ABSTRACT
Science has earned a kind of authority and legitimacy from centuries of successes and improvements. The demarcation of science from non-science is especially important because some non-scientific projects are designed to look enough like science to deceive people into thinking that these projects too can lay claim to the authority and legitimacy of science. Understanding how scientists acquire new knowledge, the basis for science's authority as a source of knowledge, and the limits of that authority gives us greater reason to trust scientific knowledge. Reputable scientists and scientific societies, including the national science academies of the world and the Intergovernmental Panel on Climate Change, agree that human-caused, or anthropogenic, climate change is occurring. The chapter describes some of the clear and abundant scientific evidence for anthropogenic climate change. The rise in global temperature and resulting climate changes threaten to push some animal and plant species to extinction, collapse ecosystems, and make extreme weather more frequent.
