It is very likely that rising levels of greenhouse gases in the atmosphere resulting from human activity are increasing global temperatures and changing Earth's climate. Lawrence Livermore National Lab’s Karis MacFarlane explains about the carbon cycle, ways that forests and soils store carbon, and how carbon storage and loss from forests and soils might change with changes in climate and human activity. Series: "Lawrence Livermore National Lab Science on Saturday" [Science] [Show ID: 20232]