Showing posts with label extreme weather. Show all posts
Showing posts with label extreme weather. Show all posts

Saturday, October 11, 2014

Climate Change Accelerating

Methane levels as high as 2562 ppb were recorded on October 9, 2014, as illustrated by the image below.

Many grey areas show up in the image where QC (quality control) failed, as it was too hard to read methane levels in the respective area, apparently due to high moisture levels (i.e. snow, rain or water vapor) in the atmosphere.


As above image illustrates, cloud cover is high over the Arctic, while there is also precipatation in the form of snowfall.

In other words, high levels of methane (above 1950 ppb, colored yellow) could be present over a much larger part of the Arctic Ocean, while methane in these grey areas could be even higher than the measured peak level of 2456 ppb.

This appears to be confirmed by persistent high methane levels over vast areas across the Arctic Ocean both in the morning (top part of the image further above) and in the afternoon (bottom part of image) on 9 October 2014.

Methane levels are this high over the Arctic Ocean for the number of reasons, including:
  • The Gulf Stream keeps pushing warm water into the Arctic Ocean.
  • The resulting eruptions of methane from the seafloor of the Arctic Ocean constitute a feedback that accelerates warming in the Arctic. 
  • As the Arctic warms up more rapidly than the rest of Earth, the Arctic's ice and snow cover will decline, further accelerating warming in the Arctic.
  • As the Arctic warms up more rapidly than the rest of Earth, the speed at which jet streams circumnavigates the Northern Hemisphere will weaken, making it meander more, resulting in a greater frequency and intensity of extreme weather events, such as heat waves, droughts and wildfires. 
Here's an example of intense warming. Look at what is currently happening on Greenland.

As the image above right shows, sea surface temperature anomalies as high as +1.89°C hit the North Atlantic (on October 8, 2014). 

Furthermore, high cloud cover over the Arctic (image further above) makes it hard for the heat there to radiate out into space, further contributing to high temperature anomalies.

The image on the right shows high temperature anomalies over Greenland and parts of the Arctic Ocean on October 11, 2014. Note that anomalies are averaged out over the course of the day (and night).

The image below (right) shows anomalies at the top end of the scale hitting large parts of Greenland at a specific time during this day. The left part of the image below shows how this could happen, i.e. jet streams curling around Greenland trapping warm air inflow from the North Atlantic.


As said, as the Arctic warms up more rapidly than the rest of Earth, the speed at which jet streams circumnavigate the Northern Hemisphere will weaken, making the jets meander more and creating patterns that can trap heat (or cold) for a number of days over a given area. Due to the height of its mountains, Greenland is particularly prone to be increasingly hit by heatwaves resulting from such blocking patterns. Warming changes the texture of snow and ice, making it more slushy and darker, which also makes that it absorbs more of the sunlight's heat, further accelerating melting.

As Paul Beckwith warns in an earlier post, melt rates on Greenland have doubled in the last 4 to 5 years, and melt rates on the Antarctica Peninsula have increased even faster. Based on the last several decades, melt rates have had a doubling period of around 7 years or so. If this trend continues, we can expect a sea level rise approaching 7 meters by 2070.

From: More than 2.5 m sea level rise by 2040
These are all indications that the pace of climate change is accelerating in many ways, the most dangerous one being ever larger methane eruptions from the Arctic Ocean's seafloor. As the image below shows, sea surface temperature anomalies are very high in the Arctic Ocean, indicating very high temperatures under the surface.



U.S. Secretary of State John Kerry recently said: “There are now – right now – serious food shortages taking place in places like Central America because regions are battling the worst droughts in decades, not 100-year events in terms of floods, in terms of fires, in terms of droughts – 500-year events, something unheard of in our measurement of weather.” Warning about looming catastrophe, Kerry adds: “Life as you know it on Earth ends. Seven degrees increase Fahrenheit (3.9°C), and we can't sustain crops, water, life under those circumstances.”

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




Monday, June 16, 2014

Warming of the Arctic Fueling Extreme Weather

Extreme weather

Heavy rains and floods hit Serbia and Bosnia in May 2014, as discussed in an earlier post.

Later in May, further flooding hit central Europe. From May 30 to June 1, 2014, parts of Austria received the amount of rain that normally falls in two-and-half months: 150 to 200 mm (5.9 to 7.9"), with some parts experiencing 250 mm (9.8").

What is fueling this extreme weather? Have a look at the image below.



