Listed below are areas where the Carbon Cycle Science Initiative had made noteworthy progress and breakthroughs as of Fiscal Year 2000:

Extension of climate and trace-gas record back to 400,000 years before present through studies of Antarctic ice cores

Comparison of U.S. and European network of flux tower data revealed that uptake of atmospheric CO₂ by the terrestrial biosphere appears to correlate with climatic zone

Application of inverse methods to the carbon cycle-- atmospheric data and models reveal large sink over North America which, although not yet of the same magnitude as that measured with current in situ techniques, provides comparison and stimulates progress toward sink quantification and location

International intercomparison of atmospheric transport models revealed major discrepancies in simulating transport and reveal key observations needed to improve models

Manipulation experiments show link between stimulation of growth by CO₂ fertilization and water availability

Analyzed patterns of land use in the United States, which revealed that forest regrowth and fire suppression play a major role in storage of carbon on land.

Published a report estimating the potential of U.S. cropland to sequester carbon.  A similar effort is underway for rangelands and pastures.

Successfully implemented projects in Iowa and Montana to encourage changes in land management and measure associated soil carbon.

Measured air-sea CO₂ flux directly for the first time using meteorological techniques on-board ship-- this result paves the way for progress in understanding the processes controlling uptake of carbon by the ocean. (Fig 5 and 6)

Estimated the magnitude and distribution of carbon released to the atmosphere by human activity that was eventually stored in the Indian Ocean as part of the global ocean carbon synthesis effort.  The synthesis will provide an inventory of carbon storage in the world's oceans based on observations--previous estimates of the ocean sink had relied solely on model simulations.

Hurricanes appear to increase transport of CO₂ from the ocean to the atmosphere, suggesting a potential feedback under climate change.

Export of carbon to the deep sea appears to depend strongly on the type of organism present in surface waters, rather than plant biomass as a whole.

Major Fiscal-Year 2000 Accomplishments