Atmospheric CO2 concentration now exceeds 390 ppm (180-300 for past 800,000 years)

Informed by the latest climate science, Australia-based 300.org argues that we must return atmospheric CO2 to 300 ppm, the upper limit of range for the Earth over the last 800,000 years before the industrial revolution (see: 300.org - return atmosphere CO2 to 300 ppm ).

Many climate activists support the 300 ppm target and Australian climate action groups overwhelmingly support the 300 ppm target (see: Climate activists say the safe atmospheric CO2 concentration target is 300 ppm) , as do many top climate scientists (see: climate scientists and biological scientists supporting the need for an atmospheric CO2 concentration in the range 300-350 ppm ).

300.org supports the 350.org 24 Octpber International day of Action and will be participating, no doubt with banners saying "<350" and "300" (see: 300.org supports 350.org global day of action - 24 October 2009 ).