Showing posts with label feedback. Show all posts
Showing posts with label feedback. Show all posts

Monday, October 28, 2013

How Do We Act in the Face of Climate Chaos?

Guy McPherson


Guy R. McPherson is Professor Emeritus of Natural Resources
and 
Ecology & Evolutionary Biology at University of Arizona.
Below are some (slighly edited) extracts from a post at Guy
McPherson's website: 
summary and update on climate change.




The Warning

As described by the United Nations Advisory Group on Greenhouse Gases in 1990, temperature rise “beyond 1 degree C may elicit rapid, unpredictable and non-linear responses that could lead to extensive ecosystem damage”.

We’ve clearly triggered the types of positive feedbacks the United Nations warned about in 1990. Yet my colleagues and acquaintances think we can and will work our way out of this horrific mess with permaculture (which is not to denigrate permaculture, the principles of which are implemented at the mud hut). Reforestation doesn’t come close to overcoming combustion of fossil fuels, as pointed out in the 30 May 2013 issue of Nature Climate Change. Furthermore, forested ecosystems do not sequester additional carbon dioxide as it increases in the atmosphere, as disappointingly explained in the 6 August 2013 issue of New Phytologist.

Here’s the bottom line: On a planet 4 C hotter than baseline, all we can prepare for is human extinction (from Oliver Tickell’s 2008 synthesis in the Guardian).

John Davies concludes: “The world is probably at the start of a runaway Greenhouse Event which will end most human life on Earth before 2040.” He considers only atmospheric carbon dioxide concentration, not the many self-reinforcing feedback loops described below. 


