Nature: Geophys. Res. Lett. 36, L02703 (2009) By losing less water, plants could worsen warming in a high-CO2 world, finds a new study. Stomata — the tiny pores on leaf surfaces that permit the exchange of water and gases with the atmosphere — close under elevated CO2 concentrations, returning less water to the atmosphere through the process known as transpiration. Marie Doutriaux-Boucher of the Met Office Hadley Centre, UK, and colleagues used a coupled carbon–climate cycle model …