2+2=5? Copenhagen targets add up to 750 ppm

Here is the critical point to remember if a compromise agreement is somehow salvaged by the end of this week: the emission reduction commitments currently on the table add up to global atmospheric carbon concentrations of approximately 750 ppm . That means 4C average global temperature rise by the end of the century, agricultural wipeout, mass extinctions and almost certain runaway heating of the planet. If Copenhagen produces another political statement that claims to be aimed at limiting warming to 2C and carbon concentrations of 450 ppm, citizens around the world should be in no doubt that they are being lied to by their leaders.