The image shows a number of feedbacks that are accelerating warming in the Arctic. Feedback #14 refers to (latent) heat that previously went into melting. With the demise of the snow and ice cover, an increasing proportion of this heat gets absorbed and contributes to accelerated warming in the Arctic.

As the sea ice heats up, 2.06 J/g of heat goes into every degree Celsius that the temperature of the ice rises. While the ice is melting, all energy (at 334J/g) goes into changing ice into water and the temperature remains at 0°C (273.15K, 32°F). 

Once all ice has turned into water, all subsequent heat goes into heating up the water, at 4.18 J/g for every degree Celsius that the temperature of water rises.

The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C. The energy required to melt a volume of ice can raise the temperature of the same volume of rock by 150º C.

Currently, the energy equivalent of 1.5 million Hiroshima bombs goes into melting of the Arctic sea ice each year, according to calculations by Sam Carana.

As the ice disappears, this energy will instead be absorbed elsewhere and cause temperatures in the Arctic to rise further, indicated as feedback #14.

This comes on top of the albedo feedback #1 that can on its own more than double the net radiative forcing resulting from the emissions caused by all people of the world, according to calculations by Prof. Peter Wadhams.

Further feedbacks include changes to the polar vortex and jet stream that are in turn causing more extreme weather, as also described in the earlier post Feedbacks in the Arctic.


Global Warming

Higher levels of greenhouse gases are trapping more heat in the atmosphere, resulting in more intense heatwaves in some places, while stronger winds and greater evaporation of water from the sea lead to stronger rainfall in other places. Global warming thus contributes to more extreme weather around the globe.

The Arctic is hit not only by the warming resulting from greenhouse gas emissions, but also by emissions of soot, dust and other compounds that settle on the snow and ice cover and speed up its demise.

As illustrated by the image below, by Nuccitelli et al., most heat goes into the oceans. A substantial amount of heat also goes into the melting of ice.

A lot of ocean heat is transported by the Gulf Stream into the Arctic Ocean. The North Atlantic is hit particularly strongly by pollution from North America, as illustrated by the image below.

[ screenshot from Perdue University's Vulcan animation ]
Heat carried by the Gulf Stream into the Arctic Ocean contributes to high sea surface anomalies in the Arctic, as illustrated by the image below. Arctic sea ice is under threat from heat from the North Atlantic, while heat from the Pacific Ocean that was in part caused by pollution from east-Asia is now threatening to enter the Arctic Ocean through the Bering Strait, as illustrated by the image below that shows areas with sea surface temperature anomalies well over 8 degrees Celsius. 

[ click on image to enlarge ]
Warmer water in the Arctic Ocean in turn causes methane to be released from the seafloor of the Arctic Ocean, as discussed further below. 


Accelerated Warming in the Arctic

As said, warming hits the Arctic particularly strongly due to feedbacks such as albedo changes caused by the demise of the snow and ice cover in the Arctic. Another feedback is a changing jet stream. The jet stream used to circumnavigate the globe at high speed, separating climate systems that used to be vastly different above and below the jet stream. Accelerated warming in the Arctic is decreasing the temperature difference between the Arctic and the Equator, in turn causing the jet stream to slow down and become wavier. As a result, air can more easily move north to south and visa versa, especially when the jet stream's waves expand vertically and take a long time to move from west to east (i.e. a blocking pattern).

These changes to the jet stream are fueling extreme weather events. In the May/June event, a large loop had developed in the jet stream over Europe and got stuck in place, making a strong southerly wind carry moisture-laden air from the Mediterranean Sea over Central Europe, clashing with colder air flowing down from the north as the jet stream was stuck in such a blocking pattern.

Record May heat hit northern Finland and surrounding regions of Russia and Sweden. Earlier in May (on May 19) an all-time national heat record was set of 91.4°F (33.0°C) in St. Petersburg, Russia, slashing the previous record by a wide margin. This temperature was unprecedented in records in St. Petersburg that started in 1881 and show a previous May record set in 1958 of 87.6°F (30.9°C).

The compilation below shows the jet stream on three days (May 24, 25 and 27), on top of surface temperature anomalies for those days.

[ click on image to enlarge ]

Further illustrating the event is the animation below, showing the jet stream from May 26 to June 11, 2014. Note that this is a 14.5 MB file that may take some time to fully load.

