Showing posts with label temperature anomaly. Show all posts
Showing posts with label temperature anomaly. Show all posts

Friday, January 15, 2021

2020: Hottest Year On Record

NASA data show that 2020 was the hottest year on record.

The image below shows that high temperature in 2020 hit Siberia and the Arctic Ocean.

In above images, the temperature anomaly is compared to 1951-1980, NASA's default baseline. When using an earlier baseline, the data need to be adjusted. The image below shows a trendline pointing at an 0.31°C adjustment for a 1900 baseline. 

Additional adjustment is needed when using a 1750 baseline, while it also makes sense to add further adjustment for higher polar anomalies and for air temperatures over oceans, rather than sea surface water temperatures. In total, a 0.78°C adjustment seems appropriate, as has been applied before, such as in this analysis. For the year 2020, this translates in a temperature rise of 1.8029°C versus the year 1750.

Three trends: blue, purple and red

Will the global temperature rise to 3°C above 1750 by 2026? The blue trend below is based on 1880-2020 NASA Land+Ocean data and adjusted by 0.78°C to reflect a 1750 baseline, ocean air temperatures and higher polar anomalies, and it crosses a 3°C rise in 2026.

The trend shows a temperature for 2020 that is slightly higher than indicated by the data. This is in line with the fact that we're currently in a La Niña period and that we're also at a low point in the sunspot cycle, as discussed in an earlier post. The blue trend also shows that the 1.5°C treshold was already crossed even before the Paris Agreement was accepted. 

The second (purple) trend is based on a shorter period, i.e. 2006-2020 NASA land+ocean (LOTI) data, again adjusted by 0.78°C to reflect a 1750 baseline, ocean air temperatures and higher polar anomalies. The trend approaches 10°C above 1750 by 2026. The trend is based on 15 years of data, making it span a 30-year period centered around end 2020 when extended into the future for a similar 15 year period. The trend approaches 10°C above 1750 in 2026.

The trend is displayed on the backdrop of an image from an earlier post, showing how a 10°C rise could eventuate by 2026 when adding up the impact of warming elements and their interaction.

The stacked bars are somewhat higher than the trend. Keep in mind that the stacked bars are for the month February, when anomalies can be significantly higher than the annual average.

Temperature rise for February 2016 versus 1900.
In the NASA image on the right, the February 2016 temperature was 1.70°C above 1900 (i.e. 1885-1914). In the stacked-bar analysis, the February 2016 rise from 1900 was conservately given a value of 1.62°C, which was extended into the future, while an additional 0.3°C was added for temperature rise from pre-industrial to 1900.

Later analyses such as this one also added a further 0.2°C to the temperature rise, to reflect ocean air temperatures (rather than water temperatures) and higher polar anomalies (note the grey areas on the image in the right).

Anyway, the image shows two types of analysis on top of each other, one analysis based on trend analysis and another analysis based on a midel using high values for the various warming elements. The stacked-bar analysis actually doesn't reflect the worst-case scenario, an even faster rise is illustrated by the next trend, the red line.

The third (red) trend suggests that we may have crossed the 2°C treshold in the year 2020. The trend is based on a recent period (2009-2020) of the NASA land+ocean data, again adjusted by 0.78°C to reflect a 1750 baseline, ocean air temperatures and higher polar anomalies.

Where do we go from here? 

It's important to acknowledge the danger of acceleration of the temperature rise over the next few years. The threat is illustrated by the image below and shows upmost prominently in the red trend. 

Of the three trends, the red trend is based on the shortest period, and it does indicate that we have aready crossed the 2°C treshold and we could be facing an even steeper temperature rise over the next few years.

We're in a La Niña period and we're also at a low point in the sunspot cycle. This suppresses the temperature somewhat, so the 2020 temperature should actually be adjusted upward to compensate for such variables. Importantly, while such variables do show up more when basing trends on shorter periods, the data have not be adjusted for this in this case, so the situation could actually be even worse. 

At a 3°C rise, humans will likely go extinct, while most life on Earth will disappear with a 5°C rise, and as the temperature keeps rising, oceans will evaporate and Earth will go the same way as Venus, a 2019 analysis warned. 

Dangerous acceleration of the temperature rise 

There are many potential causes behind the acceleration of the temperature rise, such as the fact that the strongest impact of carbon dioxide is felt ten years after emission, so we are yet to experience the full wrath of the carbon dioxide emitted over the past decade. However, this doesn't explain why 2020 turned out to be the hottest year on record, as opposed to - say - 2019, given that in 2020 carbon dioxide emissions were 7% lower than in 2019.

