Climate change refers to the rise in average surface temperatures on Earth caused primarily by human use of fossil fuels which releases greenhouse gases. These gases trap heat and can cause effects like rising sea levels, more extreme weather, and droughts. Public health is affected by disruptions from climate change like increased respiratory and cardiovascular disease. While there are barriers to addressing climate change like economic and technological limitations, widespread scientific consensus exists that the climate is changing and will negatively impact public health. Organizations are working at local, national and global levels to enact policies and solutions to limit global warming pollution and transition to cleaner energy sources.