Arctic News: heat

Showing posts with label heat. Show all posts

Tuesday, April 17, 2018

Heat Storm

[ click on images to enlarge ]

On April 11, 2018, Arctic sea ice extent was only 13.9 million km². Arctic sea ice extent has been at a record low for the time of year for most of 2018, as illustrated by above image. In 2012, extent went below 3.4 million km². The question is what minimum 2018 extent will be.

Arctic sea ice could disappear altogether in 2018. Have a look at the progressive loss of sea ice volume depicted in the image on the right, from an earlier post. Zero sea ice volume by 2018 is within the margins of the trend line contained in the data going back to 1979.

What drives volume decline is the combination of extent loss and especially thickness loss. Sea ice thickness has declined particularly where the ice once was at its thickest, i.e. north of Greenland and the Canadian Arctic Archipelago.

The combination image below shows the decline of the thicker sea ice, by comparing sea ice thickness on April 15 (run April 14) for the years 2015 through to 2018, showing that sea ice this year is entering the melting season with little or no thick sea ice left north of Greenland and the Canadian Arctic Archipelago to cope with the influx of warmer water.

The image below shows how much Bering Strait sea ice is at a historic low and the associated International Arctic Research Center post describes that this is caused by higher ocean temperatures and frequent storms.

The influx of warm water from the Atlantic Ocean and from the Pacific Ocean is melting the sea ice from below, while sunlight is melting the sea ice from above. Furthermore, warm water from rivers that end in the Arctic Ocean also contribute to melting of the sea ice, and there are numerous feedbacks that can dramatically speed up melting.

Disappearance of the sea ice means that the buffer that until now has consumed huge amounts of heat, will be gone and that heat that previously went into melting the sea ice, will instead warm up the Arctic.

Sea ice can be expected to continue its downward spiral, given the continued rise of the temperature of the sea surface in the North Atlantic Ocean and the North Pacific Ocean, as illustrated by the image below.

The sea surface is not necessarily the place where the water is at its warmest. This is illustrated by the image below, showing subsurface ocean heat in the area most relevant to El Niño/La Niña events.

[ click on images to enlarge ]

We're currently still in a La Niña period in which temperatures are suppressed, as illustrated by the Multivariate El Niño/Southern Oscillation (ENSO) Index image on the right.

As illustrated by the forecast plumes image underneath on the right, it looks like a new El Niño will arrive this summer, which will elevate temperatures from the trend.

This could result in a heat storm as early as summer 2018, in which heat waves could decimate the sea ice, while storms could push the remaining sea ice out of the Arctic Ocean.

This danger is further illustrated by the trend line in the image below, a trend that is contained in NASA LOTI data up to March 2018, adjusted by +0.79°C to better reflect the rise from preindustrial and surface air temperatures, and to better include Arctic temperatures.

[ click on images to enlarge ]

The temperature rise in the Arctic is causing decline of the sea ice extent as well as the extent of the snow cover on land.

The image on the right shows the progressive decline of the spring snow cover on land in the Northern Hemisphere.

A recent study shows that the amount of water melt from the glaciers on Mt. Hunter, Alaska, is now 60 times greater than it was before 1850.

Heat waves combined with strong rainfall due to storms could devastate the snow cover in 2018.

Decline of the snow and ice cover in the Arctic comes with a huge loss in albedo, which means that huge amounts of sunlight that were previously reflected back into space instead get absorbed by the Arctic.

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A rapid rise in temperatures in the Arctic will also accelerate changes to jet stream, which can cause huge amounts of heat from the Atlantic Ocean and the Pacific Ocean to enter the Arctic Ocean, further speeding up its warming and threatening to destabilize methane hydrates in sediments under the Arctic Ocean.

The methane will initially be felt most strongly in the Arctic, further speeding up Arctic warming which is already accelerating due to numerous feedbacks including - as said - the loss of the snow and ice cover in the Arctic, which makes that less sunlight is reflected back into space and instead adds to warming up the Arctic.

