April sets record for highest CO2 levels in human history

Levels of carbon dioxide in the atmosphere reached the highest levels on record for any calendar month during April, averaging 420 parts per million (ppm) for the first time since observations began in 1958, according to new data.

Why it matters: Carbon dioxide is a long-lived, planet-warming greenhouse gas, the concentration of which is increasing due to human activities, such as the burning fossil fuels like coal and natural gas for energy. Studies show current levels are higher than any time in as long as 4.5 million years.

The big picture: Increasing amounts of CO2 in the atmosphere are boosting global average temperatures. Climate change has been conclusively tied to the escalating impacts from climate change, including more extreme and frequent heat waves, heavy precipitation events, larger, more frequent wildfires and sea level rise.

• Studies have shown that only steep emissions cuts beginning this decade can bring down CO2 levels sufficiently in order to meet the temperature targets laid out in the Paris Climate Agreement.

Zoom in: The new data, which comes from the Scripps Institution of Oceanography, shows that April had a monthly average CO2 concentration of 420.02 ppm. This is up from 316 ppm at the start of the Mauna Loa record.

• The National Oceanic and Atmospheric Administration (NOAA) will report its new numbers tomorrow, but they are expected to closely match the Scripps readings. The annual peak typically occurs in May, prior to the Northern Hemisphere warm season when vegetation soaks up the gas.
• "It is likely May will be higher still," Pieter Tans, who tracks greenhouse gases for NOAA, told Axios.

What they're saying: Looking at his agency's data and the trends from year-to-year and decade-to-decade, Tans said it's difficult to see any progress being made in bringing levels of global warming pollutants down.

• "The world effectively has made no serious progress compared to what is required," Tans said. "We really need to focus on decreasing emissions and we haven't had much success globally because the rate of increase of CO2 remains as high as it has been in the last decade."

• "Especially CO2 has a longevity of hundreds to thousands of years, so we are really making a very long-term climate commitment," Tans said.
• Tans and other researchers told Axios that the sustained year-to-year growth rates in CO2 concentrations are unprecedented. The 400 ppm mark was eclipsed less than a decade ago, in 2013, but CO2 amounts have increased by more than 2 ppm each year.

The bottom line: Technologies exist that would provide clean electricity, such as using solar and wind energy. Government and private sector funding is funneling into electric vehicles and technology that is farther off in development, like direct air capture, which would take carbon directly out of the atmosphere.

• However, so far, countries including the U.S. have yet to show results when it comes to stepping up the pace and ambition of cutting CO2 emissions.