneself.
"The climate doesn't care what emissions we report. The climate only cares about what we actually emit," he said.
Verification of greenhouse gas emissions became a key issue between China and the United States during United Nations-led climate talks in Copenhagen in December.
Weiss said the newly funded research is a pilot program that will yield emissions "maps" focusing on California and western North America that could be expanded to other regions as measuring and modeling capabilities improve.
"Without a credible assessment of sources, you can't have a credible trading scheme," said Keeling. "Carbon markets today depend on a certain amount of hope and faith. Our aim is to make it possible to base these markets on solid numbers."
Carbon dioxide is the most significant greenhouse gas produced by human activities, contributing about twice the warming effect of the other major greenhouse gases combined. But for gases like CO2, methane and nitrous oxide that are heavily affected by natural and human-influenced biogenic processes, it is relatively difficult to disentangle natural from human-made emissions, so these gases will be studied in a later phase of the work, the researchers said.
Another reason to focus initially on industrial greenhouse gases is that these gases, many of which are thousands of times more potent per unit of emissions than CO2, play a disproportionately large role in carbon equivalent trading markets.
Atmospheric measurements are made at Scripps-operated stations located at Trinidad Head on the Northern California coast and on the Scripps campus in La Jolla, Calif. Both stations are part of NASA's Advanced Global Atmospheric Gases Experiment (AGAGE) network, of which Weiss is a principal investigator.
The work will require the capability to detect trace gases and an understanding of localized wind dynamics to create reliable computer representations of emissions activity, the researchers said. Joining Weiss and Keeling in the experiment are Philip Cameron-Smith and Donald Lucas at Livermore. The Livermore team will employ computer models originally developed for emergency situations in which officials attempt to predict the spread of toxic emissions following industrial accidents. The team will run these models in reverse to locate and quantify greenhouse gas emissions.
NIST funded the project through its Measurement Science and Engineering Research Grants Program, which is made possible through the American Recovery and Reinvestment Act. The project includes a research component for making standards for measurements of trace gases.
NIST also awarded $1.5 million to Benson Shing, a structural engineering professor at the Jacobs School of Engineering at UCSD. Shing will seek to develop methods and improve design requirements for the seismic resistance design of shear walls in reinforced masonry buildings in efforts to enhance the cost-effectiveness and performance of these structures.