Temperature is a major determining factor of global climate patterns. It affects the life cycles of plants and animals, influences weather and tides, and controls the freeze and thaw of the polar ice caps. A small change in average temperature can have powerful effects on the environment worldwide.
Just a few degrees of overall temperature change can cause plants to wilt or have lower yields and allow invasive species to take hold. Animals like the polar bear can also lose their habitats to ice melt. Mosquitoes can flourish and spread disease. Warming ocean temperatures cause more severe weather patterns and affect the biodiversity of the oceans.