256 Kyoto Treaty coastal flooding, extreme weather, and food shortages due to crop failures Not all scientists accept the global warming hypothesis, however Alternative explanations include the argument that the increase in temperature has not been clearly established, that it is within the range of normal variation to be expected over time, or that it is due to the period when measurement began having been unusually cold Others argue that although the global temperature does seem to be rising, there is no proof that the rise in temperature was caused by human activity See also environmental problems Further reading: Kyoto Protocol to the United Nations Framework Convention on Climate Change, http://law-ref org/KYOTO/index.html; Maslin, Mark Global Warming: A Very Short Introduction Oxford: Oxford University Press, 2004; Viktor, David G The Collapse of the Kyoto Protocol and the Struggle to Slow Global Warming Princeton, NJ: Princeton University Press, 2004 Sarah Boslaugh A hurricane photographed from space Global warming is predicted to lead to a rise in sea levels and more frequent hurricanes