Arctic News: Water Vapor Feedback

Earth’s Energy Imbalance is now about four times as high as it was a decade ago, as illustrated by the above image, by Eliot Jacobson. As a result, feedbacks are starting to kick in with greater ferocity.

Water vapor feedback

One such feedback is the water vapor feedback. The temperature rise results in more evaporation, i.e. more water vapor and heat will enter the atmosphere, much of which will return to the surface in the form of precipitation, but some will remain in the atmosphere, as there will be 7% more water vapor for every 1°C warming. As illustrated by the image below, created with NOAA data, surface precipitable water was 27.181 kg/m² in August 2024, a record high for this month.

[ surface precipitable water through August 2024 ]

How much more water vapor currently is in the atmosphere compared to pre-industrial depends on how much the temperature has risen since pre-industrial. The February 2024 temperature was 1.76°C above 1885-1915, which could be as much as 2.75°C above the pre-industrial temperature. A 2.75°C rise corresponds with almost ⅕ more water vapor in the atmosphere.

More ocean heat and water vapor moving to Arctic

The temperature rise also comes with stronger wind. An earlier post points at a study that found increased kinetic energy in about 76% of the upper 2,000 meters of global oceans, as a result of intensification of surface winds since the 1990s.

Stronger wind speeds up ocean currents, enabling more ocean heat to move to the Arctic, while stronger wind also enables more water vapor to move to the Arctic and more rain to fall closer to the Arctic, along the path of prevailing ocean currents and wind patterns. As a result, both heat and water vapor will increase in the Arctic.

This will in turn further increase the temperature rise in the Arctic, since water vapor is a potent greenhouse gas, while more water vapor also results in less hydroxyl, thus extending methane’s lifetime.

The resulting temperature rise in the Arctic also reduces the snow and ice cover, further amplifying the temperature rise in the Arctic, while the temperature rise and the presence of more open water will also enable more evaporation, resulting in more water vapor in the atmosphere over the Arctic.

High levels of methane are already present over the Arctic and the water vapor feedback makes things worse. Additionally, more ocean heat entering the Arctic Ocean threatens to further destabilize sediments at the seafloor that contain methane hydrates and cause even more methane to erupt, resulting in huge amounts of methane entering the atmosphere over the Arctic, from the hydrates and also from free gas underneath the hydrates.

[ click on images to enlarge ]

More water vapor and rainfall combined with higher temperatures will also cause more methane releases from lakes, wetlands and permafrost on land in the northern parts of Canada, Europe and Siberia.

The image on the right shows a forecast by Climate Reanalyzer of high temperature anomalies in the northern parts of Europe on September 7, 2024.

The image below shows high methane levels forecast by Copernicus at surface level in northern Europe on September 7, 2024, 03 UTC (run 00 UTC).

As the image below shows, methane concentrations as high as 2400 parts per billion (ppb) were recently recorded at the NOAA observatory in Utqiagvik (Barrow), Alaska.

As Earth’s Energy Imbalance keeps rising, an increasing amount of heat accumulates in oceans. The image below, adapted from NOAA, illustrates the huge amount of heat present in the ocean around North America, with sea surface temperatures as high as 33.6°C (92.48°F) recorded on September 6, 2024. The image also shows the Gulf Stream (middle right), the Atlantic ocean current that carries heat from the Gulf of Mexico to the Arctic Ocean.

The image below, by Brian McNoldy shows that ocean heat content in the Gulf of Mexico was at record high on September 4, 2024.

The temperature rise is hitting the Arctic hard, as illustrated by the image below, created with NASA content.

The temperature rise in the air is most profound at both poles, a phenomenon known as polar amplification, as illustrated by the temperature anomaly map for August 2024 below.

Oceans are still absorbing an estimated 91% of the excess heat energy trapped in the Earth’s climate system due to human-caused global warming. If just a small part of that heat instead remains in the atmosphere, this could constitute a huge rise in temperature. Heat already stored in the deeper layers of the ocean will eventually be released, committing Earth to at least some additional surface warming in the future.

