Arctic News: change

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Saturday, February 3, 2018

Is warming in the Arctic behind this year's crazy winter weather?

Is warming in the Arctic behind this year's crazy winter weather?

File 20180111 101511 sa3hd1.jpg?ixlib=rb 1.1 — Seriously cold: The ‘bomb cyclone’ freezes a fountain in New York City.
AP Photo/Mark Lennihan

Jennifer Francis, Rutgers University

Damage from extreme weather events during 2017 racked up the biggest-ever bills for the U.S. Most of these events involved conditions that align intuitively with global warming: heat records, drought, wildfires, coastal flooding, hurricane damage and heavy rainfall.

Paradoxical, though, are possible ties between climate change and the recent spate of frigid weeks in eastern North America. A very new and “hot topic” in climate change research is the notion that rapid warming and wholesale melting of the Arctic may be playing a role in causing persistent cold spells.

It doesn’t take a stretch of the imagination to suppose that losing half the Arctic sea-ice cover in only 30 years might be wreaking havoc with the weather, but exactly how is not yet clear. As a research atmospheric scientist, I study how warming in the Arctic is affecting temperature regions around the world. Can we say changes to the Arctic driven by global warming have had a role in the freakish winter weather North America has experienced?

A ‘dipole’ of abnormal temperatures

Weird and destructive weather was in the news almost constantly during 2017, and 2018 seems to be following the same script. Most U.S. Easterners shivered their way through the end of 2017 into the New Year, while Westerners longed for rain to dampen parched soils and extinguish wildfires. Blizzards have plagued the Eastern Seaboard – notably the “bomb cyclone” storm on Jan. 4, 2018 – while California’s Sierra Nevada stand nearly bare of snow.

A study in contrasts: Warming near Alaska and the Pacific Ocean are ‘ingredients’ to a weather pattern where cold air from the Arctic plunges deep into North America.
NASA Earth Observatory, CC BY

This story is becoming a familiar one, as similar conditions have played out in four of the past five winters. Some politicians in Washington D.C., including President Trump, have used the unusual cold to question global warming. But if they looked at the big picture, they’d see that eastern cold spells are a relative fluke in the Northern Hemisphere as a whole and that most areas are warmer than normal.

A warm, dry western North America occurring in combination with a cold, snowy east is not unusual, but the prevalence and persistence of this pattern in recent years have piqued the interests of climate researchers.

The jet stream – a fast, upper-level river of wind that encircles the Northern Hemisphere – plays a critical role. When the jet stream swoops far north and south in a big wave, extreme conditions can result. During the past few weeks, a big swing northward, forming what’s called a “ridge” of persistent atmospheric pressure, persisted off the West Coast along with a deep southward dip, or a “trough,” over the East.

New terms have been coined to describe these stubborn features: “The North American Winter Temperature Dipole,” the “Ridiculously Resilient Ridge” over the West, and the “Terribly Tenacious Trough” in the East.

While the eastern U.S. suffered very cold temperatures in the recent cold snap, much of the rest of the Northern Hemisphere saw higher-than-average air temperatures.
NOAA, CC BY

Regardless what it’s called, this dipole pattern – abnormally high temperatures over much of the West along with chilly conditions in the East – has dominated North American weather in four of the past five winters. January 2017 was a stark exception, when a strong El Niño flipped the ridge-trough pattern, dumping record-breaking rain and snowpack on California while the east enjoyed a mild month.

Two other important features are conspicuous in the dipole temperature pattern: extremely warm temperatures in the Arctic near Alaska and warm ocean temperatures in the eastern Pacific. Several new studies point to these “ingredients” as key to the recent years with a persistent dipole.

It takes two to tango

What role does warming – specifically the warming ocean and air temperatures in the Arctic – play in this warm-West/cool-East weather pattern? The explanation goes like this.

Pacific Ocean temperatures fluctuate naturally owing to short-lived phenomena such as El Niño/La Niña and longer, decades-length patterns. Scientists have long recognized that those variations affect weather patterns across North America and beyond.

