Daily carbon dioxide crosses 430 ppm

[ Temperature anomaly through February 2025 ]

The above image shows that monthly temperature anomalies have been more than 1.5°C above 1903-1924 (custom base, not pre-industrial) for 20 consecutive months (July 2023 through February 2025).

The temperature anomaly is rising rapidly, the red line (2-year Lowess Smoothing trend) points at a 2°C rise in 2026 (compared to 1903-1924, which - as said - is not pre-industrial).


As the above image shows, the February 2025 temperature anomalies were particularly high over the Arctic, as high as 11.7°C and reflecting very high temperatures of the water of the Arctic Ocean. This is a very dangerous situation, as discussed elsewhere in this post. 

The image below confirms the very high Arctic temperature anomalies in February 2025. 

The image below illustrates the threat of a huge temperature rise. The red trend warns that the temperature could increase at a terrifying speed soon. The global surface air temperature was 13.87°C on March 8, 2025, the highest temperature on record for this day. This is the more remarkable since this record high temperature was reached during a La Niña. 

The shading in the above image highlights the difference between El Niño conditions (pink shading) and La Niña conditions (blue shading). An El Niño pushes up temperatures, whereas La Niña suppresses temperatures. We're currently in a La Niña, so temperatures are suppressed, but this is predicted to end soon. NOAA predicts a transition away from La Niña to occur next month.

The transition from La Niña to El Niño is only one out of ten mechanisms that could jointly cause the temperature rise to accelerate dramatically in a matter of months, as described in a previous post. Another one of these mechanisms is the increase in greenhouse gas concentrations. 

Increase in carbon dioxide 

The daily average carbon dioxide (CO₂) at Mauna Loa, Hawaii, was 430.60 parts per million (ppm) on March 7, 2025, the highest daily average on record. To find higher levels, one needs to go back millions of years. 

Carbon dioxide typically reaches its annual maximum in May, which means that even higher daily averages can be expected over the next few months. The image below shows that this reading of 430.6 ppm at Mauna Loa is way higher than the highest daily averages recorded in 2024. 

 

The image below shows the daily average for March 7, 2025, marked in blue and with an arrow pointing at it. The image shows that weekly averages are also at a record high, 428.1 ppm, higher than the highest weekly average in 2024. The monthly average for February 2025 was 427.09 ppm, higher than the highest monthly average in 2024. 

The annual increase in CO₂ at Mauna Loa, Hawaii, is accelerating, as illustrated by the image below. 

[ click on images to enlarge ]

A trend, based on 2015-2024 annual data, points at 1200 ppm CO₂ getting crossed in the year 2032, as illustrated by the image below.

[ from an earlier post ]

The above trend illustrates that the clouds tipping point could get crossed in early 2032 due to rising CO₂ alone, which on its own could push temperatures up by an additional 8°C. The clouds tipping point is actually at 1200 ppm CO₂e, so when growth of other greenhouse gases and further mechanisms is taken into account, the tipping point could be crossed much earlier than in 2033.

Increase in methane

Methane in the atmosphere could be doubled soon if a trend unfolds as depicted in the image below. A rapid rise is highlighted in the inset and reflected in the trend. 

[ from earlier post ]

The trend is based on 22 consecutive global monthly averages as calculated by NOAA (from January 2023 through October 2024) and has a R-squared value of 1, indicating that the trend constitutes a perfect fit of the data.

The period of 22 months was selected as the resulting trend strongly reflects the steep rise in methane that took place over the four most recent months for which data are available (as highlighted in the inset on the image). One could argue that seasonal variations could reduce the growth over the coming months, but on the other hand, a huge rise in methane could occur soon due to eruptions of methane from clathrates at the seafloor of the Arctic Ocean.

The trend points at a doubling of methane by March 2026. If the trend would continue, methane concentrations in the atmosphere would by September 2026 increase to more than triple the most recent value, and would increase to more than fourfold the most recent value by the end of 2026.

A rise like the one depicted in the trend could eventuate as rising ocean heat destabilizes methane hydrates contained in sediments at the seafloor of the Arctic Ocean. The temperature rise in the Arctic would accelerate since the methane would have a huge immediate impact on temperatures over the Arctic and cause depletion of hydroxyl, of which there is very little in the atmosphere over the Arctic in the first place. Such a rise in methane would also dramatically increases in tropospheric ozone and in stratospheric water vapor. A large increase in methane over the Arctic would also trigger massive wildfires and devastate terrestrial permafrost, resulting in huge amounts of further emissions.

