Global warming refers to the increase in average surface temperatures of the Earth since the late 19th century, according to scientific consensus. The document then lists specific human behaviors and activities that contribute to greenhouse gas emissions and global warming, such as using excess paper and electricity, driving inefficient vehicles, eating meat, and deforestation. It encourages individuals to make small changes like using less hot water, unplugging appliances, and encouraging organizations to reduce emissions in order to help address the problem of global warming from a grassroots level.