CO2 levels hit 800,000-year record

Source: Scott Waldman, E&E News reporter • Posted: Wednesday, November 1, 2017

The rate of carbon dioxide being released into the atmosphere accelerated at an unprecedented pace last year and has reached levels not seen in 800,000 years.

The amount of CO2 hovering above the planet reached 403.3 parts per million in 2016, up from 400 ppm a year earlier, according to the World Meteorological Organization. The increase was driven by human activity, like burning fossil fuels, and the natural weather pattern El Niño, the group said in a report released yesterday.

“Rapidly increasing atmospheric levels of CO2 and other greenhouse gases (GHGs) have the potential to initiate unpredictable changes in the climate system, because of strong positive feedbacks, leading to severe ecological and economic disruptions,” the report states.

The rate of CO2 increase over the last 70 years is 100 times greater than at the end of the last ice age, researchers found. In the early 1960s, when scientists first began measuring CO2 emissions, they stood at less than 320 ppm.

Before the Industrial Revolution began in about 1750, the amount of atmospheric CO2 was stable at about 280 ppm, as it had been for the last 800,000 years. In particular, the rate has increased dramatically in the last 150 years, according to the report, and is largely driven by human-related carbon emissions from the use of electricity and motorized transport, as well as deforestation.

Current levels of CO2 correspond to the Pliocene period from 3 million to 5 million years ago, when the climate was 3.5 to 5.5 degrees Fahrenheit warmer, the report found. At that time, the ice sheets of Greenland and West Antarctica were melted. Sea levels were 30-60 feet higher than they are now.

The rise in CO2 corresponds with rising temperatures. Globally, 2016 was the warmest year on record, the third consecutive year that record was set, since modern record-keeping began in 1880. This year is on track to be the second warmest on record.

“CO2 remains in the atmosphere for hundreds of years and in the oceans for even longer,” WMO Secretary-General Petteri Taalas said in a statement. “The laws of physics mean that we face a much hotter, more extreme climate in the future. There is currently no magic wand to remove this CO2 from the atmosphere.”