Tuesday, February 15, 2022

Greenhouse gas levels keep rising at accelerating speed

Carbon dioxide

Carbon dioxide (CO₂) was 421.59 parts per million (ppm) at Mauna Lao, Hawaii, on February 14, 2022, a level unprecedented in millions of years. 

Carbon dioxide levels typically reach their annual maximum in May, so even higher levels can be expected over the next few months.

Carbon dioxide levels are even higher at high latitudes north. The image below shows that carbon dioxide levels are approaching 430 ppm at Barrow, Alaska.


NOAA's monthly global mean reading for October 2021 for methane (CH₄) is 1907.2 parts per billion (ppb), which is 17.1 ppb higher than the reading for October 2020. By comparison, NOAA's annual global mean methane increase of 15.74 ppb for 2020 was the highest on record at the time and the increase for 2021 looks to be even higher.
Keep in mind that NOAA's data are for marine surface measurements; more methane tends to accumulate at higher altitudes.

Furthermore, keep in mind that the above 1907.2 ppb reading is for October 2021; it now is February 2022.  The image below shows that recent methane levels are approaching 1940 ppb at Mauna Loa, Hawaii.

Similarly as carbon dioxide, methane levels are even higher at high latitudes north. Furthermore, the rise is accelerating strongly. At Barrow, Alaska, recent methane levels are approaching 2040 ppb. 

Nitrous oxide

The image below shows the annual increase in globally-averaged nitrous oxide (N₂O).

The top part of the combination image below shows IPCC scenarios for nitrous oxide, as discussed in an earlier post, with the bottom part showing recent NOAA observations (through to October 2022).

Clouds feedback

As discussed in an earlier post, just two greenhouse gases, carbon dioxide and methane, could abruptly cause the joint CO₂e to cross the 1200 ppm clouds tipping point, triggering a further 8°C global temperature rise, due to the clouds feedback.

Again, that could be the result of the climate forcing just of carbon dioxide and methane, without even adding further forcing such as by nitrous oxide. Meanwhile, as discussed, humans will likely go extinct with a 3°C rise, and a 5°C rise will likely end most life on Earth.


The situation is dire and calls for the most comprehensive and effective action, as described at the Climate Plan.


• NOAA - Mauna Loa, Hawaii

• NOAA - Barrow, Alaska

• Terrifying Arctic greenhouse gas levels continue
• NOAA - Nitrous oxide trends

• NOAA - Globally averaged marine surface monthly mean nitrous oxide data

• Is the IPCC creating false perceptions, again?

• Accelerating Methane Rise

• Terrifying Arctic greenhouse gas levels continue
• When Will We Die?