Sea ice loss

At the moment, more sunlight reaches the Southern Hemisphere than the Northern Hemisphere. Consequently, low sea ice on the Southern Hemisphere results in a lot less sunlight getting reflected back into space and a lot more sunlight instead getting absorbed by the surface globally. 

The image below illustrates that global sea ice area has been at a record daily low since the start of February 2025. 

[ Arctic sea ice extent, click to enlarge ]

Sea ice extent is the total region with at least 15% sea ice cover. Sea ice extent can include holes or cracks in the sea ice and melt ponds on top of the ice, all having a darker color than ice. Sea ice area is the total region covered by ice alone. Sea ice area (image below) is a more critical measure in regard to albedo than sea ice extent (image on the right), so it makes sense to look at sea ice area, rather than at sea ice extent.

Over the next few months, the state of Arctic sea ice will become progressively more important regarding reflectivity, as progressively more sunlight will reach the Northern Hemisphere with the change in seasons. The temperature of the water of the Arctic Ocean could rise dramatically due to low Arctic sea ice. 

[ Arctic sea ice volume, click to enlarge ]

Warmer water flowing into the Arctic Ocean causes Arctic sea ice to shrink not only in extent and area, but even more so in thickness and thus volume, diminishing its capacity to act as a buffer that consumes ocean heat entering the Arctic Ocean from the North Atlantic and from the Pacific Ocean.

As sea ice thickness decreases, less incoming ocean heat can be consumed by melting the sea ice from below, while ocean heat is rising. An increasing proportion of the incoming ocean heat will therefore contribute to higher temperatures of the water of the Arctic Ocean. There is a point beyond which the rise in ocean heat will accelerate dramatically.

[ from Albedo, latent heat, insolation and more ]

Similarly, there is a point beyond which thawing of permafrost on land and melting of glaciers can no longer consume heat, and all further heat will instead warm up the surface.

[ from earlier post ]

The Sun will reach its most northerly position on June 21, 2025 (Solstice). Around this time of year, the sunlight has less distance to travel through the thinner atmosphere over the Arctic, so less sunlight gets absorbed or scattered before reaching the surface.

[ from Insolation ]

In addition, the high angle of the Sun produces long days, while the sunlight is also concentrated over a smaller area. Above the Arctic Circle, the Sun does not set at this time of year, so solar radiation continues all day and night. During the months of June and July, insolation over the Arctic is higher than anywhere else on Earth.

Further mechanisms

 
Another mechanism is sunspots, which are predicted to reach a peak in this cycle in July 2025 and sunspots to date in this cycle are higher than predicted. 

Yet another mechanism is reductions in cooling aerosols. According to James Hansen et al. (2023), reductions in cooling aerosols from shipping may well be responsible for much of the acceleration in the recent rise in temperature and the increase in the Earth's Energy Imbalance.

For more on mechanisms, see also the earlier post Mechanisms behind a steep rise in temperature. 

Climate Emergency Declaration

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective climate 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

• NASA - Goddard Institute for Space Studies - surface temperature
https://data.giss.nasa.gov/gistemp

• Climate Reanalyzer
https://climatereanalyzer.org

• pre-industrial
https://arctic-news.blogspot.com/p/pre-industrial.html

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• Global surface air temperature
https://pulse.climate.copernicus.eu

• NOAA - Global Monitoring Laboratory - monthly trends in CO₂
https://gml.noaa.gov/ccgg/trends/monthly.html

• NOAA - Global Monitoring Laboratory

https://gml.noaa.gov/dv/iadv/graph.php?code=MLO&program=ccgg&type=ts

• Clouds tipping point
https://arctic-news.blogspot.com/p/clouds-feedback.html

• Kevin Pluck - seaice.visuals.earth
https://seaice.visuals.earth

• NSIDC - National Snow and Ice Data Center
https://nsidc.org

• Danish Meteorological Institute - Arctic sea ice volume and thickness
https://ocean.dmi.dk/arctic/icethickness/thk.uk.php

• Albedo
https://arctic-news.blogspot.com/p/albedo.html

• Insolation
https://arctic-news.blogspot.com/p/insolation.html

• Sunspots
https://arctic-news.blogspot.com/p/sunspots.html

• Global warming in the pipeline - by James Hansen et al. (2023)

https://academic.oup.com/oocc/article/3/1/kgad008/7335889

• Carbon dioxide growing rapidly
https://arctic-news.blogspot.com/2024/08/carbon-dioxide-growing-rapidly.html

• Double Blue Ocean Event 2025?
https://arctic-news.blogspot.com/2024/10/double-blue-ocean-event-2025.html

• Did a Terminal Temperature Acceleration Event start in December 2024?
https://arctic-news.blogspot.com/2024/12/did-a-terminal-temperature-acceleration-event-start-in-december-2024.html

• 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

Temperature Rise

Record High Temperatures in 2014

The year 2014 was the warmest year across global land and ocean surfaces since records began in 1880, writes NOAA, adding the graph below. This graph illustrates that temperatures have risen even when focusing on a relatively short recent period with a linear trendline starting in 1998, which was an El Niño year, whereas 2014 wasn't.

