1. Environmental and Societal Impacts Group, National Center for Atmospheric Research, P.O. Box 3000, Boulder Colorado 80307;,
2. Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, Massachusetts 02543;
3. Pacific Northwest National Laboratory/Joint Global Change Research Institute at the University of Maryland, 8400 Baltimore Ave. Suite 201 College Park, Maryland 20740;
4. Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523;
5. Climate and Global Dynamics Division, National Center for Atmospheric Research, P.O. Box 3000, Boulder, Colorado 80307;