James Hansen confirms that the temperature rise is accelerating, and he points at aerosols as the cause. However, most cooling aerosols come from industries such as smelters and coal-fired power plants that have hardly reduced their operations in 2020, as illustrated by the image below, from the aerosols page

Above image shows that on December 17, 2020, at 10:00 UTC, sulfate aerosols (SO₄) were as high as 6.396 τ at the green circle. Wind on the image is measured at 850 hPa.

Could the land sink be decreasing? A recent study shows that the mean temperature of the warmest quarter (3-month period) passed the thermal maximum for photosynthesis during the past decade. At higher temperatures, respiration rates continue to rise in contrast to sharply declining rates of photosynthesis. Under business-as-usual emissions, this divergence elicits a near halving of the land sink strength by as early as 2040. While this is a frightening prospect, it still doesn't explain why 2020 turned out to be the hottest year on record. 

Oceans are taking up less heat, thus leaving more heat in the atmosphere. The danger is illustrated by the image below. 

The white band around -60° (South) indicates that the Southern Ocean has not yet caught up with global warming, featuring low-level clouds that reflect sunlight back into space. Over time, the low clouds will decrease, which will allow more sunlight to be absorbed by Earth and give the world additional warming. A recent study finds that, after this 'pattern effect' is accounted for, committed global warming at present-day forcing rises by 0.7°C. While this is very worrying, it still doesn't explain why 2020 turned out to be the hottest year on record. 

Ocean stratification contributes to further surface warming, concludes another recent study
"The stronger ocean warming within upper layers versus deep water has caused an increase of ocean stratification in the past half century. With increased stratification, heat from climate warming less effectively penetrates into the deep ocean, which contributes to further surface warming. It also reduces the capability of the ocean to store carbon, exacerbating global surface warming. Furthermore, climate warming prevents the vertical exchanges of nutrients and oxygen, thus impacting the food supply of whole marine ecosystems."
"By uptaking ~90% of anthropogenic heat and ~30% of the carbon emissions, the ocean buffers global warming. [The] ocean has already absorbed an immense amount of heat, and will continue to absorb excess energy in the Earth’s system until atmospheric carbon levels are significantly lowered. In other words, the excess heat already in the ocean, and heat likely to enter the ocean in the coming years, will continue to affect weather patterns, sea level, and ocean biota for some time, even under zero carbon emission conditions."
Many feedbacks are starting to kick in with greater ferocity, with tipping points threatening to get crossed or already crossed, such as the latent heat tipping point, i.e. loss of the ocean heat buffer, as Arctic sea ice keeps getting thinner. As the above map also shows, the temperature rise is hitting the Arctic Ocean particularly hard. At least ten tipping points are affecting the Arctic, including the latent heat tipping point and the methane hydrates tipping point, as illustrated by the image below.
[ from an earlier post ]

A combination of higher temperatures and the resulting feedbacks such as stronger ocean stratification, stronger wind, decline of Arctic snow and ice and a distorted Jet Stream is threatening to cause formation of a lid at the surface of the North Atlantic Ocean that enables more heat to move to the Arctic Ocean. This could cause huge amounts of methane to erupt from the seafloor, thus contributing to cause the 1,200 ppm CO₂e cloud tipping point to get crossed, resulting in an extra 8°C rise, as an earlier post and a recent post warned.

Dangerous acceleration of the temperature rise

The danger is that methane is erupting in the Arctic from the seafloor and that this increasingly contributes to methane reaching the stratosphere. 

While methane initially is very potent in heating up the atmosphere, it is generally broken down relatively quickly, but in the atmosphere over the Arctic, there is very little hydroxyl to break down the methane. 

Methane also persists much longer in the stratosphere, which contributes to its accumulation there. 

Large amounts of methane may already be erupting from the seafloor of the Arctic Ocean, rising rapidly and even reaching the stratosphere

This danger is getting little public attention. The NOAA image on the right shows the globally-averaged, monthly mean atmospheric methane abundance derived from measurements from marine surface sites. Measurements that are taken at sea level do not reflect methane very well that is rising up from the seafloor of the Arctic Ocean, especially where the methane rises up high in plumes. 

Satellite measurements better reflect the danger. The image on the right shows that the MetOp-1 satellite recorded peak methane levels as high as 2715 ppb at 469 mb on the morning of January 6, 2021. 

Most of the high (magenta-colored) levels of methane are located over oceans and a lot of them over the Arctic Ocean. 

The next image on the right shows the situation closer to sea level, at 586 mb, where even less of the high levels of methane show up over land, indicating that the methane originated from the seafloor. 

