Geophysical Research Letters
Doughty, C. E., L. L. Taylor, C. A. J. Girardin, Y. Malhi, and D. J. Beerling (2014) Cenozoic global change possibly stabilized by montane forest root growth and soil organic layer depth, Geophys. Res. Lett., 41, doi:10.1002/ 2013GL058737.View Journal Article / Working Paper
In a warmer world, tree roots are more likely to grow into the mineral layer of the soil, breaking down rock which will eventually combine with carbon dioxide. This weathering draws carbon dioxide out of the atmosphere and cools the planet. This theory suggests that mountainous ecosystems have acted like the Earth's thermostat, addressing the risk of 'catastrophic' overheating or cooling over millions of years. However these processes act too slowly to have any influence on contemporary global warming.