We often hear that planting trees can help cool the environment. This may work not only at a household level, but also on the planetary scale-large scale afforestation has been advanced by the United Nations as a means of mitigating global climate change. At the garden level, trees provide shade and relief from the summer heat. On the planetary scale, how do trees help cool the earth? (Guest Editorial)

Climate projections for the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) are made using the newly developed representative concentration pathways (RCPs) under the Coupled Model Inter-comparison Project 5 (CMIP5). This article provides multi-model and multi-scenario temperature and precipitation projections for India for the period 1860–2099 based on the new climate data. We find that CMIP5 ensemble mean climate is closer to observed climate than any individual model.

The accelerated rate of increase in atmospheric CO2 concentration in recent years has revived the idea of stabilizing the global climate through geoengineering schemes. Majority of the proposed geoengineering schemes will attempt to reduce the amount of solar radiation absorbed by our planet.