Arctic News: thresholds

Showing posts with label thresholds. Show all posts

Saturday, July 13, 2024

Both Paris Agreement thresholds clearly crossed

Temperatures are rising

The NASA temperature anomaly vs. 1904-1924 shows that the temperature has been above 1.5°C for the past twelve months, as illustrated by the image below. The red line shows the trend (one-year Lowess Smoothing) associated with the rapid recent rise.

Note that the 1904-1924 base is not pre-industrial. When using a genuinely pre-industrial base, the temperature anomaly has over the past twelve months also been above the 2°C threshold that politicians at the 2015 Paris Agreement pledged wouldn't be crossed.

[ from earlier post ]

The above image, from an earlier post, shows that the February 2024 temperature was 1.76°C above 1885-1915, potentially 2.75°C above pre-industrial (bright yellow inset right). The image was created by Sam Carana for Arctic-news.blogspot.com with an April 2024 data.giss.nasa.gov screenshot. The red line (6 months Lowess smoothing) highlights the steep rise that had already taken place by then.

On July 21, 2024, a record high global temperature was reached of 17.09°C (62.76°F). The previous record, 17.08°C, was reached on July 6, 2023.

The next day, on July 22, 2024, the global surface air temperature reached 17.16°C (62.89°F), a new record high.

The image below shows that the sea surface temperature (60°S-60°N) was 20.9°C (69.62°F) on July 19, 2024, up from 20.82°C (69.48°F) on July 3, 2024. The question is whether the August 2024 sea surface temperatures will be higher than the peak reached in 2023.

The temperature at the North Pole was 0.1°C (32.3°F) on July 21, 2024, and is forecast to rise over the next few days.

Feedbacks

Higher temperatures come with feedbacks, as illustrated by the image below, from an earlier post.

As sea ice disappears, feedbacks accelerate the loss, including:

• Albedo loss - water is less reflective than ice (feedback #1)

• Loss of the latent heat buffer - as sea ice disappears, heat can no longer be consumed by the process of melting, and the heat will instead go into increasing the temperature (feedback #14)

• Emissivity - water is less efficient than ice in emitting in the far-infrared region of the spectrum (feedback #23)

• Water vapor and clouds - warmer water comes more water vapor and less low-level clouds that reflect sunlight back into space (feedback #25)

[ click on images to enlarge ]

Furthermore, decline of sea ice and permafrost is forecast to result in huge emissions of carbon dioxide, nitrous oxide and methane.

Permafrost decline also results in more meltwater in rivers. Heatwaves further heat up the water in rivers flowing into the Arctic Ocean. The image on the right shows sea surface temperatures as high as 20.2°C (68.36°F) in the Bering Strait on July 25, 2024.

• Deformation of the Jet Stream occurs as the Arctic heats up more rapidly than the rest of the world, which narrows the temperature difference between the Tropics and the Arctic, and this in turn changes the shape of the Jet Stream (feedback #19).

The Jet Stream will meander more and can at times even form circular wind patterns in some areas, which can strongly amplify extreme weather events such as storms that come with flooding and heatwaves, increasing their intensity, frequency, duration and area covered.

• On land, more extreme weather can cause strong rainfall, causing even stronger thawing of permafrost and more run-off of water into the Arctic Ocean (feedback #24).

• Storms and heatwaves further accelerate heating up of river water, causing a lot more heat to enter the Arctic Ocean (feedback #4).

[ click on images to enlarge ]

Additionally, deformation of the Jet Stream can at times speed up the flow of ocean heat toward the Arctic Ocean. Deformation of the Jet Stream enables strong winds to develop over the North Atlantic, which can in turn strongly accelerate the speed at which hot water is flowing toward the Arctic Ocean along path of the Gulf Stream. As a deformed Jet Stream speeds up this flow, huge amounts of ocean heat can abruptly be pushed from the North Atlantic into the Arctic Ocean in the path of the Gulf Stream.

The image on the right shows hot water getting pushed along the path of the Gulf Stream from the Gulf of Mexico toward the Arctic Ocean. The image shows sea surface temperatures as high as 32.9°C (91.22°F) on July 15, 2024.

The image below illustrates the huge amount of ocean heat present in the North Atlantic Ocean, with sea surface temperatures as high as 32.8°C (91.04°F) on July 29, 2024.

• Furthermore, a freshwater lid can form on top of the surface of the North Atlantic, enabling more hot water to flow underneath this lid into the Arctic Ocean (feedback #28).

• Eruptions of seafloor methane - as more heat reaches the seafloor of the Arctic Ocean, sediments and hydrates contained in them destabilize, resulting in methane releases (feedback #16)

Biochar needed to fight forest fires

Higher temperatures also come with greater forest fires hazards (feedback #9). Stronger drought and heatwaves and increased lightning further increase forest fire hazards. Forest fires result in emissions that cause black carbon to settle on ice, accelerating the temperature rise due to albedo loss and speeding up thawing of permafrost and melting of sea ice. The image below, adapted from Copernicus, shows a biomass burning aerosols forecast for July 22, 2024.

