Bookmark and ShareAndy Wimbush is nef‘s Communications Assistant and blogmaster.

The first number is 350. If you haven’t memorised the number 350 yet, then you probably should. Write it on your hand. Scribble it on every surface you can find. Put it in your phone. Paint pictures of it. Hell, tattoo it to yourself if need be. Three hundred and fifty is, according to NASA climate scientist James Hansen, the number which represents the safe amount of carbon dioxide in our atmosphere: 350 parts per million (ppm). If we exceed 350, we’re heading towards dangerous climate change. The fact that we’re currently at over 380 ppm is all the more reason to start doing something.

The second number is 24.10.09, which stands for 24th October 2009.  That’s when the ‘doing something’ part really kicks off. Our friends at – the campaign headed up by Dr Hansen and Bill McKibben – have chosen 24th October as a day of global action on climate change. nef has some exciting plans for this day already (more of which to be revealed in due course), but for now, check out this little trailer and start dreaming up some actions of your own: