Space junk 'will stay up longer'

[Rick]

US scientists say increased levels of carbon dioxide (CO2) are changing the outer atmosphere, making it easier for orbiting objects to stay aloft.

Dr Stan Solomon and colleagues say the region known at the thermosphere, which extends above 85km, is slowly cooling and contracting.

See http://news.bbc.co.uk/2/hi/science/nature/6184775.stm