Global carbon dioxide increased to highest levels in May 2022: NOAA

According to the National Oceanic and Atmospheric Administration (NOAA), the main US climate agency, concentrations of CO2 in the atmosphere in May this year were 50 percent higher than during the pre-industrial era, reaching levels not seen on Earth for about four million years.

The global warming caused by humans – through the production of electricity using fossil fuels, transport, the production of cement, or even deforestation – is believed to be responsible for the new high.

May is usually the month with the highest carbon dioxide levels each year, but in May 2022, the threshold of 420 parts per million (ppm) – a unit of measurement used to quantify pollution in the atmosphere – was crossed.

Before the Industrial Revolution, levels of CO2 held steady at around 280 ppm, a level maintained for approximately 6,000 years of human civilization that preceded industrialization, according to NOAA.

The level now is comparable to what it was between 4.1 and 4.5 million years ago, when CO2 levels were near or above 400 ppm according to the study.

The measurements are taken at the Mauna Loa observatory in Hawaii, ideally located high on a volcano, which allows it to escape the possible influence of local pollution.