Global warming is caused by increased greenhouse gases from human industrial activity trapping more heat in the atmosphere. This warming is projected to cause sea level rise from melting ice caps that could flood coastal cities and cost billions of dollars in damage. Other impacts include more extreme weather, spreading of diseases, and animals migrating toward the poles. Effects are already seen like decreasing wetlands and forests as well as disappearing ponds. Actions are needed at all levels from individuals to internationally to transition to renewable energy, reduce emissions, and mitigate further impacts.