Forests, soils and oceans are the unsung heroes of our climate, storing the greenhouse gases that cause global heating. But they could perform even better with a little help. Smoking industrial chimneys, exhaust fumes, fires in the Amazon — yearly carbon emissions recently swelled to 12,000,000,000 tons (12 gigatons).And as carbon increases, so do temperatures. Around half of emissions released remain in the atmosphere. Nature absorbs the rest, holding it in carbon sinks, such as soil, oceans and vegetation.