Polar amplification of the temperature rise causes a relative slowing down of the speed at which heat flows from the Equator to the poles. This impacts ocean currents and wind patterns, resulting in slowing down of the Atlantic meridional overturning circulation (AMOC) and of ocean currents around Antarctica that carry heat to the deep ocean, as well as in deformation of the Jet Stream.

A recent study warns about intensification of global warming due to the slowdown of the overturning circulation. The overturning circulation carries carbon dioxide and heat to the deep ocean, where it is stored and hidden from the atmosphere. As the ocean storage capacity is reduced, more carbon dioxide and heat are left in the atmosphere. This feedback accelerates global warming.

Warmer oceans also result in stronger stratification, which further contributes to make it harder for heat to reach the deeper parts of oceans. As a result, a larger proportion of heat that was previously entering oceans will instead remain in the atmosphere or accumulate at the ocean surface, and slowing down of the overturning circulation further contributes to this, as discussed above.

At the same time, overall global wind strength increases as temperatures rise, and as the Jet Stream gets more deformed, this can at times strongly boost the flow of wind and water along prevailing ocean currents, wind patterns and storm tracks that carry heat toward the Poles. Furthermore, polar amplification of the temperature rise results in a relatively stronger rise in water vapor in the air over Antarctica and the Arctic.

At times, part of this accumulated energy can, in the form of ocean heat and precipitable water, be abruptly transported to the Arctic, along the path of prevailing ocean currents and wind patterns boosted by stronger wind and storms. This is illustrated by the above image that shows unusually high amounts of precipitable water recorded near the North Pole on September 1, 2024, at 04 UTC (20 kg/m² at the green circle). This can be further facilitated by the formation of a freshwater lid at the surface of the North Atlantic that enables more ocean heat to travel underneath this lid to the Arctic Ocean.

Temperatures remain high

Temperatures remain high, even while a transition to La Niña is expected by Sep-Nov 2024, persisting through Jan-Mar 2025, as illustrated by the image below, adapted from NOAA.

The image below, from an earlier post and adapted from NOAA, illustrates that El Niño conditions were present from June 2023 through April 2024, and that ENSO-neutral started in May 2024. While El Niños typically occur every 3 to 5 years, as NOAA explains, El Niños can occur as frequently as every two years, as happened in 2002, 2004 and 2006, and as illustrated by the image below. The danger is that we could move into a new El Niño in 2025, while temperatures remain high due to feedbacks and while sunspots move toward a peak in this cycle, expected to occur in July 2025.

The image below illustrates that, for 14 consecutive months, the temperature anomaly has exceeded 1.2°C above 1951-1980 or (more aptly) 2°C above pre-industrial, and is rising again, even while El Niño ended April 2024.

Similarly, the image below illustrates that, for more than 14 consecutive months, the temperature anomaly has been high, i.e. about 0.8°C (± 0.3°C) above the 1991-2020 average and much more when compared to a pre-industrial base, with little or no sign of a return to earlier temperatures. On September 2, 2024, the temperature was 0.8°C above 1991-2020, the highest anomaly on record for that day of the year.

[ click on images to enlarge ]

The image below, created with NASA data while using a 1903-1924 custom base, illustrates that the monthly temperature anomaly through August 2024 has been more than 1.5°C above this base for each of the past consecutive 14 months, and even more when compared to a pre-industrial base. The red line shows the trend (2-year Lowess Smoothing) associated with the rapid recent rise.

A huge temperature rise could unfold by 2026, as the joint result of changes in the atmosphere, changes in surface and cloud albedo, changes in wind patterns & ocean currents, and further developments, e.g. in a cataclysmic alignment, a strong El Niño could develop in 2025 which, in combination with higher than expected sunspots, could make a difference of 0.75°C. Sunspots are expected to reach a peak in the current cycle in July 2025.

Sea ice disappearing fast

Sea ice is disappearing over large parts of the Arctic Ocean, including near the North Pole.

The above compilation image shows, on the left, that Arctic sea ice volume was at a record low for the time of year on September 5, 2024, as it has been for most of the year. On the right, an image by the University of Bremen showing sea ice concentration on September 5, 2024.

