Do not hide from rain under a firetree . Satellite sniffs out chemical traces of atmospheric pollution . Silt formation better understood . Alaska's speedy Columbia Glacier on likely disintegration course . Less pollution with new system .
Scientists fight to bring the American chestnut tree back to life .
Mouse allergy contributes to inner-city asthma crisis . New filter material can reduce the number of cigarette deaths . First measurement of the long searched for nitric acid crystals in polar stratospheric clouds . Understanding our smog . Washed off the map .