The 2008 ozone hole - a thinning in the ozone layer over Antarctica - is larger both in size and ozone loss than 2007 but is not as large as 2006. Ozone is a protective atmospheric layer found in about 25 kilometres altitude that acts as a sunlight filter shielding life on Earth from harmful ultraviolet rays, which can increase the risk of skin cancer and cataracts and harm marine life.

After reaching the second-lowest extent ever recorded last month, sea ice in the Arctic has begun to refreeze in the face of autumn temperatures, closing both the Northern Sea Route and the direct route through the Northwest Passage.

Residents along the Gulf Coast are bracing for Hurricane Ike as it travels over the Gulf of Mexico after ripping through Cuba and Haiti. ESA's Envisat satellite is tracking the storm, which is forecast to make landfall on the Texas coast by 13 September.
Thanks to Envisat's unique capability to acquire optical and radar imagery over the same area of the Earth simultaneously, the top and bottom of a hurricane can be viewed at the same time.