In the above compilation image, the NASA Worldview image on the left shows Arctic sea ice on September 10, 2024.

The Danish Meteorological Institute (DMI) image at the top right is from an earlier date, not yet showing the 2024 minimum, yet it does show that the minimum volume in earlier years was not as far below 5000 km³ as it was in 2024. The 2024 minimum is depicted on the DMI image on the bottom right, showing that Arctic sea ice volume was well below 5000 km³ on September 10, 2024.

In the above image the two DMI images overlap, highlighting that Arctic sea ice volume did reach a record low in 2024.

Global sea ice extent was 21.04 million km² on September 4, 2024, a record low for the time of year, as feedbacks start kicking in with greater ferocity, including less albedo, latent heat buffer and emissivity, more water vapor, less lower clouds, Jet Stream changes, more emissions, lightning and forest fires, stronger rainfall and heatwaves causing more run-off of heat, and stronger storms that can push ocean heat toward the poles, all contributing to accelerate sea ice loss and the temperature rise, as discussed in earlier posts such as this one.

A huge temperature rise could occur soon

As a result, several tipping points threaten to be crossed in the Arctic soon, as described in an earlier post, including the latent heat tipping point and a Blue Ocean Event (starting when Arctic sea ice extent will fall below 1 million km²), which would further speed up the temperature rise in the Arctic.

As temperatures keep rising in the Arctic, changes to the Jet Stream look set to intensify, resulting in loss of terrestrial albedo in the Arctic that could equal the albedo loss resulting from sea ice decline.

Further feedbacks include permafrost degradation, both terrestrial and on the seafloor of the Arctic Ocean, which looks set to cause huge releases of greenhouse gases (particularly CO₂, CH₄ and N₂O).

This would in turn also cause more water vapor to enter the atmosphere, further speeding up the temperature rise, especially in the Arctic, where vast amounts of methane are contained in sediments at the seafloor and where there is very little hydroxyl in the air to break down the methane.

Temperatures look set to rise further in the Arctic, due to falling away of sulfate aerosols, as illustrated by the IPCC image below that shows how much temperatures are currently suppressed in the Arctic due to aerosols and thus also shows how much temperatures in the Arctic look set to rise as the aerosol masking effect falls away.

Furthermore, the combined impact of aerosols and nitrogen fertilizers has been underestimated; a recent study concludes that when ammonia, nitric acid and sulfuric acid are present together, they contribute strongly to the formation of cirrus clouds.

At the same time, there could be a temperature rise due to releases of other aerosols that have a net warming impact, such as black and brown carbon, which can increase dramatically as more wood burning, forest fires and urban fires take place, which again would hit the Arctic hard by darkening the surface as they settle on the snow and ice cover, thus speeding up its decline.

The image below, with forecasts for September 9, 2024 03 UTC (run 00 UTC) adapted from Copernicus, illustrates gases and aerosols released due to forest fires burning in the Amazon.

The joint impact could cause the clouds tipping point to get crossed, adding an abrupt further 8°C to the rise, and altogether, a global temperature rise could unfold of more than 18°C above pre-industrial, as illustrated by the image further above on the right, and as also discussed at Extinction. This could in turn cause the water vapor tipping point to get crossed, which means that from then on the increase in water vapor alone would suffice to keep increasing the temperature, in a runaway greenhouse process in which evaporation could cause a global surface temperature rise of several hundred degrees Celsius and make our planet as inhospitable as Venus, as this study concludes and as discussed at this post.

[ click on images to enlarge ]

A 2020 study led by Jorgen Randers concludes that the world is already past a point-of-no-return for global warming, as self-sustained thawing of the permafrost will continue for hundreds of years, even if global society did stop all emissions of man-made greenhouse gases immediately, due to a combination of declining surface albedo (driven by decline of the Arctic snow and ice cover), increasing amounts of water vapor in the atmosphere (driven by higher temperatures), and changes in concentrations of further greenhouse gases in the atmosphere (driven by changes in sinks and sources of carbon dioxide and methane such as thawing permafrost), as illustrated by the image on the right, from an earlier post.

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.