The third image on the righ shows the situation even closer to sea level, at 742 mb, and almost all high levels of methane show up over the Arctic Ocean and over areas where the Atlantic Ocean and the Pacific Ocean border on the Arctic. 

Because methane is lighter than air and much lighter than water, methane erupting from the seafloor will quickly rise up vertically. While much of the methane that is released from the seabed can get broken down in the water by microbes, methane that is rising rapidly and highly concentrated in the form of plumes will leave little opportunity for microbes to break it down in the water column, especially where waters are shallow,
as is the case in much of the Arctic Ocean.

As methane hydrates destabilize, methane will erupt with an explosive force, since methane is highly compressed inside the hydrate (1 m³ of methane hydrate can release 160 m³ of gas). Such eruptions can destabilize further hydrates located nearby. Because of this explosive force, plumes of methane can rise at high speed through the water column. 

Because methane is so much lighter than water, large methane releases from the seafloor will form larger bubbles that merge and stick together, developing more thrust as they rise through the water.

Because of this thrust, methane plumes will keep rising rapidly after entering the atmosphere, and the plumes will more easily push away aerosols and gases that slow down the rise in the air of methane elsewhere, such as where methane is emitted by cows. 

A further image of another satellite is added on the right. The N2O satellite recorded methane levels as high as 2817 ppb at 487 mb on the morning of January 10, 2021. 

Such sudden and very high peaks can hardly be caused by agriculture or wetlands, but instead they are likely caused by destabilization of methane hydrates in sediments at the seafloor. 

Further contributing to the danger is the fact that little hydroxyl is present in the atmosphere over the Arctic, so it is much harder for this methane to get broken down in the air over the Arctic, compared to methane emissions elsewhere. 

Finally, the edge of the stratosphere is much lower over the Arctic, as discussed in an earlier post.

All this makes that methane that is erupting from the seafloor of the Arctic Ocean is more prone to accumulate in the stratosphere. Once methane is in the stratosphere, it's unlikely that it will come back into the troposphere.

The IPCC AR5 (2013) gave methane a lifetime of 12.4 years. The IPCC TAR (2001) gave stratospheric methane a lifetime of 120 years, adding that less than 7% of methane did reach the stratosphere at the time. According to IPCC AR5, of the methane that gets broken down by hydroxyl in the atmosphere, some 8.5% got broken down in the stratosphere.


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

In the video below, Paul Beckwith discusses the situation: 

For another perspective, Guy McPherson discusses the situation in the video below, Edge of Extinction: Maybe I’m Wrong


• Climate Plan

• NASA Global Land-Ocean Temperature Index

• What are El Niño and La Niña?

• Multivariate El Niño/Southern Oscillation (ENSO) Index Version 2 (MEI.v2) 
• Temperatures keep rising

• There is no time to lose

• Possible climate transitions from breakup of stratocumulus decks under greenhouse warming, by Tapio Schneider et al. (2019)

• A rise of 18°C or 32.4°F by 2026?

• Greater committed warming after accounting for the pattern effect - by Chen Zhou et al. 

• Upper Ocean Temperatures Hit Record High in 2020 - by Lijing Cheng et al.

• How close are we to the temperature tipping point of the terrestrial biosphere? - by Katharyn Duffy et al.

• Methane hydrates tipping point threatens to get crossed

• Cold freshwater lid on North Atlantic

• Aerosols

• NOAA - Trends in Atmospheric Methane

•  COVID-19 lockdown causes unprecedented drop in global CO2 emissions in 2020 - Gobal Carbon Project

• Global Average Temperatures in 2020 Reached a RECORD HIGH of 1.55 C above PreIndustrial in 1750 - by Paul Beckwith

• Edge of Extinction: Maybe I’m Wrong - by Guy McPherson

• Extinction

Saturday, April 18, 2015

The Great Unraveling

The great unraveling of how climate catastrophe is unfolding on land and in the oceans, in the atmosphere and the cryosphere, is becoming more and more clear every month.

March 2015 temperatures were the highest for March in the 136-year period of record. NOAA analysis shows that the average temperature across global land and ocean surface temperatures combined for March 2015 was 0.85°C (1.53°F) higher than the 20th century average of 12.7°C (54.9°F).

Ocean temperature anomalies on the Northern Hemisphere for March 2015 were the highest on record. In many ways, the situation looks set to get worse. For the 12-month period from April to March, data from 1880 contain a trendline that points at a rise of 2 degrees Celsius by the year 2032, as illustrated by the image below.