When a persistent area of atmospheric pressure stays in the western U.S., air from the Arctic pours into the U.S, causing a split between the warm and dry West and the cold East.
Mesocyclone2014 and David Swain, CC BY-SA

The new twist in this story is that the Arctic has been warming at at least double the pace of the rest of the globe, meaning that the difference in temperature between the Arctic and areas farther south has been shrinking. This matters because the north/south temperature difference is one of the main drivers of the jet stream. The jet stream creates the high- and low-pressure systems that dictate our blue skies and storminess while also steering them. Anything that affects the jet stream will also affect our weather.

When ocean temperatures off the West Coast of North America are warmer than normal, as they have been most of the time since winter 2013, the jet stream tends to form a ridge of high pressure along the West Coast, causing storms to be diverted away from California and leaving much of the West high and dry.

If these warm ocean temperatures occur in combination with abnormally warm conditions near Alaska, the extra heat from the Arctic can intensify the ridge, causing it to reach farther northward, become more persistent, and pump even more heat into the region near Alaska. And in recent years, Alaska has experienced periods of record warm temperatures, owing in part to reduced sea ice.

My colleagues and I have called this combination of natural and climate change-related effects “It Takes Two to Tango,” a concept that may help explain the Ridiculously Resilient Ridge observed frequently since 2013. Several new studies support this human-caused boost of a natural pattern, though controversy still exists regarding the mechanisms linking rapid Arctic warming with weather patterns farther south in the mid-latitudes.

More extreme weather ahead?

In response to the strengthened western ridge of atmospheric pressure, the winds of the jet stream usually also form a deeper, stronger trough downstream. Deep troughs act like an open refrigerator door, allowing frigid Arctic air to plunge southward, bringing misery to areas ill-prepared to handle it. Snowstorms in Texas, ice storms in Georgia and chilly snowbirds in Florida can all be blamed on the Terribly Tenacious Trough of December 2017 and January 2018.

Cold weather from the Arctic combined with warm tropical air fueled a storm that produced well over a foot of snow and spots of flooding in Boston.
AP Photo/Michael Dwyer

Adding icing on the cake is the tendency for so-called “nor’easters,” such as the “bomb cyclone” that struck on Jan. 4, to form along the East Coast when the trough’s southwest winds align along the Atlantic Seaboard. The resulting intense contrast in temperature between the cold land and Gulf Stream-warmed ocean provides the fuel for these ferocious storms.

The big question is whether climate change will make dipole patterns – along with their attendant tendencies to produce extreme weather – more common in the future. The answer is yes and no.

It is widely expected that global warming will produce fewer low-temperature records, a tendency already observed. But it may also be true that cold spells will become more persistent as dipole patterns intensify, a tendency that also seems to be occurring.

It’s hard to nail down whether this weather pattern – overall warmer winters in North America but longer cold snaps – will persist. Understanding the mechanisms behind these complex interactions between natural influences and human-caused changes is challenging.

Nevertheless, research is moving forward rapidly as creative new metrics are developed. Our best tools for looking into the future are sophisticated computer programs, but they, too, struggle to simulate these complicated behaviors of the climate system. Given the importance of predicting extreme weather and its impacts on many aspects of our lives, researchers must continue to unravel connections between climate change and weather to help us prepare for the likely ongoing tantrums by Mother Nature.

Jennifer Francis, Research Professor, Rutgers University

This article was originally published on The Conversation. Read the original article.

Thursday, February 1, 2018

North Pole forecast to be above freezing on Feb 5, 2018

The image below shows a forecast of above freezing temperatures over the North Pole on Feb 5, 2018.

Above image shows a forecast of air temperature of 0.2°C or 32.4°F at 1000 hPa over the North Pole on February 5, 2018, 21:00 UTC.

Above image shows a forecast of temperatures of 1.1 °C or 33.9°F at the North Pole at 1000 hPa, on February 5, 2018, 18:00 UTC.

