May 9th then goes down in history as the first time mankind has experienced 400ppm in our atmosphere and that I am afraid is something we collectively should be ashamed about. What we need now is concerted global action to ensure we are not in coming years reporting 420 ppm or worse. I think the time has come for governments across the globe and in particular the big emitters to take positive action to reduce their emissions significantly in the coming years through the rapid deployment of low carbon technology. The time for stalling is over.