Carbon dioxide levels hit new record, now more than 50% higher than pre-industrial times

Subject: Environment

Section: Places in news

Context:

Atmospheric concentrations of carbon dioxide have recorded a new high, with the monthly average in May touching 424 parts per million, a new update from National Oceanic and Atmospheric Administration of the United States said.

Details:

The current concentrations are now more than 50 per cent higher than the pre-industrial times.

Greenhouse gas emissions:

Carbon dioxide is the most common among greenhouse gases responsible for causing global warming that is leading to climate change.
Other major greenhouse gases are methane, nitrous oxide, a set of fluorinated gases like HFCs and HCFCs, and ozone.
Carbon dioxide, generated during the process of burning fossil fuels, accounts for over 70 per cent of all human-induced greenhouse gas emissions.

Tracing the CO₂ emissions throughout the geological past:

Scientists have been able to estimate carbon dioxide concentration levels till about 400,000 years in the past, mainly through the study of polar ice cores that have remained unchanged for millions of years.
In this period, CO2 concentrations have remained around 200 ppm during the ice ages, and about 280 ppm during the warmer inter-glacial periods.
But since the middle of last century, CO2 levels have remained at unprecedented levels and have been rising rapidly.
In May of 1990, the year that is generally considered as the start of a phase of climate awareness and response, monthly average concentrations of CO2 was around 357 ppm.
The monthly average crossed the 400 ppm mark for the first time in May 2013.