Above image shows a large area around the North Pole forecast to be up to 30°C or 54°F warmer than 1979-2000 on February 5, 2018.

Above image shows sea surface temperatures as high as 15.1°C or 59.2°F near Svalbard on February 9, 2018, in the panel on the left, and air temperatures as high as 6°C or 42.7°F (at 1000 hPa) near Svalbard on February 10, 2018, in the panel on the right.

These high temperatures are caused not only by ocean heat, but also by strong winds pushing warm air and water up from the North Atlantic into the Arctic. Above image shows the Jet Stream moving at speeds as high as 315 km/h or 196 mph (green circle, February 6, 2018, 6:00 UTC), moving in backward direction over Scandinavia, while extending over Antarctica and crossing the Equator at a number of places.

The decreasing temperature difference between the North Pole and the Equator is slowing down the speed at which the jet stream circumnavigates Earth and this is also making the jet stream more wavy.

As a more wavy jet stream extends deeper down over land, it allows cold air from the Arctic to flow down over land. As temperatures over land fall, the difference between ocean temperature and land temperature increases, especially in winter when land temperatures are much lower than ocean temperatures. This increasing difference between land and ocean temperature makes winds stronger and faster over oceans.

[ click on images to enlarge ]

In above image, the left panel shows a wavy jet stream speeding up over the North Atlantic, reaching speeds as high as 345 km/h or 215 mph (at green circle, 250 hPa).

In above image, the right panel shows strong winds pushing warm air from the Pacific Ocean through Bering Strait, resulting in temperatures over Alaska as high as 6.6°C or 44°F (at green circle, at 850 hPa).

The image on the right shows that waves as high as 8.27 m or 27.2 ft (at green circle) are forecast to enter the Arctic Ocean near Svalbard on February 5, 2018, giving an indication of the huge amount of energy that is going into oceans.

Earth is retaining more heat. This translates into higher surface temperatures, more heat getting stored in oceans and stronger winds. This in turn is causing higher waves and more evaporation from the sea surface. The image on the right shows a forecast of total amount of cloud water (in air from surface to space) of 1.5 kg/m² (green circle) in between Svalbard and the North Pole on February 5, 2018.

Warm air, warm water and high waves make it hard for sea ice to form, while evaporation from the ocean adds more water vapor to the atmosphere. Since water vapor is a potent greenhouse gas, this further accelerates warming of the Arctic.

The high temperatures at the North Pole follow high temperatures over East Siberia, as illustrated by the image below.

Above image shows average temperature anomalies for January 31, 2018, compared to 1979-2000. The image below shows open water on the East Siberian coast in the Arctic Ocean that day.

Meanwhile, Arctic sea ice extent is very low. The image below shows that extent on January 30, 2018, was 13.391 million km², a record low for the time of the year.

In the video below, Paul Beckwith discusses the situation.

In the podcast below, by Wolfgang Werminghausen, entitled Sam Carana about the Arctic and global temperature, Sam Carana's responses are read by Kevin Hester.

From the interview, Sam Carana: "Methane releases from the seafloor of the Arctic Ocean have a strong warming impact, especially locally, AND methane releases in the Arctic also act as a catalyst for other feedbacks that are all self-reinforcing and interlinked, amplifying each other in many ways. It could easily become 10°C or 18°F warmer in a matter of years, especially in places where most people are now living."

The image below shows that on February 11, 2018, methane reached peak levels as high as 2925 ppb.

High methane peaks are becoming more common as the water temperature of oceans keeps rising, which also goes hand in hand with more water vapor and less sea ice. As said, these are all warming elements that amplify each other in many ways.

On Feb 8, 2018, Antarctic sea ice extent was 2.382 million km², a record low for the time of the year and 1.811 million km² less than the extent on Feb 8, 2014.

The image on the right illustrates the huge loss of sea ice around Antarctica over the past few years. Antarctic sea ice looks set to reach an all-time low extent later this month, with a difference of close to 2 million km² persisting, compared to just a few years ago.

