CO2 concentrations set to hit symbolic high of 400 ppm


30
Apr 2013

Average carbon dioxide concentration in our atmosphere is likely to pass the symbolically important 400 ppm ceiling for the first time in the next few days.

Hourly readings above 400 ppm were recorded  last week at the Earth Systems Research laboratory in Hawaii. The station is located on Mauna Loa, 3400 m above sea level, and of course far from any major pollution sources. It is considered the “least tainted” measure of atmospheric carbon dioxide concentration, and is used as the yard stick for global concentrations. Monitoring has been ongoing for 50 years, giving a clear picture of increasing carbon dioxide in our lower atmosphere.

Daily readings can be viewed on the laboratory’s website http://www.esrl.noaa.gov/gmd/ccgg/trends/weekly.html During the past week average concentration was 398.68 ppm but the peak is not expected until mid May.

Passing the 400 ppm ceiling means that the internationally “accepted” increase in global average temperature of 2°C will very likely be surpassed resulting in greater environmental impacts. Warnings last year of temperature increases of up to 4 °C by the end of the century seem to be ever more probable.

Governments are currently discussing at the low-key inter-sessional meeting on climate change in Bonn their commitment to greenhouse gas reduction for the next commitment period commencing in 2020. 2015 is the deadline.This meeting is the first in many to decide what level of ambition governments are willing to commit to, and what ways greenhouse gas emissions can be reduced in order to achieve the ambition.

Hitting the 400 ppm will hopefully remind delegates in Bonn that current action simply isn’t enough. An international, united effort is needed to curb the potential impacts of climate change. Many view cutting emissions as a burden to the economy and to society. In fact it is an opportunity for innovation and creative solutions. Countries such as Denmark are an example of this.

 

 

SCRIPPS INSTITUTION OF OCEANOGRAPHY AT UC SAN DIEGO