All this shouldn't come unexpected. In the video below, Guy McPherson warns that a rapid temperature rise will affect agriculture across the globe, threatening to cause a collapse of industrial civilization, in turn resulting in an abrupt halt of the sulfates that are currently co-emitted as a result of burning fuel, which will further add to a temperature rise that is already threatening to cause people across the globe to perish at massive scale, due to heatstroke, dehydration and famine, if not perish due to nuclear radiation and further toxic effects of war, as people fight over who controls the last habitable places on Earth.

Guy mentions the President of Finland, Sauli Niinistö, who in a press conference on August 28, 2017, warns that: "If we lose the Arctic, we lose the globe". The video below shows an extract of the press conference.

Monday, January 22, 2018

2017 was hottest year on record

The year 2017 was the hottest year on record, as the image below illustrates.

When determining which year was the hottest year, care should be taken to avoid bias due to temporary conditions such as the El Niño that was present in 2016 and the La Niña we're now experiencing now. Above image uses NASA land+ocean January 2012-December 2017 anomalies from 1951-1980, adjusted by 0.59°C to cater for the rise from preindustrial to 1951-1980, to calculate a linear trend that goes some way to smooth out variability due to El Niño/La Niña events. The trend shows that 2017 was significantly warmer than 2016.

The trend also shows that 1.5°C above preindustrial was crossed back in 2016. This 1.5°C (or 2.7°F) was set at the Paris Agreement as a guardrail that was not to be crossed. The trend further shows that we've meanwhile crossed 1.6°C above preindustrial and we look set to cross the 2°C guardrail within years.

Global warming has crossed 1.5°C / 2.7°F above preindustrial and looks set to cross 2°C / 3.6°F soon. Due to accelerating warming in the Arctic, that could happen within one or two years time, i.e. much faster than the trendlines below may suggest.

Indeed, warming in the Arctic is taking place much faster than elsewhere, and the difference is accelerating. There's a huge danger that accelerating warming in the Arctic will speed up feedbacks such as:
• huge amounts of methane getting released from the seafloor of the Arctic Ocean;
• melting of sea ice and permafrost causing more sunlight to get absorbed in the Arctic, as less sunlight gets reflected back into space;
• changes to jet streams causing more extreme weather, in turn resulting in more emissions, such as due to wildfires;
• and more.

In conclusion, feedbacks could speed up global warming by much more than what may be suggested by above trends that look only at surface temperature of the atmosphere and that are based on previous data when such feedbacks had yet to become manifest.

Add up the impact of all warming elements and, as an earlier analysis shows, the rise in mean global temperatures from preindustrial could be more than 10°C in a matter of years, as illustrated by the image below, which shows a much steeper rise.

Particularly devastating feedbacks could result from changes regarding heat and carbon dioxide taken up by oceans. Oceans now take up 93.4% of global warming, as illustrated by the image below.

As said, when looking at surface temperatures of the atmosphere, there will be bias due to El Niño/La Niña events. One way to smooth out such bias is by calculating trendlines over many years. Another way to compensate for such bias is to also look at ocean heat. In terms of ocean heat, the year 2017 stands at the top, as the left panel of above image illustrates. In 2016, El Niño caused relatively more heat to be present in the atmosphere and less in oceans, whereas the opposite occurred in 2017, contributing to the fact that in 2017 a record amount of ocean heat was recorded. Occurrence of El Niño/La Niña events over the years is visualized by the image below.

One danger is that, in future, there will be more impact by El Niño events and less by La Niña events. A recent study concludes that as temperatures rise due to emissions by people, the frequency, magnitude and duration of strong El Niño events will increase.

In addition to higher temperature peaks due to El Niño events, more heat could remain in the atmosphere as the rise in temperature in general causes greater ocean stratification, making that less heat gets absorbed by oceans, as discussed in several earlier posts. The image below depicts this feedback and further feedbacks mentioned above. Feedbacks are described in more detail at the feedbacks page.

The situation is further illustrated by the danger assessment below.

[ Danger Assessment, from earlier post ]

Meanwhile, the Global Carbon Project projects a growth of 2% for the 2017 global carbon dioxide emissions from fossil fuels and industry (including cement production), compared to 2016 levels, as illustrated by image below.

Friday, November 24, 2017

Warming is accelerating

Warming is accelerating. For some time, it has been warmer than the 1.5°C guardrail that the Paris Agreement promised should not be crossed. This conclusion follows from above analysis of NASA land+ocean data 1880-October 2017, adjusted by 0.59°C to cater for the rise from preindustrial and with a trend added that also indicates that the global temperature look set to cross the 2°C guardrail soon, with 2021 falling within the margins of the trend line.

