Palustrine wetlands(PWs) include all bogs, fens, swamps and marshes that are non-saline and which are not lakes or rivers. They therefore form a highly important group of wetlands which hold large carbon stocks. If these wetlands are not protected properly they could become a net carbon source in the future. Compilation of spatially explicit wetland databases, national inventory data and in situ measurement of soil organic carbon (SOC) could be useful to better quantify SOC and formulate long-term strategies for mitigating global climate change.

Your Editorial 'A fresh approach to water' (Nature 452, 253; 2008) points out that the world's looming water crisis is driven by climate change, population growth and economic development. In China, changing food-consumption patterns are the main cause of the worsening water scarcity. If other developing countries follow China's trend towards protein-rich Western diets, the global water shortage will become still more severe. (Correspondence)