Carbon dioxide — the gas scientists say is most responsible for global warming — peaked again at record levels last month, federal scientists announced Thursday.
Levels at NOAA’s Mauna Loa Observatory averaged more than 410 parts per million in April and May, surging past yet another climate milestone.
The Scripps Institution for Oceanography, where scientists first started tracking the gas, found a similar increase.
The concentration of carbon dioxide in the atmosphere increases every year, and the rate of increase is accelerating.
“The emissions that we are causing today will still be in the atmosphere-ocean system thousands of years from now,” said Pieter Tans, a NOAA scientist. "Carbon dioxide levels are continuing to grow at an all-time record rate because emissions from coal, oil and natural gas are also at record high levels.”
“We are as a global society making an extremely long climate-change commitment,” Tans added.
The increase in gases such as carbon dioxide, methane and nitrous oxide is fueling climate change and making "the planet more dangerous and inhospitable for future generations," the World Meteorological Organization has said.
When oil, gas and coal are burned for energy, greenhouse gases such as carbon dioxide and methane are released. These gases have caused the Earth's temperature to rise over the past century to levels that cannot be explained by natural variations.
Carbon dioxide is called a greenhouse gas for its ability to trap solar radiation and keep it confined to the atmosphere.
It is invisible, odorless and colorless yet is responsible for 63% of the warming attributable to all greenhouse gases, according to NOAA's Earth System Research Laboratory in Boulder, Colo.
Levels of carbon dioxide go up and down each year, reaching their highest levels in May and then going back down in the fall as plants absorb the gas.