Source: NOAA Global Analysis - Annual 2014

Most Appropriate Trendline

While the purple 1998-2014 trendline serves the useful purpose of dispelling the myth that warming had halted recently, it isn't the most appropriate trendline, since extending this trendline backward to 1880 would leave too many data too remote from the trendline, as is further illustrated by the animated image below.

What about the blue linear trendline that is based on data for all the years from 1880 to 2014? By that same logic, the appropriateness of this trendline must also be questioned. Temperatures in recent years have been well above this trendline. A polynomial trendline seems a much better fit, as illustrated by the image below.

Above image also extends the trendline forward, showing that 2 degrees Celsius warming looks set to be exceeded in 2038, based on the same data.

And while this is a frightening scenario, the picture may well be much too optimistic, because the heat is felt most in the Arctic Ocean, the very location where some of the most terrifying feedbacks are accelerating local warming, as further explained below.

Feedbacks in the Arctic

As NOAA writes, much of the record warmth for the globe can be attributed to record warmth in the global oceans, which reached the highest temperature among all years in the 1880–2014 record.

As above image shows, ocean heat reached a record high in 2014. In other words, it was ocean heat that pushed the combined ocean and land temperature to a record high. Anomalies were especially high in the Arctic Ocean, as illustrated by the image below.

Waters close to Svalbard reached temperatures as high as 63.5°F (17.5°C) on September 1, 2014 (green circle). Note that the image below shows sea surface temperatures only. At greater depths (say about 300 m), the Gulf Stream is pushing even warmer water through the Greenland Sea than temperatures at the sea surface.

Since the passage west of Svalbard is rather shallow, a lot of this very warm water comes to the surface at that spot, resulting in an anomaly of 11.9°C. The high sea surface temperatures west of Svalbard thus show that the Gulf Stream can carry very warm water (warmer than 17°C) at greater depths and is pushing this underneath the sea ice north of Svalbard.

Planetary energy imbalance (0.6 W/m2) equals the amount of energy in exploding 400,000 Hiroshima atomic bombs per day, 365 days/year (J. Hansen, 16 Jan. 2015).

Planetary imbalance now is 0.6 W/m². This has made the rise in ocean heat (up to 2000 m deep) more than double over the past decade. Data from 2005 through to 2014 contain a polynomial trendline that points at a similar rise by 2017, followed by an even steeper rise.

What could cause such non-linear rise?

The answer is feedbacks. Arctic snow and ice loss alone may well cause over 2 W/m² warming, warns Prof. Peter Wadhams. Another such feedback is methane erupting from the ocean floor, as methane hydrates get destabilized due to higher temperatures.

As illustrated by the graph below, most of this excess heat is absorbed by oceans and ice. Some of the heat is consumed by the process of melting ice into water, and 93.4% of this excess heat ends up warming up the oceans.

Graph by Sceptical Science based on study by by Nuccitelli et al.

As the Gulf Stream keeps carrying ever warmer water into the Arctic Ocean, methane gets released in large quantities, as illustrated in the images below showing high methane levels over the East Siberian Arctic Shelf (red oval left) and over Baffin Bay (red oval right) with concentrations as high as 2619 ppb.

click on image to enlarge

The images below show methane levels on Jan 25 (top), and Jan 26, 2015 (bottom).

The threat is that huge amounts of methane will erupt from the seafloor of the Arctic Ocean over the coming decades, as illustrated by the image below.

For more on this image, see this post and this page.

Demise of the Arctic sea ice and snow cover is another terrifying feedback. The image below features a NASA/Goddard Space Flight Center Scientific Visualization Studio screenshot showing decline of multi-year Arctic sea ice area over the years.

Below is a video by Nick Breeze who interviews Professor Peter Wadhams on multi-year Arctic sea ice.

An exponential trendline based on sea ice volume observations shows that sea ice looks set to disappear in 2019, while disappearance in 2015 is within the margins of a 5% confidence interval, reflecting natural variability. In other words, extreme weather events could cause Arctic sea ice to collapse as early as 2015, with the resulting albedo changes further contributing to the acceleration of warming in the Arctic and causing further methane eruptions from the seafloor of the Arctic Ocean.

click on image to enlarge

As the Arctic continues to warm, the temperature difference between the equator and the Arctic declines, resulting in changes to the jet streams and polar vortex.