The image below shows a forecast for February 5, 2018, with as much as 3.84 kg/m² (green circle) Total Cloud Water in between South Africa and Antarctica.

More water vapor in the air contributes to global warming, since water vapor is a potent greenhouse gas. The image below shows a forecast for February 5, 2018, with temperatures on Antarctica reaching as high as 8.9°C or 47.9°F (update Feb. 11, 2018: 7.1°C or 44.7°F at 78°S, 17°E at 1000 hPa on Feb. 5, 2018, 15:00z).

At this time of year, global sea ice is typically at its lowest extent for the year. On February 9, 2018, global sea ice reached the lowest extent on record, as illustrated by the image below by Wipneus.

This means that a huge amount of sunlight that was previously reflected back into space is now instead getting absorbed by oceans.

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

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.

Tuesday, January 2, 2018

Unfolding Arctic Catastrophe

On January 1, 2018, methane levels as high as 2764 ppb (parts per billion) were recorded. The solid magenta-colored areas near Greenland indicate that this very high reading was likely caused by methane hydrate destabilization in the sediments on the seafloor of the Arctic Ocean.

The state of the sea ice is behind this. On January 1, 2018, Arctic sea ice extent was at record low for the time of the year. The smaller the extent, the less sunlight gets reflected back into space and is instead absorbed in the Arctic.

At this time of year, though, hardly any sunshine is reaching the Arctic. So, what triggered this destabilization? As the image below indicates, year-to-date average Arctic sea ice volume has been at record low in 2017, which means that there has been very little sea ice underneath the surface throughout 2017.

Warm water will melt the sea ice from below, which keeps the water at greater depth cool. However, when there is little or no sea ice underneath the surface, little or no heat will be absorbed by the process of melting and the heat instead stays in the water, with the danger that it will reach sediments at the bottom of the Arctic Ocean, as illustrated by the image below.

The Buffer has gone, feedback #14 on the Feedbacks page

[ image from: Warming is accelerating ]

The image on the right shows warm water from the North Atlantic arriving near Svalbard. How warm is the water beneath the surface of the Arctic Ocean? The image below gives an indication, showing how much warmer the water was from October 1, 2017, to December 30, 2017, at selected areas near Svalbard, where warm water from the North Atlantic dives under the sea ice of the Arctic Ocean, carried by the Gulf Stream.

[ click on images to enlarge ]

In 1981-2011, temperatures were gradually falling by more than one degree Celsius from October 1 to the December 21 Solstice, then started to rise again in line with the change in seasons (blue line). In 2017, temperatures were rising in October. On October 25, 2017, the sea surface was as warm as 17.5°C or 63.5°F, i.e. a 14.1°C or 24.5°F anomaly. On average, it was 12.96°C or 23.35°F warmer during the period from October 1 to December 30, 2017 (red line), compared to the same days in 1981-2011.

The images below further illustrate the situation. Surface temperature of the atmosphere near Svalbard was as warm as 7°C or 44.5°F on January 13, 2018 (at green circle, left panel). The sea surface near Svalbard was as warm as 15.9°C or 60.8°F on January 12, 2018, compared to 2.4°C or 36.4°F on January 12 for the period 1981-2011 (at green circle, center panel). Waves as high as 13.04 m or 42.8 ft (at green circle, right panel) batter the North Atlantic along Norway's coast all the way to Svalbard on January 15, 2018.

The image below shows that waves as high as 16.01 m or 52.5 ft are forecast to batter the North Atlantic on January 16, 2018 (green circle, left panel). 100% relative humidity is recorded over the Arctic Ocean on January 15, 2018 (green circle, center panel). The Jet Stream reaches speeds as high as 426 km/h or 264 mph on January 15, 2018 (green circle, right panel).

Similar extreme weather patterns can be seen elsewhere in the Arctic. The image below on the left shows that temperatures as high as 18.5°C or 65.3°F were recorded on Jan. 14 and 15, 2018 in Metlakatla, Alaska. The image below on the right shows that surface temperatures as high as 7.4°C or 45.2°F were reached on January 16, 2018, in Yukon Territory, Canada (at green circle).