[ click on image to enlarge ]
Methane

Huge methane emissions took place from the seafloor of the Arctic Ocean from September 2013 to March 2014. These emissions have meanwhile risen up higher in the atmosphere and have moved closer to the equator.


Compared to June 2013, mean methane levels at higher altitudes are now well over 10 ppb higher at higher altitudes while there has been only little change closer to the ground. Since these mean levels are global means, the difference is even more pronounced at specific locations on the Northern hemisphere, where clouds of methane originating from the Arctic are contributing to the occurence of heat waves.

The contribution of methane to such heatwaves depends on the density of the methane at the time in the atmosphere over the location during such events.

Highest global mean methane levels varied from 1907 ppb to 1812 ppb for the period June 6 to 15, 2014, as illustrated by the image on the right, and peak methane concentration varied a lot from day to day. On June 6, 2014, peak readings as high as 2516 ppb were recorded.

Indicative for what can be the result is the temperature anomaly on May 19, when temperatures went up as high as 91.4°F (33.0°C) in St. Petersburg, Russia, slashing the previous record by a wide margin, of more than 2°C, as described above


Conclusion

The situation is the Arctic is threatening to escalate into runaway warming and urgently requires comprehensive and effective action as discussed at the Climate Plan blog.


References

- May 2014 Global Weather Extremes Summary

- Extreme Jet Stream Pattern Triggers Historic European Floods
http://www.wunderground.com/blog/JeffMasters/extreme-jet-stream-pattern-triggers-historic-european-floods


Related posts

- The Biggest Story of 2013
http://arctic-news.blogspot.com/2013/12/the-biggest-story-of-2013.html

- Climate Plan
http://climateplan.blogspot.com
- More extreme weather can be expected
http://arctic-news.blogspot.com/2014/05/more-extreme-weather-can-be-expected.html

- Extreme weather strikes around the globe - update
http://arctic-news.blogspot.com/2014/02/extreme-weather-strikes-around-the-globe-update.html

- Escalating extreme weather events to hammer humanity (by Paul Beckwith)
http://arctic-news.blogspot.com/2014/04/escalating-extreme-weather-events-to-hammer-humanity.html

- Our New Climate and Weather (by Paul Beckwith)
http://arctic-news.blogspot.com/2014/01/our-new-climate-and-weather.html

- Our New Climate and Weather - part 2 (by Paul Beckwith)
http://arctic-news.blogspot.com/2014/01/our-new-climate-and-weather-part-2.html

- Changes to Polar Vortex affect mile-deep ocean circulation patterns
http://arctic-news.blogspot.com/2012/09/changes-to-polar-vortex-affect-mile-deep-ocean-circulation-patterns.html

- Polar jet stream appears hugely deformed
http://arctic-news.blogspot.com/2012/12/polar-jet-stream-appears-hugely-deformed.html




Saturday, April 5, 2014

Escalating extreme weather events to hammer humanity


By Paul Beckwith

Extreme weather events are rocketing upwards in their frequency of occurrence, intensity, and duration and are impacting new regions that are unprepared. These events, such as torrential rains, are causing floods and damaging crops and infrastructure like roads, rail, pipelines, and buildings. Cities, states, and entire countries are being battered and inundated resulting in disruption to many peoples lives as well as enormous economic losses. As bad as this is, it is going to get much worse by at least 10 to 20 times. Why?

Greenhouse gas emissions from humans have changed the chemistry of the atmosphere. The optical absorption of infrared heat has increased in the atmosphere which raises temperature, and thus water vapor content, and therefore fuels more intense storms. The jet streams that guide these storms are slower and wavier and more fractured and cause our weather gyrations and weird behavior. Areas far north can get very warm, while areas far south can get very cold. Some areas get persistent drought. Then, the pattern can flip. The jet streams are much wavier in the north-south direction since the Arctic temperatures have warmed 5 to 8 times faster than the global average. This reduces the temperature difference between the Arctic and equator and basic physics forces the jets to slow and get wavier.

Why is the Arctic warming greatly amplified? The region is darkening and thus absorbing more sunlight, since the land-based snow cover in spring and the Arctic sea ice cover volume are both declining exponentially. The white snow and ice is being replaced by dark surfaces like the ocean and the tundra. The most detailed computer model on sea ice decline is a U.S. Naval Graduate School model, and it shows the sea ice cover could be gone by late summer in 2016. If this happens, the Arctic warming will rocket upwards, the jets will distort much more, and the extreme weather events will rocket upwards in frequency, amplitude, and duration and civilization will be hammered.


