Figures presented by NOAA (National Oceanic and Atmospheric Administration) in the USA show that the CO₂ level in the atmosphere passed a “dramatic limit” last year.

The CO₂ level in the atmosphere last year was 417.06 ppm (parts per million), which is estimated to be more than 50 percent higher than it was in pre-industrial times (1850–1900).

50 per cent more than pre-industrial times is to some extent an artificial milestone, but it is nevertheless a very important milestone, says climate researcher Bjørn Samset at Cicero to NRK.

CO₂ levels increased by 2.13 ppm in 2022. This is the fourth highest increase ever.

These measurements are the reality that gives us a small slap in the face, says Samset.

The last eleven years have all had ppm increases of over 2.0, some of which have not previously been recorded in the 65 years of measurement by the NOAA.

It is the next step in a very dramatic development that we have seen over a long time; there are more greenhouse gases with every passing year, says Samset.

The amount of methane in the atmosphere also increased sharply in 2022, and the concentration of methane in the atmosphere is now two and a half times higher than in pre-industrial times.

Here, however, the researchers admit that they do not know why the amount of methane in the atmosphere is increasing.

For methane, we are not quite sure why the concentration rises as quickly as it does, says Samset, and adds:

When we add all that up and look at how much nature takes up, the increase in methane should really have been a little lower. So there is something here that we have not fully understood.

NOAA writes that the concentration of CO₂ in the atmosphere is now as high as it was in the Pliocene epoch around 4.3 million years ago.

There is now an extremely large amount of greenhouse gases in the atmosphere compared to what it was. Far, far beyond anything we humans have seen throughout our entire existence as a species, says Samset.

It is caused by us. It has gone very, very fast and we know from past climates how dramatically different conditions were the last time there were such large amounts of greenhouse gases in the atmosphere, he adds.

What Samset does not attach much importance to is the fact that 4.3 million years ago the temperature was almost 4 degrees warmer than today, and the sea level was approximately 23 metres higher.

Even if the conditions will not be as they were many millions of years ago, it is a pointer to how big changes we can now expect, concludes the climate researcher.