Subject: NACP Date: Tue, 25 Sep 2001 20:04:30 -0400 From: Gregg Marland To: harriss@ucar.edu CC: nacp@io.harvard.edu As I prepare to head out of town for a while (Sendai) I am aware that I have not yet contributed promised words for the NACP draft. Let me suggest some words and some ideas based on the discussions in Boulder. Again, Bob, adapt this as you see appropriate and pass the remnants on to Steve. 1.) I suggest the text on pages 4-8 of the draft needs some pleasant words about the importance of the human system. I have not yet drafted what exactly might be needed. 2.) The rest of the introduction, through page 10, needs nothing more about the human system 3.) Section 2, "Description of the Major Program elements of the NACP" needs some more words. There is one paragraph in the middle of page 21 that is well positioned and well intentioned. I suggest a bit more and offer some paragraphs below that may fit the bill and could be simply inserted into page 21. 4.) Section 3. "Synergy with other major areas of scientific research" seems to need nothing more on the human system. I will be glad to try to help fit words into the first 4 pages, or to review a next draft, but just could not get it done before Sendai. cheers, Gregg A couple of paragraphs for page 21. Humans now play a major role in the global cycling of carbon and unraveling the natural components of the cycle will require careful characterization of the human components. Understanding the human aspects of the carbon cycle involves both 1.) analysis of the spatial and temporal distribution of emissions and 2.) understanding how efforts to control carbon flows in one area will impact the full system. Emphasis in this program will be on the spatial and temporal distribution of emissions. The detailed analyses envisioned here (both forward and inverse approaches) will require refined inventories of anthropogenic emissions of CO2, CH4, and CO. Emissions from fossil fuels will need to be characterized by fuel in order to allow estimation of carbon isotope signatures. We envision that the requisite analyses would be carried out using a multi-phase strategy. The first phase would involve emissions inventories on the approximate scale of months and U.S. counties. The spatial and temporal distribution of sources is highly variable and further phases would be required to better describe the variability with time of day, day of the week, and climate, for example. We would be interested to know the extent to which these variations can be described with simple algorithms. What are the linkages between human emissions and the climate system? Intensive campaigns will require additional time and site-specific evaluation of human sources of greenhouse gases. Emissions from large point sources, for example, can be highly variable on small temporal and spatial scales as power plants are taken down for maintenance and adjusted to meet load demand. In the context of specific focused campaigns to understand the functioning of the North American carbon cycle, it is possible to think in terms of human emissions, especially those from large point sources, as a variable that might be manipulated. What is needed is a set of spatially and temporally resolved data bases for human sources of CO2, CH4 and CO. To use these data bases in resolving other questions about the North American carbon cycle will require emissions time series at the finest possible spatial and temporal scales. We also need a better description of the uncertainties in these values. Detailed description of the anthropogenic fluxes will allow rigorous tests of emissions inventories as well as the fidelity of transport sub-models. The goal is to distinguish the fossil-fuel and other human signals for the major carbon gases from other sources of variance, allowing quantification of ecosystem fluxes and other non-human influences. ---------------------------------------------------------------------- Gregg Marland 865-241-4850 phone Environmental Sciences Division 865-574-2232 fax Oak Ridge National Laboratory gum@ornl.gov Oak Ridge, TN 37831-6335 USA