A global view

But it's when the focus returns to our own planet that things get really interesting. The Earth-observing satellites built by Astrium are helping with the battle against the biggest threat the world has ever faced: climate change. Peter Cheney, thermal engineer and shop steward, explains why weather satellites are essential for monitoring climate change: "To combat global change, you need to have a global view, and you can't have a global view from the ground."

Currently that global view is given to us by ENVISAT, a satellite launched as part of Europe's biggest and most complex Earth observation mission to date. "It's about the size of a bus, a single-decker bus," says Peter. ENVISAT orbits the earth every two hours and returns high-quality data on ten different aspects of environmental change including wave height, wind speed and ozone layer thickness. When the European Space Agency was planning ENVISAT, it chose Astrium UK for the most crucial part: creating all the instruments for measuring the Earth's environment and the technology for sending that data back to Earth. (The work was done at its now-defunct Bristol plant.) Astrium's French and German sites were also heavily involved.

Scientists agree that the Earth's temperature risks hitting a "tipping point" where climate change becomes unstoppable. Where they disagree is how soon we'll reach it and whether or not it's already too late. Accurate measurements of global climate change indicators - sea temperatures, wind speeds, polar ice thickness and so on - are vital for feeding into computer models and helping scientists to evaluate the threat. But the potential for satellites to help us cope with climate change goes beyond even that.