Nearly one quarter of the global disease burden can be attributed to the environment. Indoor air pollution, vector-borne disease, limited access to clean water and sanitation and poor land management are among the biggest killers, costing more than 100 million disability-adjusted life years every year. Changing climates are set to worsen the problem — by 2030, an estimated 310 million people are expected to have suffered ill health from climate change. Nine out of ten of these people will be in developing countries. Improving environmental health — raising its profile at national, state and local levels, and integrating environmental health issues into development plans and activities — is critical if we are to reduce poverty and meet the Millennium Development Goals.