One such change is a slowing down of the speed at which the jet streams and polar vortex circumnavigate the globe, as discussed in a recent post.

The image on the right shows that the jet streams on the Northern Hemisphere reached speeds as high as 410 km/h (255 miles per hour) on January 9, 2015. Also note the jet stream crossing the Arctic Ocean, rather than staying between 50 and 60 degrees latitude, where the polar jet streams used to be.

The image below shows winds on January 11, 2015, at several altitudes, i.e. at 10 hPa | ~26,500 m (16.5 mile), high in stratosphere, polar vortex (left, at 250 hPa | ~10,500 m (6.5 mile), jet stream (center), and at 700 hPa | ~3,500 m (2.2 mile), high in planetary boundary layer.

click on image to enlarge

As a result, extreme weather events such as heatwaves and storms can be expected to occur with greater frequency and intensity, as also discussed in a recent post. Heatwaves can heat up the water in the North Atlantic, as it flows into the Arctic Ocean, driven by the Gulf Stream, while heatwaves can also warm up the water in rivers that end up in the Arctic Ocean. Heatwaves can also hit the sea ice in the Arctic Ocean directly, causing rapid sea ice melting, while storms can make the ice break up and be driven out of the Arctic ocean,

Demise of the sea ice and snow cover in the Arctic results in further acceleration of warming, not only due to less sunlight getting reflected back into space, but also due to loss of the buffer that currently absorbs huge amounts of heat as it melts in summer. With the demise of this latent heat buffer, more sunlight will instead go into heating up the water of the Arctic Ocean. For more on the latter, see the page on latent heat.

Above image illustrates some of the self-reinforcing feedback loops that have been highlighted in this and earlier posts. Further feedbacks are pictured in the image below.

from the Feedbacks page

Runaway Global Warming

Above feedbacks are already pushing the temperature rise in the Arctic through the 2°C guardrail.

Based on existing temperature data, global warming on land looks set to exceed 2°C (3.6°CF) warming by the year 2034, but methane eruptions from the seafloor of the Arctic Ocean could push up global temperature rise even faster, in a runaway global warming scenario.

click to enlarge image

This raises the specter of human extinction. With no action taken, there appears to be a 55% risk that humans will be extinct by the year 2045, while taking little action will only postpone near-term human extinction by a few years. Only with rapid implementation of comprehensive and effective action may we be able to avoid this fate.

Comprehensive and Effective Action

In conclusion, the situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog at climateplan.blogspot.com and as illustrated by the image below.

Record June–August Global Ocean Surface Temperature

August 2014 record high land and ocean temperature

The combined average temperature across global land and ocean surfaces for August 2014 was record high for the month, at 0.75°C (1.35°F) above the 20th century average of 15.6°C (60.1°F).

June–August 2014 record high land and ocean temperature

June–August 2014, at 0.71°C (1.28°F) higher than the 20th century average, was the warmest such period across global land and ocean surfaces since record keeping began in 1880.

August 2014 record high sea surface temperature

The August global sea surface temperature (SST) was 0.65°C (1.17°F) above the 20th century average of 16.4°C (61.4°F). This record high departure from average not only beats the previous August record set in 2005 by 0.08°C (0.14°F), but also beats the previous all-time record set just two months ago in June 2014 by 0.03°C (0.05°F).

June–August 2014 record high sea surface temperature

The June–August global ocean surface temperature was 0.63°C (1.13°F) above the 20th century average, the highest on record for June–August. This beats the previous record set in 2009 by 0.04°C (0.07°F).

John Davies comments: 

This was the warmest August on record, primarily due to very high Sea Surface Temperatures in the Northern Hemisphere.

There is no El Nino event in this period, but some sort of event - hopefully an event not a climate shift - is taking place. If this is an event, the situation will become more normal when it ends, which will be in less than a years time at worst. If it is a climate shift, we are in desperate trouble, though I think it is an event.

It is worth noting that these very high Sea Surface Temperatures are likely to lead to high land temperatures soon, as normally land temperatures in the Northern hemisphere can be expected to exceed Sea Surface Temperatures.

The drought affecting California and the whole of the west of North America, Central America, and large parts of the Brazilian rainforest, though preceding this event was almost certainly down to changes which started before this event but ultimately caused it.

Despite the record high combined average temperature across global land and ocean surfaces for August, the global economy will continue as normal and no specific action can be expected to be taken to curb emissions. This will change, if global temperatures continue to rise. Temperatures are high enough to cause global concern, however. More later.

