Soils store about four times as much carbon as plant biomass, and soil microbial respiration
releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide. Short-
term experiments have shown that soil microbial respiration increases exponentially with
temperature. This information has been incorporated into soil carbon and Earth-system
models, which suggest that warming-induced increases in carbon dioxide release from soils
represent an important positive feedback loop that could influence twenty-first-century …

Soils store about four times as much carbon as plant biomass1, and soil microbial
respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon
dioxide2. Short-term experiments have shown that soil microbial respiration increases
exponentially with temperature3. This information has been incorporated into soil carbon
and Earth-system models, which suggest that warminginduced increases in carbon dioxide
release from soils represent an important positive feedback loop that could influence twenty …