Be set for more extreme weather

A new statistical analysis by NASA scientists has found that Earth's land areas have become much more likely to experience an extreme summer heat wave than they were in the middle of the 20th century. The research was published today in the journal Proceedings of the National Academy of Sciences.

The statistics show that the recent bouts of extremely warm summers very likely are the consequence of global warming, according to lead author James Hansen of NASA's Goddard Institute for Space Studies (GISS) in New York.

Hansen and colleagues analyzed mean summer temperatures since 1951 and showed that the odds have increased in recent decades for what they define as "hot," "very hot" and "extremely hot" summers.

In 1988, Hansen first asserted that global warming would reach a point in the coming decades when the connection to extreme events would become more apparent.  In the new study, the GISS team did not focus on the causes of temperature change. Instead the researchers analyzed surface temperature data to establish the growing frequency of extreme heat events in the past 30 years, a period in which the temperature data show an overall warming trend.

Such anomalies were infrequent in the climate prior to the warming of the past 30 years, so statistics let us say with a high degree of confidence that we would not have had such an extreme anomaly this summer in the absence of global warming, says Hansen.

Other regions around the world also have felt the heat of global warming, according to the study. Global maps of temperature anomalies show that heat waves in Texas, Oklahoma and Mexico in 2011 and in the Middle East, Western Asia and Eastern Europe in 2010 fall into the new "extremely hot" category. Studies have already shown that increased temperatures can affect crop yields ranging from rice, wheat, corn, maize, etc. Price rise. Food scarcity. This in turn can affect global politics in a big way. But sadly this is one Bengal tiger in the room that does not scare any of us! The word of science is simply not enough to scare most of us. That is where, as environmentalist David Orr says, scientists need to speak out the truth, however depressing it be. We need more Hansens to shake us out of our lethargy.