Sky high: Carbon dioxide in air surges past a `terrifying' level

The amount of heat-trapping carbon dioxide in the atmosphere has shot past a key milestone — more than 50% higher than pre-industrial times — and is at levels not seen since millions of years ago when Earth was a hothouse ocean-inundated planet, federal scientists announced Friday.

The National Oceanic and Atmospheric Administration said its longtime monitoring station at Mauna Loa, Hawaii, averaged 421 parts per million of carbon dioxide for the month of May, which is when the crucial greenhouse gas hits its yearly high. Before the industrial revolution in the late 19th century carbon dioxide levels were at 280 parts per million, scientists said, so humans have significantly changed the atmosphere. Some activists and scientists want a level of 350 parts per million. Industrial carbon dioxide emissions come from the burning of coal, oil and gas.

Levels of the gas continue to rise, when they need to be falling, scientists say. This year's carbon dioxide level is nearly 1.9 ppm more than a year ago, a slightly bigger jump than from May 2020 to May 2021.

“The world is trying to reduce emissions, and you just don't see it. In other words, if you're measuring the atmosphere, you're not seeing anything happening right now in terms of change,” said NOAA climate scientist Pieter Tans, who tracks global greenhouse gas emissions for the agency.

Outside scientists said the numbers show a severe climate change problem.

“Watching these incremental but persistent increases in CO2 year-toyear is much like watching a train barrel down the track towards you in slow motion. It's terrifying,” said University of Wisconsin-Madison climate scientist Andrea Dutton.