The American people are already feeling the impact of global warming; this message is clear in the draft of a US National Climate Assessment Report that was released in January 2013.
“Corn producers in Iowa, oyster growers in Washington and maple syrup producers in Vermont have observed changes in their local climate that are outside their experience,” states the report.
Since 1895, the average temperature has risen by 0.8 C, and 80 per cent of this increase has occurred since 1980. In the last 50 years much of the country has experienced longer periods of extremely high temperatures, an increase in heavy rains and in some regions severe drought.
A team of 240 scientists wrote the report and it is the third time this kind of assessment has been carried out. A final version will be issued after a revision when scientists and the public have been given the opportunity to submit comments.