[ click on images to enlarge ]

Saturday, May 13, 2017

Abrupt Warming - How Much And How Fast?

How much could temperatures rise? As the image shows, a rise of more than 10°C (18°F) could take place, resulting in mass extinction of many species, including humans.

How fast could such a temperature rise eventuate? As above image also shows, such a rise could take place within a few years. The polynomial trend is based on NASA January 2012-February 2017 anomalies from 1951-1980, adjusted by +0.59°C to cater for the rise from 1750 to 1951-1980. The trend points at a 3°C rise in the course of 2018, which would be devastating. Moreover, the rise doesn't stop there and the trend points at a 10°C rise as early as the year 2021.

Is this polynomial trend the most appropriate one? This has been discussed for years, e.g. at the Controversy Page, and more recently at Which Trend Is best?

The bottom part of above image shows the warming elements that add up to the 10°C (18°F) temperature rise. Figures for five elements may be overestimated (as indicated by the ⇦ symbol) or underestimated (⇨ symbol), while figures in two elements could be either under- or overestimated depending on developments in other elements. Interaction between warming elements is included, i.e. where applicable, figures on the image include interaction based on initial figures and subsequently apportioned over the relevant elements.

A closer look at each of these warming elements further explains why abrupt warming could take place in a matter of years. As far as the first two elements are concerned, i.e. the rise from 1900 and the rise from 1750 to 1900, this has already eventuated. The speed at which further warming elements can strike is depicted in the image below, i.e. the rise could for a large part occur within years and in some cases within days and even immediately.

Assessing the Danger

The danger can be looked at on three dimensions: timescale, probability and severity. On the severity dimension, a 10°C temperature rise is beyond catastrophic, i.e. we're talking about extinction of species at massive scale, including humans. On the probability dimension, the danger appears to be progressing inevitably toward certainty if no comprehensive and effective action is taken.

In terms of timescale, a 10°C temperature rise could eventuate within a matter of years, which makes the danger imminent, adding further weight to the need to start taking comprehensive and effective action, as described in the Climate Plan.

The Threat

With little or no action taken on global warming, it appears that the Antropocene will lead to extinction of the very human beings after which the era is named, with the Anthropocene possibly running from 1950 to 2021, i.e. a mere 71 years and much too short to constitute an era. In that case a better name for the period would be the Sixth Extiction Event, as also illustrated by the image below.

[ See: Feedbacks in the Arctic and the Extinction page ]

In conclusion, it's high time that homo sapiens starts acting as genuinely wise modern human beings and commit to comprehensive and effective action as discussed at the Climate Plan.

Further reading

Read more about the threat here. Warming elements are discussed in more detail at the Extinction Page, while specific elements are also discussed in posts, e.g. methane hydrates are discussed at Methane Erupting From Arctic Ocean, decline of the snow and ice cover and associated feedbacks is discussed at Arctic Ocean Feedbacks and less take-up by oceans of CO₂ and heat from the atmosphere is discussed at 10°C or 18°F warmer by 2021? and at the new post High Waves Set To Batter Arctic Ocean.

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

Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

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

• The Threat
https://arctic-news.blogspot.com/p/threat.html

• Controversy
https://arctic-news.blogspot.com/p/controversy.html

• Which Trend Is best?
https://arctic-news.blogspot.com/2017/03/which-trend-is-best.html

• 10°C or 18°F warmer by 2021?
https://arctic-news.blogspot.com/2017/04/10c-or-18f-warmer-by-2021.html

• Arctic Ocean Feedbacks
https://arctic-news.blogspot.com/2017/01/arctic-ocean-feedbacks.html

• Methane Erupting From Arctic Ocean
https://arctic-news.blogspot.com/2017/03/methane-erupting-from-arctic-ocean-seafloor.html

• High Waves Set To Batter Arctic Ocean
https://arctic-news.blogspot.com/2017/06/high-waves-set-to-batter-arctic-ocean.html

• Warning of mass extinction of species, including humans, within one decade
https://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html

Saturday, February 25, 2017

Accelerating growth in CO₂ levels in the atmosphere

CO₂ Growth

In 2016, CO₂ levels in the atmosphere grew by 3.36 ppm (parts per million), a new record since 1959 and much higher than the previous record set in 2015.