Positive feedbacks
Positive feedbacks
Methane hydrates are bubbling out the Arctic Ocean (Science, March 2010). According to NASA’s CARVE project, these plumes were up to 150 kilometers across as of mid-July 2013. Whereas Malcolm Light’s 9 February 2012 forecast of extinction of all life on Earth by the middle of this century appears premature because his conclusion of exponential methane release during summer 2011 was based on data subsequently revised and smoothed by U.S. government agencies, subsequent information — most notably from NASA’s CARVE project — indicates the grave potential for catastrophic release of methane. Catastrophically rapid release of methane in the Arctic is further supported by Nafeez Ahmed’s thorough analysis in the 5 August 2013 issue of the Guardian as well as Natalia Shakhova’s 29 July 2013 interview with Nick Breeze (note the look of abject despair at the eight-minute mark).
Warm Atlantic water is defrosting the Arctic as it shoots through the Fram Strait (Science, January 2011).
Siberian methane vents have increased in size from less than a meter across in the summer of 2010 to about a kilometer across in 2011 (Tellus, February 2011)
Drought in the Amazon triggered the release of more carbon than the United States in 2010 (Science, February 2011). In addition, ongoing deforestation in the region is driving declines in precipitation at a rate much faster than long thought, as reported in the 19 July 2013 issue of Geophysical Research Letters.
Peat in the world’s boreal forests is decomposing at an astonishing rate (Nature Communications, November 2011)
Invasion of tall shrubs warms the soil, hence destabilizes the permafrost (Environmental Research Letters, March 2012)
Methane is being released from the Antarctic, too (Nature, August 2012). According to a paper in the 24 July 2013 issue of Scientific Reports, melt rate in the Antarctic has caught up to the Arctic.
Russian forest and bog fires are growing (NASA, August 2012), a phenomenon consequently apparent throughout the northern hemisphere (Nature Communications, July 2013). The New York Times reports hotter, drier conditions leading to huge fires in western North America as the “new normal” in their 1 July 2013 issue. A paper in the 22 July 2013 issue of the Proceedings of the National Academy of Sciences indicates boreal forests are burning at a rate exceeding that of the last 10,000 years.
Cracking of glaciers accelerates in the presence of increased carbon dioxide(Journal of Physics D: Applied Physics, October 2012)
The microbes have joined the party, too, according to a paper in the 23 February 2013 issue of New Scientist
Summer ice melt in Antarctica is at its highest level in a thousand years: Summer ice in the Antarctic is melting 10 times quicker than it was 600 years ago, with the most rapid melt occurring in the last 50 years (Nature Geoscience, April 2013). Although scientists have long expressed concern about the instability of the West Atlantic Ice Sheet (WAIS), a research paper published in the 28 August 2013 of Nature indicates the East Atlantic Ice Sheet (EAIS) has undergone rapid changes in the past five decades. The latter is the world’s largest ice sheet and was previously thought to be at little risk from climate change. But it has undergone rapid changes in the past five decades, signaling a potential threat to global sea levels. The EAIS holds enough water to raise sea levels more than 50 meters.
Surface meltwater draining through cracks in an ice sheet can warm the sheet from the inside, softening the ice and letting it flow faster, according to a study accepted for publication in the Journal of Geophysical Research: Earth Surface (July 2013). It appears a Heinrich Event has been triggered in Greenland. Consider the description of such an event as provided by Robert Scribbler on 8 August 2013:
In a Heinrich Event, the melt forces eventually reach a tipping point. The warmer water has greatly softened the ice sheet. Floods of water flow out beneath the ice. Ice ponds grow into great lakes that may spill out both over top of the ice and underneath it. Large ice damns (sic) may or may not start to form. All through this time ice motion and melt is accelerating. Finally, a major tipping point is reached and in a single large event or ongoing series of such events, a massive surge of water and ice flush outward as the ice sheet enters an entirely chaotic state. Tsunamis of melt water rush out bearing their vast floatillas (sic) of ice burgs (sic), greatly contributing to sea level rise. And that’s when the weather really starts to get nasty. In the case of Greenland, the firing line for such events is the entire North Atlantic and, ultimately the Northern Hemisphere.
Breakdown of the thermohaline conveyor belt is happening in the Antarctic as well as the Arctic, thus leading to melting of Antarctic permafrost (Scientific Reports, July 2013)
Loss of Arctic sea ice is reducing the temperature gradient between the poles and the equator, thus causing the jet stream to slow and meander. One result is the creation of weather blocks such as the recent very high temperatures in Alaska. As aresultboreal peat dries and catches fire like a coal seam. The resulting soot enters the atmosphere to fall again, coating the ice surface elsewhere, thus reducing albedo and hastening the melting of ice. Each of these individual phenomena has been reported, albeit rarely, but to my knowledge the dots have not been connected beyond this space. The inability or unwillingness of the media to connect two dots is not surprising, and has been routinely reported (recently including here with respect to climate change and wildfires) (July 2013)
Earthquakes trigger methane release, and consequent warming of the planet triggers earthquakes, as reported by Sam Carana at Arctic-news (October 2013)
Arctic drilling was fast-tracked by the Obama administration during the summer of 2012
Supertankers are taking advantage of the slushy Arctic, demonstrating that every catastrophe represents a business opportunity, as pointed out by Professor of journalism Michael I. Niman and picked up by Truthout (ArtVoice, September 2013)
As nearly as I can distinguish, only the latter feedback process is reversible at a temporal scale relevant to our species. Once you pull the tab on the can of beer, there’s no keeping the carbon dioxide from bubbling up and out. These feedbacks are not additive, they are multiplicative. Now that we’ve entered the era of expensive oil, I can’t imagine we’ll voluntarily terminate the process of drilling for oil and gas in the Arctic (or anywhere else). Nor will we willingly forgo a few dollars by failing to take advantage of the long-sought Northwest Passage.

Robin Westenra provides an assessment of these positive feedbacks at Seemorerocks on 14 July 2013. It’s worth a look.


Earth-system scientist Clive Hamilton concludes in his April 2013 book Earthmasters that “without [atmospheric sulphates associated with industrial activity] … Earth would be an extra 1.1 C warmer.” In other words, collapse takes us directly to 2 C within a matter of weeks. 

Several other academic scientists have concluded, in the refereed journal literature no less, that the 2 C mark is essentially impossible (for example, see the review paper by Mark New and colleagues published in the 29 November 2010 issue of the Philosophical Transactions of the Royal Society A). 

