Recently, the Carbon dioxide levels in the atmosphere scaled another psychologically important and immensely worrying peak, going past 410 parts per million (ppm).
At the end of September 2016, scientists announced that CO2 levels were likely to stay above 400 ppm “for the indefinite future”.
What did the statistics say?
Levels measured at Mauna Loa have risen every year since 1959, going from 315.97 ppm that year to 404.21 in 2016.
The US National Oceanic and Atmospheric Administration (NOAA) noted that this year that CO2 had risen by 2 ppm or greater for a record five years in a row.
The rate of CO2 growth over the last decade is 100 to 200 times faster than what the Earth experienced during the transition from the last Ice Age.
Atmospheric carbon dioxide concentrations are now at the highest levels they have been in at least 3 million years.
More importantly, over the past couple of years, they have increased faster than probably ever before.
Why is an increased level of CO2 bad for the Earth?
CO2 is one of several gases that trap heat in the atmosphere, creating the “greenhouse effect” that keeps the Earth from getting too cold for life.
But if the CO2 increases, extra heat is trapped in the atmosphere, and global average temperatures begin to rise.
The more the CO2, the greater the atmosphere’s capacity to trap heat.
For the last several years, global emissions of fossil fuel CO2 appear to have levelled off. However, this happened while it is at a record high. As a direct result, the rate of atmospheric CO2 increase also remains at a record high.
The main reason is that the extra CO2 cannot be removed from the ocean-atmosphere system for thousands of years.
Also increasing CO2 concentration is vegetation. There is a roughly 7 ppm swing between the peak and trough values in a year, mainly because in winter in the northern hemisphere, the dormant vegetation doesn’t remove CO2 from the air.
Similarly, a drought caused by a strong El Niño event could trigger a spike in CO2 levels.
A minor comfort is that concentration levels could fall below the 410 ppm mark as daily measurements fluctuate — but if there is no drastic action, there could be no reversal.
The concentration is not expected to fall below 400 ppm any time soon in any case.
Are there any efforts taken to control this?
The Paris Agreement, considered an achievement of global action in which all nations came together and vowed to keep global temperature rise to below 2 degrees Celsius above pre-industrial levels, also resolved to pursue efforts to limit temperature increase further to 1.5 degrees Celsius.
Some scientists say that to do that, the upper limit for CO2 concentrations would have to be 450 ppm.
