Global warming is caused by human activity according to the scientific consensus. 97% of climate studies from 1991-2011 that expressed a position on the cause of global warming supported the view that it is human-caused. National science academies have called on world leaders to cut global emissions. Multiple lines of evidence show the climate is warming, with most additional energy since 1970 going into ocean warming. Future climate change will differ by region and include rising sea levels and changes in precipitation patterns as well as likely expansion of deserts. Effects on humans include threats to food security and loss of habitat.