Worryingly, above graph has a trendline added pointing at a growth rate in CO₂ levels of 6 ppm per year by 2026.

Growth in levels of CO₂ in the atmosphere is accelerating, despite reports that - for the third year in a row - carbon dioxide emissions from fossil fuels and industry (including cement production) had barely grown, as illustrated by the Global Carbon Project image below.

Why is growth in CO₂ levels in the atmosphere accelerating?

So, what makes growth in CO₂ levels in the atmosphere accelerate? As discussed in a previous post, growth in CO₂ levels in the atmosphere is accelerating due to:

Deforestation and Soil Degradation:
Agricultural practices such as depleting groundwater and aquifers, plowing, mono-cultures and cutting and burning of trees to raise livestock can significantly reduce the carbon content of soils, along with soil moisture and nutrients levels.
Climate change and extreme weather events:
The recent jump in global temperature appears to have severely damaged soils and vegetation. Soil carbon loss and enhanced decomposition of vegetation appear to have occurred both because of the temperature rise and the resulting extreme weather events such as heatwaves, drought, dust-storms and wildfires, and storms, hail, lightning, flooding and the associated erosion, turning parts of what was once a huge land sink into sources of CO₂ emissions.
Moreover, extreme weather events can also lead to emissions other than CO₂ emissions, such as soot, nitrous oxide, methane and carbon monoxide, which can in turn cause a rise in the levels of ground-level ozone, thus further weakening vegetation and making plants even more vulnerable to pests and infestations.
Oceans may also be taking up less CO₂ than before:
Oceans have absorbed some 40% of CO₂ emissions since the start of the industrial era. Up until recently, oceans still took up some 26% of carbon dioxide emitted by people annually. As discussed earlier, oceans are getting warmer, and warm water holds less oxygen than cold water. Furthermore, as the water warms, it tends to form a layer at the surface that does not mix well with cooler, nutrient-rich water below, depriving phytoplankton of some of the nutrients needed in order for phytoplankton to grow. Less phytoplankton in the oceans means that oceans become less able to take up carbon dioxide from the atmosphere. A study by Boyce et al. found a decrease of about 1% per year of phytoplankton in oceans globally. Sergei Petrovskii, co-author of a 2015 study, found that a rise in the water temperature of the world’s oceans of about 6°C could stop oxygen production by phytoplankton by disrupting the process of photosynthesis, adding that “About two-thirds of the planet’s total atmospheric oxygen is produced by ocean phytoplankton – and therefore cessation would result in the depletion of atmospheric oxygen on a global scale. This would likely result in the mass mortality of animals and humans.”

Biomass

Sensitivity

Meanwhile, research including a 2014 study by Franks et al. concludes that the IPCC was too low in its estimates for the upcoming temperature rise locked in for current CO₂ levels. A study by Friedrich et al. updates IPCC estimates for sensitivity to CO₂ rise, concluding that temperatures could rise by as much as 7.36°C by 2100 as a result of rising CO₂ levels.

When also taking further elements than CO₂ more fully into account, we could face an even larger temperature rise, i.e. a rise of 10°C (or 18°F) by 2026 (compared to pre-industrial), as further described at the extinction page that specifies the different elements of such a rise, including a 0.5°C rise due to CO₂ emissions from 2016 to 2026. The CO₂ growth discussed in this post appears to be in line with such a rise and in line with the associated loss of carbon sinks and rising vulnerability of carbon pools.

The situation looks particularly threatening in the Arctic where many of the most vulnerable carbon pools are located, where temperatures are rising fastest and where CO₂ levels have recently risen rapidly (see image below with CO₂ readings at Barrow, Alaska).