The German Institute for International and Security Affairs concluded 2 June 2013 that a 2 C rise in global-average temperature is no longer feasible (and Spiegel agrees, finally, in their 7 June 2013 issue), while the ultra-conservative International Energy Agency concludes that, “coal will nearly overtake oil as the dominant energy source by 2017 … without a major shift away from coal, average global temperatures could rise by 6 degrees Celsius by 2050, leading to devastating climate change.” 

Image from: The two epochs of Marcott, by Jos Hagelaars

At the 11:20 mark of this video, climate scientist Paul Beckwith indicates Earth could warm by 6 C within a decade. 

If you think his view is extreme, consider: 
  1. the 5 C rise in global-average temperature 55 million years ago during a span of 13 years (reported in the 1 October 2013 issue of Proceedings of the National Academy of Sciences); and also 
  2. the reconstruction of regional and global temperature for the past 11,300 years published in Science in March 2013. One result is shown in the above figure.

How Do We Act in the Face of Climate Chaos?

Below is a video of a recent presentation by Guy McPherson. 

Presentation by Guy McPherson in Boulder, Colorado on October 16, 2013.

Below are some extracts from the video, again slightly edited.

Malcolm Light in 2012 concluded, based on data from NOAA and NASA, that methane release had gone exponential and was leading to the demise of all life on Earth, not just human extinction, by the middle of the century.

So 3.5 C to 4 C is almost certainly a death sentence for all human beings on the planet, not because it'll be a warmer planet, but because the warming of the planet will remove all habitat for human beings. Ultimately we're human animals like other animals, we need habitat to survive.

Changes we see in three or four decades happen as a result of what we do today. There's a huge lag between our actions today in the consequences down the road in terms of the Earth's planetary systems.

Without plankton in the ocean, there goes roughly half the global food supply. The ability to lose land plants is growing rapidly and there goes the other half for the food supply for human beings. If we have up to 5 C by 2050, that'll certainly do the trick.

Why is this happening? It's civilization that drove us into population overshoot. We cannot go back anymore since 1939, since we invented nuclear armageddon. There's no going back. If we ceased the set of living arrangements at this point, the world's 400 or so nuclear power plants melt down catastrophically and we're all dead in a month. We cannot terminate industrial civilization until we decommission all nuclear power plants. It takes at least 20 years to decommission a nuclear power plant.

The bad news is that means that the world's four hundred or so nuclear power plants meltdown catastrophically in a short period of time. Fukushima represent a major threat to humanity. If they fail in moving the spent fuel rods next month, according to nuclear researcher Christina Consola, if one of those MOX fuel rods is exposed to the air, one of the 1565, it will kill 2.89 billion people on the planet in a matter of weeks, so nuclear catastrophe is right there on the horizon. 

People ask me: Why are you presenting this horrible information?

Action is the antidote to despair even if the action is hopeless. When a medical doctor knows that somebody has cancer, it's malpractice if they don't tell that. So I'm doing that. I think Bill McKibben and James Hansen and a whole bunch of climate scientists are guilty of malpractice. Because they know what I know. Almost every politician in the country knows what I know. All the leaders of the big banks know what I know. And they're lying to us.

I'm just presenting the information from other scientists here. I'm trying to the widest extent possible not to infuse my opinion in the situation. It's John Davies who on September 20, 2013, taking into account only carbon dioxide, says there will be few people left on the planet by 2040. It's Malcolm Light, writing in February 2012, who assesses the methane situation. And so on.

Yes, I agree with them, and that agreement is illustrated by me showing you that information.

I promote resistance against this omnicidal culture, not in the hope that it will save our species, but in the hope that it will save other species. Because as E.O. Wilson, biologist at Harvard, points out, it only takes 10 million years after a great extinction event, before you have a blossoming full rich planet again. That's what we're working toward. We're saving habitat for other species at this point.


Tuesday, October 8, 2013

Abrupt Climate Change

What is Abrupt Climate Change?

Abrupt climate change is defined by the IPCC as a large-scale change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades, and causes substantial disruptions in human and natural systems.

