Observer: The draft version of the US National Climate Assessment, released on Friday, makes remarkable reading not just for Americans but for all humanity. Put together by a special panel of more than 240 scientists, the federally commissioned report reveals that the US is already reeling under the impact of global warming. Heatwaves, droughts, floods, intense downpours, rising sea levels and melting glaciers are now causing widespread havoc and are having an impact on a wide range of fronts including health...