The amount of planet-warming carbon dioxide in Earth’s atmosphere has hit a new record as humanity struggles to curb greenhouse gas emissions from burning fossil fuels.
The new record comes as tens of millions of people are braving extreme weather in the United States. Much of the western US is experiencing the first heat wave of the year, which is making temperatures 20 to 30 degrees Fahrenheit hotter than what is normal for June. In the Southwest, temperatures are well over 100 degrees.
Such extreme and prolonged heat is directly linked to human-caused climate change, scientists say. All the extra carbon dioxide (CO2) in the atmosphere traps heat and leads to more intense, frequent and persistent heat waves and other extreme weather, such as powerful hurricanes and heavy rainstorms.
“Over the past year, we’ve experienced the hottest year on record, the hottest ocean temperatures on record and a seemingly endless string of heat waves, droughts, floods, wildfires and storms,” ​​said Rick Spinrad, administrator of National Oceanic. and National Atmospheric Administration (NOAA), in a statement. “We need to recognize that these are clear signals of the damage that carbon dioxide pollution is doing to the climate system and take swift action to reduce our use of fossil fuels as soon as we can.”
The concentration of carbon dioxide in the atmosphere is measured in parts per million, and the measurements were taken at an observatory in Hawaii. In May, atmospheric CO2 concentrations peak because the gas accumulates more in the winter months when there are fewer leaves worldwide to absorb it.
This May, the concentration of CO2 in the atmosphere reached about 427 parts per million, which is an increase of about 3 parts per million compared to last year’s peak. This is one of the largest annual jumps on record, scientists say.
The vast majority of planet-warming pollution in the atmosphere comes from humans burning fossil fuels such as oil, gas and coal.
The amount of carbon dioxide in the atmosphere has risen steadily since scientists began routine measurements in 1958. At the time, the concentration of CO2 in the atmosphere was 313 parts per million, slightly higher than in the 19th century. when the Industrial Revolution sparked widespread consumption of fossil fuels.
But in recent years, the increase in CO2 in the atmosphere has accelerated. In the first four months of this year, CO2 concentrations rose faster than during the first four months of any previous year, according to scientists at NOAA and the Scripps Institution of Oceanography at the University of San Diego.
Although routine, direct measurements of CO2 in the atmosphere began in the 1950s, scientists are able to use other methods to estimate how much carbon dioxide was in the atmosphere millions of years ago. And there is more carbon dioxide now than there has been in millions of years.
Rising CO2 levels underscore the extent to which humanity’s collective efforts to reduce greenhouse gas emissions and switch to renewable energy sources are falling short of what is needed to curb global temperatures. In the US, greenhouse gas emissions fell slightly last year, but those declines don’t put the country on track to meet the climate goals set by the Biden administration.