Atmospheric concentrations of the most prevalent climate-altering greenhouse gas set an ominous double record in 2016, according to the U.S. National Oceanic and Atmospheric Administration (NOAA), reporting benchmark measurements from its Mauna Loa Observatory in Hawaii.
Carbon dioxide levels at Mauna Loa rose by 3 parts per million in 2016 and reached 405.1 ppm, matching “the record jump observed in 2015,” the agency reports in a release. “The two-year, 6-ppm surge in the greenhouse gas between 2015 and 2017 is unprecedented in the observatory’s 59-year record.” 2016 also marked a record fifth consecutive year in which the observatory recorded a 2 ppm or greater increase in atmospheric carbon dioxide, NOAA notes.
“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,” said Pieter Tans, lead scientist of NOAA’s Global Greenhouse Gas Reference Network. “This is a real shock to the atmosphere.”
Global average CO2 levels passed 400 ppm—a 43% increase over pre-industrial levels—two years ago. They previously hovered around 280 ppm for about 10,000 years until humanity began burning coal in volume at the start of the Industrial Revolution, around 1760. By last month, the level at Mauna Loa had climbed above 406.4 ppm.
As global temperatures spike, U.S. public concern about climate change has also hit an all-time high, the Washington Post reports. A new Gallup survey found 68% who understand that climate change is caused by human activity, 62% who believe its effects are already apparent, and 45% who said they worry about climate change “a great deal”.
Those results “are up from a previous high in 2007, when a similar poll found that 41% of respondents worried greatly about climate change,” the Post notes. “Between then and now, American concern about global warming actually declined for four years and has only been on the rise again since 2011. Similarly, the percentage of Americans who believe climate change is already happening previously peaked at 61% in 2008 and then declined until 2011.”
The paper suggests Americans’ attention to climate change might rise and fall with their economic prospects. One study in 2011 “found that an increase in a state’s unemployment rate is associated with both a decreased likelihood that its residents believe climate change is occurring and reduced support for climate action.”