Note: NOAA's most recent (Sep 4, 2014) prediction puts the chance of El Niño at 60-65% during the Northern Hemisphere fall and winter.

Sea surface temperatures (SST) can be expected to remain high in the Arctic Ocean, as SST anomalies are high in the North Atlantic (+1.65°C, image left) and high temperatures are forecast over the Arctic for at least the next seven days (anomalies as high as +2.87°C, image right). For a comparison with October 3 temperatures, see this earlier post.

Additionally, an increasing amount of heat has been going into the deeper parts of the ocean, and the Gulf Stream will for month to come continue to transport water into the Arctic Ocean, and this water will be warmer than the water already there, threatening to unleash ever larger eruptions of methane from the seafloor of the Arctic Ocean, as discussed in this earlier post.

In conclusion, the situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog.


References

- NOAA National Climatic Data Center, State of the Climate: Global Analysis for August 2014.
http://www.ncdc.noaa.gov/sotc/global/2014/8

- EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION, issued by:
Climate Prediction Center/NCEP/NWS and the International Research Institute for Climate and Society, 4 September 2014
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.pdf

- ENSO: Recent Evolution, Current Status and Predictions
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

- ClimateReanalyzer.org
http://climatereanalyzer.org

The Threat of Storms Wreaking Havoc in the Arctic Ocean

Arctic sea ice extent is close to a record low for the time of the year, as the image below shows.

Furthermore, the current decline in sea ice extent is much steeper than it used to be for this time of the year, raising the specter of sea ice hitting an absolute record low later this year. Moreover, a total collapse of sea ice may occur if storms continue to develop that push the remaining ice out of the Arctic Ocean into the Atlantic Ocean.

The threat posed by storms is illustrated by the track projected to be followed by Hurricane Arthur (above NOAA image, July 4), renamed as Post-Tropical Cyclone Arthur (NOAA image below, July 5).

The path followed by Arthur is influenced by the current shape of the jet stream. As the animation below illustrates, the jet stream looks set to prevent Hurrican Arthur from moving to the east and instead make it move into the Labrador Sea to the west of Greenland and - partly due to the high mountains on Greenland - continue to wreak havoc in Baffin Bay further north.

[ Note: this animation is a 1.87 MB file that may take some time to fully load ]

As described in an earlier post, post-tropical cyclone Leslie made landfall with hurricane-force winds in Newfoundland in September 2012. The large extratropical low pressure system continued to move rapidly northeastward across eastern Newfoundland at a forward speed of near 45 kt, and merged with a much larger extratropical low over the Labrador Sea.

Recent research by NOAA-affiliated scientists suggests that - over the years - the latitude where hurricanes, typhoons, and cyclones reach their maximum intensity on the Northern Hemisphere has shifted closer to the North Pole.

Such storms can bring lots of heat and moisture into the Arctic, and they can also increase the height of waves. All this can have devastating impact on the sea ice. The many ways in which storms can increase the dangerous situation in the Arctic is described in the post Feedbacks in the Arctic.

Last month, the June heat record broke in Greenland. Very high temperatures are currently recorded all over North America, as the image below shows.

Furthermore, sea surface temperature anomalies in the Arctic are currently very high, as the image below shows.

Additionally, the sea ice is currently very thin, as shown by the Naval Research Laboratory animation below.

The above animation further shows that there now is very little sea ice left in Baffin Bay, making it easier for storms to cause very high waves that could enter the Arctic Ocean and break the sea ice north of Greenland and Canada.

Arctic sea ice volume minimum is typically reached around halfway into September. This is still months away, but the prospect of an El Niño event striking this year now is 90%, according to predictions by the European Centre for Medium-range Weather Forecasts.

All this combines into a growing threat that hydrates contained in sediments will destabilize and that huge quantities of methane will be released abruptly from the seafloor of the Arctic Ocean. The risk that this will eventuate is intolerable and calls for parallel lines of action as pictured in the image below.

Climate Plan, July 7, 2014 version, as discussed at this Climate Plan post and at the Climate Plan blog

Related

- Storm enters Arctic region
arctic-news.blogspot.com/2012/09/storm-enters-arctic-region.html

- Huge cyclone batters Arctic sea ice
arctic-news.blogspot.com/2012/08/huge-cyclone-batters-arctic-sea-ice.html

- Hurricane Sandy moving inland
http://arctic-news.blogspot.com/2012/10/hurricane-sandy-moving-inland.html

- Feedbacks in the Arctic
http://arctic-news.blogspot.com/2014/03/feedbacks-in-the-artcic.html