This edition of environment mattersarrives just as the international community embarks on atwo-year process to secure a new global framework to limitthe amounts of greenhouse gases (GHGs) entering theatmosphere and devise ways to help developing countriesadapt to and prepare themselves for the effects of climatechange. At the World Bank, the author believe that climatechange, and developing countries' adaptation to it, isa critical challenge of our time that must be integratedinto core development strategies. Changes in temperaturesand weather patterns will affect the frequency and severityof rainfall, droughts, floods, and access to water, floodprotection, health, and the use of land. These impacts willnot be evenly distributed. The poorest countries and people,those least responsible for climate change and least able tocope with it, will suffer earliest and most due to theirgeographical location, low incomes, and low institutionalcapacity, as well as their greater reliance onclimate-sensitive sectors like agriculture. This is whybuilding up resilience to increasing climate variability isthe most significant climate challenge facing manydeveloping countries. But we believe that adaptation, whilenecessary in and of itself, can also serve to meet thedevelopment objectives of countries. Many appropriateadaptive measures are consistent with good developmentpractice. They can improve the local environment, increaseresilience to current and future climate variability and tonatural disasters, and ease the dissemination of innovativetechnologies. They can also reduce resource scarcity withinspecific social groups or regions, thereby addressing someof the principal causes of social unrest and violent strife.In other words, climate action is development action.