Examples of components susceptible to such abrupt change are clathrate methane release, tropical and boreal forest dieback, disappearance of summer sea ice in the Arctic Ocean, long-term drought and monsoonal circulation.

Deposits of methane clathrates below the sea floor are susceptible to destabilization via ocean warming.

Anthropogenic warming will very likely lead to enhanced methane emissions from both terrestrial and oceanic clathrates.

Above extracted from:
- Intergovenmental Panel on Climate Change (IPCC), AR5 Workgroup 1, Technical Summary

New Finding Shows Climate Change Can Happen in a Geological Instant

The Paleocene/Eocene thermal maximum (PETM) is a climate shift that occurred 55 million years ago.

James Wright, Rutgers University Research News -
Morgan Schaller, James Wright, and the core sample
that helped them understand what happened
– and how fast it happened – 55 million years ago.
In a new paper in the Proceedings of the National Academy of Sciences, Morgan Schaller and James Wright present their finding that climate change can and did happen abruptly, or in geological terms, instantaneously.

Following a doubling in carbon dioxide levels, the surface of the ocean turned acidic over a period of weeks or months and global temperatures rose by 5 degrees centigrade – all in the space of about 13 years.

“We’ve shown unequivocally what happens when CO2 increases dramatically – as it is now, and as it did 55 million years ago,” James Wright said.

The film below goes into more detail regarding the current situation.

New Film: Last Hours

The film “Last Hours” describes a science-based climate scenario where a tipping point to runaway climate change is triggered by massive releases of frozen methane. Methane, a powerful greenhouse gas, has already started to percolate into the open seas and atmosphere from methane hydrate deposits beneath melting arctic ice, from the warming northern-hemisphere tundra, and from worldwide continental-shelf undersea methane pools.

“Last Hours” is narrated by Thom Hartmann and directed by Leila Conners. Executive Producers are George DiCaprio and Earl Katz.


For more, also watch some of Thom Hartmann’s interviews.

High Methane Levels persist over Arctic Ocean

High methane levels are prominent over the Arctic Ocean, as illustrated by the image below, covering a period from October 3, 2013, 10:54 am to October 7, 2013, 11:53 pm. The fact that methane has not been present elsewhere in such high concentrations over this period indicates that the methane wasn't carried there by the wind from elsewhere. Also, methane typically appears to move along the same latitude, due to the Coriolis effect.


The image indicates a link between seismic activity and destabilization of methane that is held in sediments under the Arctic Ocean. Methane does show up prominently along the fault line that crosses the Arctic Ocean and extends into Siberia over the Laptev Sea.

The Diagram that IPCC failed to include in AR5

The diagram below shows global warming evolving into accelerated warming in the Arctic. Feedbacks such as albedo changes and methane release speed up this process, triggering abrupt climate change and finally extinction.

The Diagram the IPCC failed to include in AR5

This threatening situation calls for an Effective and Comprehensive Climate Plan, such as depicted by the green lines of action in the image below and as further described at the ClimatePlan blog. For more background, see related posts further below.




Related posts

- Just do NOT tell them the monster exists
http://arctic-news.blogspot.com/2013/10/just-do-not-tell-them-the-monster-exists.html

- Methane Release caused by Earthquakes
http://arctic-news.blogspot.com/2013/09/methane-release-caused-by-earthquakes.html

- Climate Plan
http://climateplan.blogspot.com



Friday, August 16, 2013

Four Hiroshima bombs a second: how we imagine climate change

Hiroshima bomb - from: Wikipedia image
Where does the excess heat go that is trapped in our atmosphere by greenhouse gases every day?

The title of this post is a hat-tip to David Holmes, Monash University, Australia, who recently published an article with that title at The Conversation, discussing that the daily excess heat absorbed by Earth equals the heat released by well over four Hiroshima bombs every seconds.

It's actually well over four Hiroshima bombs every second, given that there are 86,400 seconds in a day and based on James Hansen calculations (at a Feb 29, 2013, TED presentation) that the current imbalance of 0.6 watts/square meter (which does not include the energy already used to cause the current warming of 0.8°C) was equivalent to exploding 400,000 Hiroshima atomic bombs every day, 365 days per year.