Paul Beckwith
Paul Beckwith is part-time professor with the laboratory for paleoclimatology and climatology, department of geography, University of Ottawa. Paul teaches climatology/meteorology and does PhD research on 'Abrupt climate change in the past and present'. Paul holds an M.Sc. in laser physics and a B.Eng. in engineering physics and reached the rank of chess master in a previous life. Below are Paul's earlier posts at the Arctic-news blog.


Paul Beckwith with sign (arrows highlighted by 
Sam Carana, from earlier post)

Below, a recent video in which Paul Beckwith discusses how a weaker Jet Stream lets warmer air move from lower latitudes into the Arctic (feedback #10).


From December, 2013 until early April, 2014 there have been persistent and very large temperature anomalies in the northern hemisphere (+20 C = +36 F in the Arctic, -20 C = -36 F in vast parts of the US and Canada). I claim that this represents a previously unrecognized large positive feedback acting to homogenize the temperature in the northern hemisphere.



Earlier posts by Paul Beckwith

- Abrupt Climate Change

- Our New Climate and Weather - part 2

- Our New Climate and Weather

- Are Alberta’s Tar Sands prepared for a torrential rain event?

- Stop All New Fossil Fuel Megaprojects

- Toward Genuinely Improved Discussions of Methane & Climate

- The Social Tipping Point

- Arctic Cyclone July 2013

- Arctic Ocean Events - Videos by Paul Beckwith

- Climate change fighting town savaged by runaway oil train

- Extreme weather becomes the norm - what can you do?

- Thin Spots developing in Arctic Sea Ice

- The Tornado Connection to Climate Change

- Anthropogenic Arctic Volcano can calm climate

- Hold on folks… the times they are a-changin’

- Hurricane Sandy moving inland

- Open Letter to Canadian MPs

- State of Climate Change October 2012

- Is death by lead worse than death by climate? No.

- You are now entering the nonlinearity zone…

- Vanishing Arctic sea ice is rapidly changing global climate

- Storm enters Arctic region

- Update on September Arctic cyclone

- Arctic cyclone warning for September 7

- Paul Beckwith on ice speed and drift - update 1

- Paul Beckwith on ice speed and drift

- Another Arctic Cyclone brewing

- Sea ice in the Arctic - Shaken and stirred (by a powerful cyclone)

- How to part ways with a climate denier that has incredible stamina...



Thursday, October 24, 2013

Are Alberta’s Tar Sands prepared for a torrential rain event?

by Paul Beckwith

In recent months we have endured incredible tropical-equatorial-like torrential rain events occurring at mid-latitudes across the planet. For example, in North America we experienced intense rainfall in the Banff region of the Rockies from June 19th to 24th and the enormous volume of water moved downhill through the river systems taking out small towns and running into the heart of Calgary where it caused $5.3 billion dollars of infrastructure damage; the largest in Canadian history.

Next, it was Toronto’s turn, with 75 mm of rain falling from 5 to 6pm on July 8 (with up to 150 mm overall in some regions) leading to widespread flooding and $1.45 billion dollars in damages. As bad as these events were, they were dwarfed by the intense rainfalls hitting the state of Colorado from Sept 9th to 15th.

Rainfall amounts that would normally fall over 6 months to a year were experienced in less than a week. Widespread flash floods, landslides, and torrents of water ripped apart roads, fracking equipment and pipelines on (at least) hundreds of fossil fuel sites (mostly ignored by mainstream media) (http://www.desmogblog.com/2013/09/19/media-ignores-damaged-oil-and-gas-tanks-colorado-floods). The level of destruction was simply horrifying, as captured by a man with a plane and a camera. But we have no grounds for complaint, since the widespread flooding in central Europe from May 30th to June 6th caused a much larger $22 billion in damages.

So what is happening? Why are we experiencing so many of these severe weather flooding events that are supposed to only occur every 1000 years or so? Will they keep occurring? What city will be hit next? Can the Alberta tar sands be hit by such an event? What would be the implications?

Abrupt Climate Change In Real-Time

Humans have benefited greatly from a stable climate for the last 11,000 years - roughly 400 generations. Not anymore. We now face an angry climate. One that we have poked in the eye with our fossil fuel stick and awakened. Now we must deal with the consequences. We must set aside our differences and prepare for what we can no longer avoid. And that is massive disruption to our civilizations.

