The International Federation of Red Cross and Red Crescent Societies says extreme weather and natural disasters have killed more than 400,000 people worldwide since 2010. A United Nations report says a quarter of the world's disease burden now stems from environment-related risks with pollution causing some 9 million premature deaths every year. Climate change is worsening water scarcity in some areas caused by lack of enough rainfall. It's also accelerating crop loss due to disruptions in insect migration, leading to more malnutrition, famine and death.