METHANE, a long-lived gas (8–10 years residence time), is important in the chemistry of the atmosphere and the Earth's radiation balance1–3. The tropospheric abundance of CH4 has been increasing by ˜1.1% yr–1 over the past decade4,5. The cause of this increase may be due to either increases in global sources or decreases in global sinks1,6,7. Although considerable research has focused on measuring CH4 emissions from major biological sources7,8, much less is known about the magnitude of, and factors controlling, biological sinks of CH4. The largest biological sinks for methane are microorganisms in aerobic soils7. Here we report a study of CH4 uptake by aerobic temperate-forest soils. We measured CH4consumption rates (up to 3.17 mg CH4–C m–1 day–1) that were higher than reported previously. Globally, soils of temperate and boreal forests may consume up to 9.3 Tg CH4–C yr–1. We also found that the CH4 uptake rates of these soils were decreased significantly by elevated soil moisture (14%) and nitrogen additions (33%), implying that nitrogen fertilization may reduce this CH4 sink.