In a nutshell, the logical chain of events occurring is as follows:
  1. Greenhouse gases that humans are putting into the atmosphere from burning fossil fuels are trappingextra heat in the earth system (distributed between the oceans (93%), the cryosphere (glaciers, ice sheets, sea ice for 3%), the earth surface (rocks, vegetation, etc. for 3%) and the atmosphere (only an amazingly low 1%). The oceans clearly get the lions share of the energy, and if that 1% heating the atmosphere varies there can be decades of higher or lower warming, as we have seen recently. This water vapor rises and cools condensing into clouds and releasing its stored latent heat which is increasing storm intensity.
  2. (i)Rapidly declining Arctic sea ice (losing about 12% of volume per decade) and (ii)snow cover (losing about 22% of coverage in June per decade) and (iii)darkening of Greenland all cause more solar absorption on the surface and thus amplified Arctic warming (global temperatures have increased (on average) about 0.17oC per decade, the Arctic has increased > 1oC per decade, or about 6x faster)
  3. Equator-to-Arctic temperature difference is thus decreasing rapidly
  4. Less heat transfer occurs from equator to pole (via atmosphere, and thus jet streams become streakier and wavier and slower in west-to-east direction, and via ocean currents (like Gulf Stream, which slows and overruns continental shelf on Eastern seaboard of U.S.)
  5. Storms (guided by jet streams) are slower and sticking and with more water content are dumping huge torrential rain quantities on cities and widespread regions at higher latitudes than is “normal”.
  6. A relatively rare meteorological event called an “atmospheric river” is now much more common, and injects huge quantities of water over several days to specific regions, such as Banff (with water running downhill to Calgary) and Toronto and Colorado events.
It is well past the time that politicians and governments need to act to address these issues. This breakdown of the global atmospheric circulation pattern is well underway now, with a global average temperature only 0.8oC above the pre-industrial revolution levels. With extreme weather events this terrible now, it is highly irrational, in fact reckless, to continue to have global meetings and discussions about whether or not 2oC is safe. Only 0.8oC is wreaking havoc on global infrastructure today. As climate change proceeds and accelerates and we move further from the stable state that we are familiar with (“old climate”) to a much warmer world (“new climate”) we will experience worsening weather extremes and a huge “whiplashing” of events (throughout our present “transition period”).

For a notion of whiplashing, consider the Mississippi River. There were record river flow rates from high river basin rainfall in 2011, followed by record drought and record low river water levels in December, 2012 making it necessary for the U.S. Army Corp of Engineers to hydraulically break apart rock on the riverbed to keep the countries vital economic transportation link open to barge traffic. Then, 6 months later, the river was back up to record levels. Incredible swings of fortune.

Mitigation at a global level is dysfunctional and inadequate

Adaption has not worked out too well for Calgary, or Toronto, or Colorado, or numerous other places. Let us not be surprised when a similar torrential rain event hits Ottawa, or Vancouver, or even the Alberta tar sand tailing ponds. In Alberta, tailings ponds would be breached and the toxic waters would overflow the Athabasca River and carry the pollutants up into the north to exit into the Arctic Ocean. Such an event would be catastrophic to the environment and economy of Canada.

How can this risk be ignored? Will the latest IPCC (Intergovernmental Panel on Climate Change) report AR5 released on September 27th once again be ignored by society?


Paul Beckwith is a part-time professor with the laboratory for paleoclimatology and climatology, department of geography, University of Ottawa. He teaches second year climatology/meteorology. His PhD research topic is “Abrupt climate change in the past and present.” He holds an M.Sc. in laser physics and a B.Eng. in engineering physics and reached the rank of chess master in a previous life.

Thursday, August 8, 2013

The Social Tipping Point



by Paul Beckwith

Abrupt Climate Change is happening today, big time!

Abrupt climate change. It is happening today, big time. The northern hemisphere atmospheric circulation system is doing its own thing, without the guidance of a stable jet stream. The jet stream is fractured into meandering and stuck streaked segments, which are hoovering up water vapor and directing it day after day to unlucky localized regions, depositing months or seasons worth of rain in only a few days, turning these locales into water worlds and trashing all infrastructure like houses, roads, train tracks and pipelines. Creating massive sinkholes and catastrophic landslides. And climate change is only getting warmed up.