Click on image to enlarge
The rise in Northern Hemisphere ocean temperatures was especially profound in September and October 2014, when methane started to erupt from the Arctic Ocean seafloor in huge quantities.

The image below shows a polynomial trendline pointing at an October Northern Hemisphere sea surface temperature anomaly rise of 2°C (3.6°F) by 2030, and a rise of more than 5°C (9°F) by 2050, compared to the 20th century average, from an earlier post.
From: Ocean Temperature Rise continues
The images below give an idea of the current sea surface temperature anomalies around North America.

On April 11, 2015, a sea surface temperature of 22.2°C (71.96°F) was recorded off the North
American coast (green circle bottom), a 12.6°C (22.68°F) anomaly (green circle top).

Ocean heat is carried by the Gulf Stream from the North Atlantic into the Arctic Ocean. The huge amounts of energy entering the oceans translate into higher temperatures of the water and of the air over the water, as well as higher waves and stronger winds.

The image below highlights waves and winds, showing that waves as high as 12.06 m (39.57 ft) were recorded off the coast of North America in the path of the Gulf Stream, while winds with speeds as high as 115 km/h (71.46 mph) were recorded in that area on April 17, 2015.

The combination image below illustrates the threat. A sea surface temperature of 8°C (46.4°F, green circle left) was recorded near Svalbard on April 17, 2015, an anomaly of 6.2°C (11.16°F, green circle right).

Click on image to enlarge
A continued rise of ocean temperatures on the Northern Hemisphere threatens to unleash huge eruptions of methane from the seafloor of the Arctic Ocean, further accelerating the temperature rise in the Arctic and escalating into runaway global warming.

Malcolm Light comments: "The Pacific heating must be caused by the southward spreading Arctic methane global warming veil that is able to penetrate through a giant hole in the hydroxyl and ozone layer over the far east and is moving eastwards."

Current methane levels remain extremely high (see this recent post), on track to break the record mean level of 1839 ppb (parts per billion) reached in September 2014.

Above image shows that the highest mean methane levels ranged from 1815 ppb on March 30, 2015, to 1828 ppb on April 17, 2015. The highest peak level during this period was 2483 ppb, reached on April 15, 2015.

The extremely high methane levels are undoubtedly contributing to the high temperatures reached in March, especially at higher latitudes, on top of the dramatic global rise of greenhouse gases in general, as illustrated by above contribution by Peter Carter.

Above image shows that temperature anomalies over much of the Arctic Ocean were at the top end of the scale on April 17, 2015, i.e. 20°C or 36°F.

The image below gives an idea of the temperature differences on April 17, 215. While temperatures over the Sahara in Africa were as high as 32.1°C (89.78°F), temperatures over Greenland were as low as -41°C (-41.8°F). In between, temperatures of 2.8°C (37.04°) were recorded over the waters near Svalbard and of 6.1°C (42.98°F) closer to the coast of Norway.

Such wide temperature differences highlight the importance of looking at peaks, rather than at averages. The year-to-date maximum sea surface temperature anomaly, up to April 18, 2015, gives an idea of the peak anomalies that can be expected as the hot season approaches on the Northern Hemisphere.

Below are details for March 2015.

Temperature anomalies as high as 10.2°C (or 18.3°F) were recorded for March 2015 on Kolguyev Island in the Barents Sea.

A rise in ocean temperatures on the Northern Hemisphere of 2°C (3.6°F) by October 2030 looks set to go hand in hand with a 6°C (10.8°F) rise in Arctic temperatures by 2030, fueling runaway global warming, as illustrated by the image below, from another earlier post.

Without action, similar temperature rises look set to hit the globe at large a dozen years later, accompanied by huge temperature swings that threaten to cause depletion of supply of food and fresh water, as discussed by Guy McPherson in the video below and illustrated by the image further below.

Guy McPherson (left) in discussion with Paul Beckwith (right)

From Methane Levels Early 2015

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

Sources and Related

- Ocean temperatures, NOAA

- Sea Surface Temperatures, from:
and from:

- Kolguyev Island temperature anomaly, from:

- Temperature anomaly April 17, 2015, Climate Reanalyzer

- Year-to-date maximum sea surface temperature anomaly April 18, 2015, from:

- Methane levels. NOAA IASI MetOp

- The Mechanism

- Three kinds of warming (temperature trendlines), from: Methane levels Early 2015

- Northern Hemisphere October Ocean Temperature Rise, from:

Ocean temperature anomalies on the Northern Hemisphere for March 2015 were the highest on record. In many ways, the...
Posted by Sam Carana on Saturday, April 18, 2015