Summary . In the U. S. and across wide regions of the globe, 2011 and 2012 have recorded heat waves and droughts at or near record leve...

Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the ...
Summary . In the U. S. and across wide regions of the globe, 2011 and 2012 have recorded heat waves and droughts at or near record leve...