[ click on images to enlarge ]

The trend line shows a strong and ominous direction upward. Nonetheless, the situation could be even more dire than this trend indicates, since some warming elements are not fully incorporated in these data.

As an example, the NASA data look at the temperature at the surface of the oceans, which has increased strongly, as also illustrated by the image on the right.

Much warming has also occurred below the sea surface, while there has been some cooling of the sea surface. Moreover, ocean heat has also increased strongly over the years, as the image below illustrates, and looks set to increase further.

After all, what happens to oceans is important, as 93.4% of global warming currently goes into oceans.

The fact that much warming is taking place below the sea surface could make that it gets overlooked. If much of this warming were to get transferred from the Arctic Ocean to the atmosphere over the next few years, then the temperature rise over the next few years could take an even sharper turn upward.

The threat that warming below the sea surface is overlooked is highlighted by the image below, which shows huge warming of Arctic waters at selected locations near Svalbard.

Above image focuses on temperatures at selected locations near Svalbard (see map below). In 1981-2011, temperatures were gradually falling by more than one degree Celsius over the period of measurement, i.e. from October 1 to November 23 (blue line), a fall that is in line with the change in seasons. Over this period in 2017, temperatures were 13.19°C or 23.77°F higher than in 1981-2011, while the temperature didn't seem to be falling (red line).

How could these waters get a stunning 13.19°C warmer than two decades ago?

Global warming did hit the North Atlantic hard, particularly along the track of the Gulf Stream all the way to the Arctic Ocean. This has translated into stronger winds along the track of the Gulf Stream, which are making that ever larger amounts of warm water are getting pushed from the North Atlantic to the Arctic Ocean.

A temperature rise underneath the sea surface can be overlooked when merely monitoring the average surface temperature of the Arctic Ocean, especially when stronger winds have caused more evaporation, cooling down the water at the surface.

[ 100% relative humidity (left) as jet stream moves over Arctic Ocean (right) ]

Stronger winds, higher temperatures and the presence of more open water in the Arctic have all contributed to stronger rainfall in the Arctic. It looks like the rain did cause a freshwater lid to form at the surface of the Arctic Ocean, acting as an insulator and preventing transfer of ocean heat to the atmosphere. This also contributed to a colder atmosphere over the Arctic Ocean, i.e. colder than it would otherwise have been. At the same time, since less heat could escape from the Arctic Ocean to the atmosphere, this freshwater lid has resulted in warmer water, as is evident from the huge anomalies at the locations near Svalbard. The forecast below that Arctic will be 7.2°C or 12.96°F warmer than in 1979-2000 on December 3, 2017, illustrates just how warm the Arctic Ocean currently is.

This freshwater lid has also made it easier for sea ice to form at the surface, as ice will form in freshwater as warm as just below 0°C (or 32°F), compared to salty seawater that must cool down to -2°C (or 28.4°F) before freezing. The seawater underneath the sea ice is warm enough to melt the ice from below, but the layer of freshwater at the surface acts as an insulator.

There would have been less sea ice, had it not been for the rain resulting in this freshwater lid. Much of the freshwater lid did turn into sea ice in September 2017, as air temperatures came down below 0°Cs, and this sea ice similarly acted as an insulator, preventing transfer of heat from the Arctic Ocean to the atmosphere. Importantly, while much of the additional freshwater at the surface did turn into sea ice in 2017, this is only a temporary phenomenon, as no ice will form once the surface of the water will stay above 0°C, which looks imminent as temperatures keep rising.

[ Cyclone carrying particulates into the Arctic Ocean ]

Further sea ice loss means that less sunlight will get reflected back into space and will instead get absorbed by the Arctic, further accelerating warming in the arctic.

Additionally, more heat is radiated from sea ice into space than from open water (feedback #23).

Stronger cyclones can also bring more particulates into the Arctic Ocean, speeding up the demise of sea ice by darkening it when settling on ice, as illustrated by the image on the right.

