Headline: Symbolic crossing of the 400 ppm threshold for CO2: “Not a call to panic but a call to action”

Reacting to the news of NOAA (National Oceanic and Atmospheric Administration) that the level of carbon dioxide in the Earth’s atmosphere has passed the 400 parts per million mark (relating to the CO₂ particles per million air particles), IASS Scientific Director PD Dr. Mark Lawrence highlights its great symbolic significance, reminding us that we have driven our world into a new epoch – the Anthropocene:

“Here our global environmental influence is reflected by CO₂ levels that have not been experienced for millions of years. This is a clear call for action to reduce our CO₂ emissions – before the day comes when the 500 ppm level is staring us in the face. However, it is NOT a call to panic. We should not apply the 400 ppm threshold as a reason to prematurely reach for “climate engineering” measures. Although these are being discussed more and more broadly, all of the various proposed measures are poorly understood and therefore risky – both for the physical environment, as well as for our societal interactions (for instance – who gets to control the “global thermostat”?). At present, given the very poor information basis, the knee-jerk reaction of reaching for climate engineering could easily be considerably more dangerous than crossing the 400 ppm threshold itself.”

The level was measured at the NOAA’s Mauna Loa Observatory, Hawaii. For further information visit http://researchmatters.noaa.gov/news/Pages/CarbonDioxideatMaunaLoareaches400ppm.aspx