- The World Meteorological Organisation (WMO) in its latest Greenhouse Gas Bulletin reported that the amounts of greenhouse gases in the atmosphere have hit yet another record high.
- About WMO: The WMO is the weather agency of the United Nations, and publishes its Greenhouse Gas Bulletin each year.
- This year’s report covers data for 2017.
- Findings of the report:
- There is no sign of a reversal in the trend of rising levels of greenhouse gases in the atmosphere, which is driving long-term climate change, sea level rise, ocean acidification and more extreme weather.
- Without rapid cuts in carbon dioxide and other greenhouse gases, climate change will have increasingly destructive and irreversible impacts on life on Earth.
- The last time the Earth experienced a comparable concentration of carbon dioxide was 3-5 million years ago, when the temperature was 2-3°C warmer and sea level was 10-20 metres higher than now.
- Carbon dioxide: Concentrations of the gas reached 405.5 parts per million in 2017, 146% of the pre-industrial era (before 1750).
- The increase in carbon dioxide from 2016 to 2017 was about the same as the average growth rate over the last decade.
- It was smaller than the record leap observed from 2015 to 2016 (from 401.1 ppm to 403.3 ppm) under the influence of a strong El Niño
- There was no El Niño in 2017.
- Methane: Atmospheric methane reached a new high of about 1859 parts per billion in 2017 and is now 257% of the pre-industrial level.
- Its rate of increase was about equal that observed over the past decade.
- Nitrous Oxide: Its atmospheric concentration in 2017 was 329.9 parts per billion. This is 122% of pre-industrial levels.
- CFC-11: CFC-11 is a potent greenhouse gas and a stratospheric ozone depleting substance regulated under the Montreal Protocol.
- Since 2012, its rate of decline has slowed to roughly two-thirds of its rate of decline during the preceding decade.
- The most likely cause of this slowing is increased emissions associated with production of CFC-11 in eastern Asia according to the bulletin says.