In the Arctic methane is coming out of the thawing permafrost. Both on land and under the ocean on the sea floor. The Yedoma permafrost in Siberia is now belching out methane at greatly accelerated rates due to intense warming. The collapsing sea ice in the Arctic Ocean is exposing the open ocean to greatly increased solar absorption and turbulent mixing from wave action due to persistent cyclonic activity. Massive cyclonic activity will trash large portions of the sea ice if positioned to export broken ice via the Fram Strait.

We have lost our stable climate

What does it all mean? There is no new normal? Far from it. We have lost our stable climate. Likely permanently. Rates of change are greatly exceeding anything in the paleorecords. By at least 10x, and more likely >30x. We are heading to a much warmer world. The transition will be brutal for civilization.

Can we avoid this? Stop it? Probably not? At least with climate reality being suppressed by corporations and their government employees. With their relentless push for more and more fossil fuel infrastructure and mining and drilling.

What else can we expect as we negotiate our abrupt transition in climate to a much warmer world?

Craziness, in a nutshell. Temperatures over land surfaces in the far north have been consistently over 25 C for weeks, due to persistent high pressure atmospheric blocks leading to clear skies and unblocked solar exposure. Water temperatures in rivers and streams in the far north have resulted in large fish kills as their ecological mortality thresholds have been exceeded. Many other regions are experiencing strange incidences of animal mortality. Mass migrations of animals towards the poles are occurring on land and sea, at startling rates, in an effort for more hospitable surroundings for survival. Shifting food source distributions is causing even hardier, less vulnerable species to be severely stressed. For example, dolphins are being stranded or dying, birds are dropping out of the sky, and new parasites and bacteria are proliferating with warmer temperatures.

In regions of the world undergoing severe droughts the vegetation and soils are drying and fires are exploding in size, frequency, and severity. Especially hard-hit are large regions of the US southwest, southern Europe, and large swaths of Asia. Who knows if forests that are leveled by fire will eventually be reforested; it all depends on what type of climate establishes in the region.

What about coastal regions around the world and sea levels? Not looking too good for the home team. In 2012 Greenland tossed off about 700 Gt (Gt=billion tons) of sea ice, from both melting and calving. As the ice melts it is darkening from concentrated contaminants being exposed, from much greater areas of low albedo meltwater pools, and from fresh deposits of black carbon ash from northern forest fires. Even more worrying are ominous signs of increasing movement. GPS sensor anchored to the 3 km thick glaciers hundreds of km from the coast are registering increased sliding. Meltwater moulins are chewing through the ice from the surface to the bedrock and are transporting heat downward, softening up the ice bonded to the bedrock and allowing sliding. Eventually, large chunks will slide into the ocean causing tsunamis and abrupt sea level rises. Many regions of the sea floor around Greenland are scarred from enormous calving episodes in the past.

The Social Tipping Point

On a positive note, this knowledge of our changing climate threat is filtering out to greater numbers of the slumbering public that has been brainwashed into lethargy by the protectors of the status quo. As more and more people see the trees dying in their back yards and their cities and houses and roads buckling under unrelenting torrential rains they are awaking to the threat. And there will be a threshold crossed and a tipping point reached in human behavior. An understanding of the reality of the risks we face. And finally global concerted action. To slash emissions. And change our ways. And retool our economies and reset our priorities. And not take our planet for granted.



Paul Beckwith is a part-time professor with the laboratory for paleoclimatology and climatology, department of geography, University of Ottawa. He teaches second year climatology/meteorology. His PhD research topic is “Abrupt climate change in the past and present.” He holds an M.Sc. in laser physics and a B.Eng. in engineering physics and reached the rank of chess master in a previous life.


The above compilation of IPCC and NOAA images is by Peter Carter, who adds the following comment:
I agree. The IPCC in 2007 said: "The concentration of CO2 is now 379 parts per million (ppm) and methane is greater than 1,774 parts per billion (ppb), both very likely much higher than any time in at least 650 kyr (during which CO2 remained between 180 and 300 ppm and methane between 320 and 790 ppb). The recent rate of change is dramatic and unprecedented; increases in CO2 never exceeded 30 ppm in 1 kyr – yet now CO2 has risen by 30 ppm in just the last 17 years."

By definition this is abrupt heating. because atmospheric GHG concentration correlates directly with radiative forcing. CO2 is now 397 ppm and methane is now 1830 ppb ! It follows that the rate of ice being melted will also (as it looks) be unprecedented. The only force we have against mad fossil fuel pushing governments is accountability. They have to be made to face the full terrible consequences of their action on energy and inaction on climate. They are destroying the world.