The proof is pretty darn conclusive that climate change leads to more people getting sick and dying. In fact, some scientists say the connection is so clear that they are using climate change data to predict when and where future deadly epidemics will occur.

A small increase in the earth’s temperature (2 degrees Celsius), significantly increases health hazards from insects, natural disasters, and allergens. For instance, disease-carrying mosquitoes are now able to survive in areas that had previously been too cold for them. That means thousands of people in the mountains of Kenya who had no previous exposure are contracting malaria and dengue fever.

Also, global warming is changing weather patterns, producing flooding in some areas and drought in others. Flooding often pollutes the water supply, causing diseases like cholera, while drought causes crop failures and starvation.

Finally, while it might sound minor in comparison to the first two issues, higher temperatures are making allergies and asthma much more severe. Spring now comes earlier---on average 14 days earlier than 20 years ago in the Eastern US---which raises pollen levels. More people are suffering from allergic asthma and their attacks are expected to get worse.

The WHO says climate-sensitive diseases now kill millions of people each year, and those numbers will only increase.