Carbon dioxide (CO₂) concentrations grew by 3.75 parts per million (ppm) during 2024, the highest growth rate on record.
The annual global average surface concentration of CO₂ for 2024 was 422.79 ppm, according to NOAA data.
The image below shows the monthly global average surface concentration of CO₂ through January 2025.
Meanwhile, concentrations of CO₂ have exceeded 430 ppm for six days in a row at Mauna Loa, Hawaii, as illustrated by the image below.
The image below shows a trend based on 2019-2025 annual NOAA data that points at 1200 ppm CO₂ getting crossed in 2030.
The above trend illustrates how the clouds tipping point could get crossed in 2030 due to rising CO₂ alone, crossing this tipping point on its own could push temperatures up by 8°C, in addition to the rise caused by the extra CO₂ to reach the tipping point. The clouds tipping point is actually at 1200 ppm CO₂e (carbon dioxide equivalent), so when taking into account growth of other greenhouse gases and further mechanisms, the tipping point could be crossed much earlier than in 2030.![]() |
[ from earlier post, note the recent discussion on monthly methane ] |
While using different periods and types of trends can result in trends that don't show such a steep rise, the point is that such a steep rise in N₂O could eventuate, based on recent data. The rise could become even steeper, given that N₂O emissions caused by people come mainly from applying nitrogen fertilizers and animal waste to farmland and pastures, and that policy control over emissions from nitrogen fertilizers is largely absent or ineffective, while farmers are increasingly using nitrogen fertilizers in efforts to increase crop yield, especially where yields are falling due to rising temperatures and more extreme weather events.
IPCC AR6 gives N₂O a global warming potential (GWP) of 273 over both 500 years and 100 years, and of 118 over 20 years, while its lifetime is 120 years. Furthermore, N₂O is currently the most significant ozone depleting substance (ODS) being emitted. The impact of N₂O as ODS has grown strongly over the years, relative to other ODS. Nitrogen fertilizers are typically produced with natural gas, thus further driving up concentrations of methane in the atmosphere. For better approaches, have a look at this 2022 post.
The Arctic is hit most strongly by the temperature rise, as illustrated by the image below showing the ERA5 global temperature anomaly for February-March 2025 versus 1951-1980.
Conditions are dire. Temperatures and concentrations of greenhouse gases are high and rising fast, sea ice is disappearing, sunspots are reaching their peak in this cycle and a new El Niño may emerge soon.
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[ Arctic sea ice volume, click to enlarge ] |
As the likeliness of a huge and accelerating temperature rise, the severity of its impact, and the ubiquity and the imminence with which it will strike all become more manifest—the more sobering it is to realize that a mere 3°C rise may suffice to cause human extinction.
Climate Emergency Declaration
The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.
Links
• NOAA - Global averaged marine surface annual mean carbon dioxide data
https://gml.noaa.gov/webdata/ccgg/trends/co2/co2_annmean_gl.txt
• NOAA - Annual Mean Global Carbon Dioxide Growth Rates
discussed on facebook at:
https://www.facebook.com/groups/arcticnews/posts/10162561012229679
• NOAA - Nitrous oxide emissions grew 40 percent from 1980 to 2020, accelerating climate change
• N₂O is currently the most significant ozone-depleting substance being emitted
• NOAA - ENSO: Recent Evolution, Current Status and Predictions - 14 April 2025
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf
• Danish Meteorological Institute - Arctic sea ice volume and thickness
https://ocean.dmi.dk/arctic/icethickness/thk.uk.php
• Transforming Society
https://arctic-news.blogspot.com/2022/10/transforming-society.html
• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html
• Climate Emergency Declaration
https://arctic-news.blogspot.com/p/climate-emergency-declaration.html