In conclusion, while the formation of the freshwater lid at the surface of the Arctic Ocean has been holding back the collapse of the sea ice, the delay of the collapse can only be a temporary one as temperatures keep rising. The Arctic Ocean is warming at accelerating speed and collapse of the sea ice looks imminent.

[ click on image to enlarge ]

Above images confirm the loss of the thicker sea ice over the past few years, while zero Arctic sea ice is within the margins of the trend line of the image on the right.

Less sea ice will on the one hand make that more heat can escape from the Arctic Ocean to the atmosphere, but on the other hand the albedo loss and the additional water vapor will at the same time cause the Arctic Ocean to absorb more heat, with the likely net effect being greater warming of the Arctic Ocean.

Another point to consider is latent heat, as discussed in earlier posts. The danger is illustrated by the image below, showing that heat threatens to destabilize methane hydrates at the seafloor of the Arctic Ocean. As the temperature of the Arctic Ocean keeps rising, more heat threatens to reach sediments that have until now remained frozen. Melting of the ice in these sediments then threatens to unleash huge eruptions of seafloor methane that has until now been kept locked up by the permafrost.

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Additionally, melting of permafrost on land can cause rapid decomposition of soils, resulting in releases of huge amounts of greenhouse gases, further accelerating warming in the Arctic, which in turn will result in more greenhouse gases (CO2, CH4, N2O, water vapor) entering the Arctic atmosphere, more albedo changes, etc., in a vicious self-reinforcing cycle of runaway warming.

Levels of CO2, CH4 an N2O have been rising rapidly since 1750, as above image shows. Methane levels have risen 257% since 1750.

Did the rise in methane emissions slow down from 1999 to 2006?

One explanation for the apparent slowdown is that, as temperatures kept rising, water vapor in the atmosphere increased accordingly (7% more water vapor for every 1°C warming), resulting in more hydroxyl that broke down more methane in the atmosphere since 1990. So, while the rise in methane levels appeared to slow down, methane emissions were actually continuing to increase, but as an increasingly large part of methane was decomposed by hydroxyl, this rise in methane was overlooked. In 2007, Arctic sea ice reached a record low, triggering more methane eruptions from the seafloor of the Arctic Ocean. While hydroxyl kept increasing, seafloor methane kept increasing faster, making that methane emissions increasingly started to overwhelm hydroxyl, resulting in a stronger rise in overall methane levels. In 2013, I estimated methane emissions at 771 Tg/y, whereas the IPCC's estimate was 678 Tg/y. The post estimated methane from hydrates and permafrost at 13% of total methane emissions, whereas the IPCC's estimate was a mere 1% of total methane emissions. - Sam Carana, Dec. 2017.

[ click on images to enlarge ]

The presence of methane is felt particularly strongly over the Arctic Ocean. Above images show high methane levels over the Arctic Ocean on December 2, 2017, when methane reached a peak level of 2771 ppb and on December 13 and 14, 2017, when peak levels as high as 2713 ppb were reached.

Methane levels have been rising strongly since 2000 and this rise looks set to continue, as illustrated by the image on the right.

There is also a danger that, as temperatures keep rising, the course of the ocean current near Svalbard could change, making that more heat will reach the East Siberian Arctic Shelf (ESAS), thus further warming up sediments there, resulting in huge amounts of methane erupting from the seafloor.

Add up the impact of all warming elements and, as an earlier analysis shows, the rise in mean global temperatures from preindustrial could be more than 10°C in a matter of years, as illustrated by the images below.

A 2°C rise in temperature alone is devastating, especially when considering that temperature peaks in history look to have been less high than previously thought, as concluded by a recent study in ocean paleotemperature. Therefore, a 10°C rise may well result in the warmest temperatures experienced on Earth. Moreover, the speed at which this rise could occur leaves little or no time for plants and animals to adapt, in contrast to historical climate swings that typically took many years to eventuate.

Thursday, April 13, 2017

The Methane Threat

Carbon dioxide levels in the atmosphere are accelerating. As illustrated by the image below, a linear trend hardly catches the acceleration, while a polynomial trend does make a better fit. The polynomial trend points at CO₂ levels of 437 ppm by 2026.

