The worldwide average CO2 level surpassed 400 ppm in 2015, which NOAA said was a 43-percent increase over pre-industrial levels. According to NOAA, the average amount of CO2 in the atmosphere between about 10,000 years ago and the start of the industrial revolution was about 280 ppm.
Air samples taken at Mauna Loa are sent to NOAA’s Earth System Research Laboratory in Boulder, where researchers like lead scientist Pieter Tans verify the measurements.
Tans said the 6-ppm increase in CO2 levels in the past two years is unprecedented.
“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,” Tans said. “This is a real shock to the atmosphere.”
Carbon dioxide is one of several greenhouse gases that trap heat in Earth’s atmosphere, thereby warming the planet. This process keeps our planet habitable, but as CO2 levels increase, it’s becoming increasingly warmer.
Tans said human use of fossil fuels is the main driver behind worldwide CO2 increases, which have been observed at other sites in NOAA’s Global Greenhouse Gas Reference Network.
When the Mauna Loa observatory started measuring CO2 increases in 1959, the average annual growth rate was less than 1 percent.