A new UN report notes record increases in the concentration of carbon dioxide in the atmosphere, reaching levels not seen on earth in at least 800,000 years. Ahead of a new round of climate negotiations in Germany, the report has led experts to call for more drastic action to reduce emissions.
According to The Greenhouse Gas Bulletin, the annual report of the UN’s World Meteorological Organization (WMO):
“Globally averaged concentrations of CO2 reached 403.3 parts per million (ppm) in 2016, up from 400.00 ppm in 2015 because of a combination of human activities and a strong event.”
The report says CO2 is rising 100 times faster than at the end of the last ice age, citing industrialization, intensive agriculture, deforestation, and population growth as causes. The last time the planet underwent similar rates of CO2 concentration was during the Pliocene era, between three and five million years ago. Sea levels at the time were as much as 20 meters higher than today.
Emissions from human activities have slowed in recent years, and possibly have even plateaued. However, a strong El Niño exacerbated droughts and limited the carbon dioxide absorbed by vegetation. As a result, the CO2 in the atmosphere continued to increase. Scientists expect El Niño events to become more frequent as global temperatures continue to rise.
The 3.3 ppm increase far outstrips the 2.3 ppm rise of the previous 12-month period, as well as the 2.08 ppm average increase of the past decade. During the last strong El Niño event in 1998, CO2 rose by 2.7 ppm.
According to the WMO, direct measurements from the past 800,000 years have relied on “modern instruments” as well as Antarctic ice cores.
The new study used monitoring ships, aircraft, and land-based stations to monitor emissions trends since 1750, considered to be the start of the industrial age.
According to a statement by WMO chief Petteri Taalas:
“Without rapid cuts in CO2 and other greenhouse gas emissions, we will be heading for dangerous temperature increases by the end of this century, well above the target set by the Paris climate change agreement.”
National efforts to reduce emissions have fallen short in many cases, and President Trump has indicated that the US, the world’s second largest emitter of CO2, will back out of the deal altogether.
“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.”