EPA animation: more extreme heat

This worrying acceleration is taking place while energy-related have been virtually flat over the past few years, according to figures by the EIA and by the Global Carbon Project. So, what makes growth in CO₂ levels in the atmosphere accelerate? As earlier discussed in this and this post, growth in CO₂ levels in the atmosphere is accelerating due to continued deforestation and soil degradation, due to ever more extreme weather events and due to accelerating warming that is making oceans unable to further take up carbon dioxide.

Ocean warming is accelerating on the Northern Hemisphere, as illustrated by above image, and a warmer Atlantic Ocean will push ever warmer water into the Arctic Ocean, further speeding up the decline of the sea ice and of permafrost.

[ click on images to enlarge ]

Loss of Northern Hemisphere snow cover is alarming, especially in July, as depicted in above image. The panel on the left shows snow cover on the Northern Hemisphere in three areas, i.e. Greenland, North America and Eurasia. The center panel shows North America and the right panel shows Eurasia. While Greenland is losing huge amounts of ice from melting glaciers, a lot of snow cover still remains present on Greenland, unlike the permafrost in North America and especially Eurasia, which has all but disappeared in July.

[ for original image, see 2011 AGU poster ]

Worryingly, the linear trend in the right panel points at zero snow cover in 2017, which should act as a warning that climate change could strike a lot faster than many may expect.

A recently-published study warns that permafrost loss is likely to be 4 million km² (about 1.5 million mi²) for each 1°C (1.8°F) temperature rise, about 20% higher than previous studies. Temperatures may well rise even faster, due to numerous self-reinforcing feedback loops that speed up the changes and due to interaction between the individual warming elements behind the changes.

[ Arctic sea ice, gone by Sept. 2017? ]

One of the feedbacks is albedo loss that speeds up warming in the Arctic, in turn making permafrost release greenhouse gases such as carbon dioxide, nitrous oxide and methane.

Higher temperatures on land will make warmer water from rivers enter the Arctic Ocean and trigger wildfires resulting in huge emissions including black carbon that can settle on sea ice.

Given the speed at which many feedbacks and the interaction between warming elements can occur, Arctic sea ice volume may decline even more rapidly than the image on the right may suggest.

[ Record sea ice volume anomalies since end 2016 ]

Ominously, sea ice volume anomalies have been at record levels for time of year since end 2016 (Wipneus graph right, PIOMAS data).

As the Gulf Stream pushes warmer water into the Arctic Ocean, there will no longer be a large buffer of sea ice there to consume the heat, as was common for the entire human history.

Moreover, forecasts are that temperatures will keep rising throughout 2017 and beyond.

The Australian Bureau of Meteorology reports that seven of eight models indicate that sea surface temperatures will exceed El Niño thresholds during the second half of 2017.

The image on the right, by the ECMWF (European Centre for Medium-Range Weather Forecasts), indicates an El Niño that is gaining strength.

For more than half a year now, global sea ice extent has been way below what it used to be, meaning that a huge amount of sunlight that was previously reflected back into space, is now instead getting absorbed by Earth, as the graph below shows.

[ Graph by Wipneus ]

Where can all this extra heat go? Sea ice will start sealing off much of the surface of the Arctic Ocean by the end of September 2017, making it hard for more heat to escape from the Arctic Ocean by entering the atmosphere.

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It looks like much of the extra heat will instead reach sediments at the seafloor of the Arctic Ocean that contain huge amounts of methane in currently still frozen hydrates.

[ click on image to enlarge ]

The danger is that more and more heat will reach the seafloor and will destabilize methane hydrates contained in sediments at the bottom of the Arctic Ocean, resulting in huge methane eruptions.

As the image on the right shows, a polynomial trend based on NOAA July 1983 to January 2017 global monthly mean methane data, points at twice as much methane by 2034. Stronger methane releases from the seafloor could make such a doubling occur much earlier.

Meanwhile, methane levels as high as 2592 ppb were recorded on April 17, 2017, as shown by the image below. The image doesn't specify the source of the high reading, but the magenta-colored area over the East Siberian Sea (top right) looks very threatening.

We already are in the Sixth Mass Extinction Event, given the rate at which species are currently disappearing from Earth. When taking into account the many elements that are contributing to warming, a potential warming of 10°C (18°F) could take place, leading to a rapid mass extinction of many species, including humans.