June 6, 2011 - The tropics and much of the Northern Hemisphere
are likely to experience an irreversible rise in summer
temperatures within the next 20 to 60 years if atmospheric
greenhouse gas concentrations continue to increase, according to
a new climate study by Stanford University scientists. The
results will be published later this month in the journal
Climatic Change. In the study, the Stanford team concluded that
many tropical regions in Africa, Asia and South America could
see "the permanent emergence of unprecedented summer heat" in
the next two decades. Middle latitudes of Europe, China and
North America – including the United States – are likely to
undergo extreme summer temperature shifts within 60 years, the
researchers found. "According to our projections, large areas of
the globe are likely to warm up so quickly that, by the middle
of this century, even the coolest summers will be hotter than
the hottest summers of the past 50 years," said the study's lead
author, Noah Diffenbaugh, an assistant