Forest fires contribute to the temperature rise in multiple ways, including:
• forest fires cause emissions that cause more heat to be trapped;
• forest fires contributed to the 2023 global net land carbon dioxide sink to be the weakest since 2003;

• forest fires reduce soil moisture content, which in turn reduces health and growth of vegetation and makes the land more vulnerable to erosion;
• forest fires cause emissions of black carbon that darkens the surface, resulting in less sunlight getting reflected back into space.

[ image from a 2014 post ]

The study into carbon sources and sinks, linked to above, refers to itself as an "analysis of the global carbon budget", which can give the wrong impression that it was healthy and sustainable to keep causing carbon emissions as long as the emissions were "compensated" by carbon taken up by land and ocean "sinks".

Similarly, the IPCC refers to a "carbon budget" as if there was an amount of carbon to be divided among polluters and to be consumed for decades to come.

The image on the right illustrates the fallacy of offsets. Instead, effective and comprehensive action is needed on multiple lines of action, simultaneously yet separately.

Indeed, action is needed to reduce concentrations of carbon both in oceans and in the atmosphere. On land, the soil carbon content needs to increase, which can be achieved by methods such as pyrolysis of biowaste and adding the resulting biochar to the soil, which will reduce fire hazards, sequester carbon and support the presence of moisture & nutrients in the soil and the health & growth of vegetation, as discussed at the Climate Plan group and the biochar group.

For more on feedbacks, see the feedbacks page.

Sea surface temperatures in the Northern Hemisphere

After an astonishing rise in 2023, sea surface temperature anomalies fell for six months in the Northern Hemisphere, but they are rising again, threatening to cause dramatic sea ice loss over the next few months and destabilize sediments at the seafloor, resulting in huge amounts of methane erupting and abruptly entering the atmosphere.

Rising sea surface temperatures are a major driver of sea ice loss.

Global sea ice extent takes a tumble

Higher temperatures result in more loss of sea ice. The image below shows that the global sea ice extent remained at a record low for the time of year on July 29, 2024.

The above image shows global sea ice extent at a record low for the time of year, after a huge fall from 22.45 million km² on July 9, 2024, to 21.08 million km² on July 29, 2024, as feedbacks start kicking in with greater ferocity, incl. 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.

The paragraph below is from an earlier post:
Sea ice loss results in less sunlight getting reflected back into space and instead getting absorbed by the ocean and the impact of Antarctic sea ice loss is even stronger than Arctic sea ice loss, as Antarctic sea ice is located closer to the Equator, as pointed out by Paul Beckwith in a video in an earlier post. A warmer Southern Ocean also comes with fewer bright clouds, further reducing albedo, as discussed here and here. For decades, there still were many lower clouds over the Southern Ocean, reflecting much sunlight back into space, but these lower clouds have been decreasing over time, further speeding up the amount of sunlight getting absorbed by the water of the Southern Ocean, and this 'pattern effect' could make a huge difference globally, as this study points out. Emissivity is a further factor; open oceans are less efficient than sea ice when it comes to emitting in the far-infrared region of the spectrum (feedback #23 on the feedbacks page).

[ click on images to enlarge ]

The temperature rise comes with sea ice decline and feedbacks, as illustrated by the above image.

A. Higher temperatures cause sea ice decline and feedbacks, including deformation of the Jet Stream, due to narrowing of the temperature difference between the Poles and the Tropics.

B. At times, the Jet stream can move over Antarctica, bringing along warmer air.

C. This can result in anomalies of over 30°C, further accelerating sea ice decline.

D. Higher temperatures can also cause warm air to rise up into the stratosphere, where it can be -16.5°C near Australia (green circle).

Arctic sea ice

The image below, adapted from the Danish Metereological Institute, indicates that Arctic sea ice volume is at a record low for the time of year, as it has been for most of the year. At the same time, Arctic sea ice extent is not the lowest on record for the time of year; on July 25, 2024, Arctic sea ice extent was third lowest on record, extent was lower only in 2019 and 2020 of all years on record. See discussion at facebook. The implication is that sea ice must be very thin.

The image below, adapted from the University of Bremen, shows Arctic sea ice thickness on July 19, 2024.

The above images shows that most of the thicker Arctic sea ice has melted, i.e. the latent heat buffer has virtually disappeared. This and further feedbacks and events (e.g. high sunspots) may cause temperatures to keep rising, even while La Niña is expected to prevail in Aug-Oct 2024. The screenshot below, from an earlier post, further illustrates the danger.

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.