As illustrated by the graph below, most of this excess heat is absorbed by oceans and ice. Some of the heat is consumed by the process of melting ice into water, but most heat ends up warming up the oceans.
Graph by Sceptical Science
An earlier post (September 2012, added underneath) described the study by Nuccitelli et al. that measures heat going into the oceans in Joules and, as discussed above, measuring excess heat in terms of heat released by nuclear bombs might give more meaning to what is going on.

Where does the extra heat go? 

Global warming is causing Earth to heat up. As shown on 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.





Warming of water in the Arctic Ocean

Global warming is heating up the oceans big time. As the image below shows, the global ocean heat content has been rising for many years.



White arrows mark ice drift directions. Red arrows mark 
the transport path of warm Atlantic water entering the 
Arctic where it submerges under the cold, ice-covered 
surface layer. Robert Spielhagen (IFM-GEOMAR, Kiel)
The Arctic is affected in particular by the Thermohaline Circulation.

Water flowing into the Arctic Ocean from the Atlantic Ocean is about 2°C warmer today than it has been for at least 2,000 years, according to a study published in Science. The current of warm water lies 50 metres below the surface, and can reach 6°C in summer — warm compared to Arctic surface waters, which can be -2°C.

At the same time, cold water and sea ice are driven out of the Arctic Ocean, along the edges of Greenland. The net result is a marked increase in the temperature of the water in the Arctic Ocean, especially the top layer of the water which causes the sea ice to melt.

The Arctic radiates comparatively less heat into space

Furthermore, cold layers of air close to the surface of the Arctic Ocean make it difficult for infrared radiation to go out to space, according to a study published in Science. These layers do warm up, but warming of these layers is directed downwards, thus amplifying warming in the Arctic.

Surface air temperatures in the Arctic are rising rapidly

Anomalies for surface air temperatures are higher in the Arctic than anywhere else on Earth. The increase in temperature anomalies appears to be an exponential rise. This is caused not only by the above-described points, but also by feedback effects as further described below.

How much will temperatures rise?
In the above graph, rising temperatures are compared to the global average for the period 1951-1980, which is typically used as a base period by NASA in temperature change analysis. The background behind this is that the U.S. National Weather Service uses a three-decade period to define "normal" or average temperature. The NASA Goddard Institude for Space Studies (GISS) analysis of temperature anomalies began around 1980, so the most recent 30 years at the time was 1951-1980.

The study 'Climate Impact of Increasing Atmospheric Carbon Dioxide', by NASA scientists led by James Hansen, describes those early efforts and was published in Science back in 1981. The image below is from the paper, showing that much of the extra heat trapped by carbon dioxide released by people in the atmosphere ends up in oceans.


The paper discusses how many years it can take for oceans to warm up, and the role of feedbacks in that process. The paper notes that a surface albedo change over land areas of 5% (equivalent to a 1.5% global change), would affect global temperature by 1.3°C, adding that paleclimatic evidence suggests that surface warming at high latitudes will be two to five times the global mean warming, due to snow/ice albedo feedback and greater atmospheric stability, which magnifies the warming of near-surface layers.

Feedbacks further accelerate warming in the Arctic

Feedbacks are described in more detail in posts such as Diagram of Doom (image below) and Changes to Polar Vortex affect mile-deep ocean circulation patterns.

Diagram of Doom
One such feedback is albedo change — retreat of Arctic sea ice results in less sunlight being reflected back into space, as further discussed in Albedo Change in the Arctic. Loss of Arctic sea ice is effectively doubling mankind's contribution to global warming. Increased absorption of the sun's rays is the equivalent of about 20 years of additional CO2 being added by man, Professor Peter Wadhams said in a BBC article.

One of the most threatening feedbacks is release of methane that are held in the currently frozen seabed. As the seabed warms up, it starts to release methane in what can be rather abrupt ways. Due to methane's high global warming potential and low levels of hydroxyl in the Arctic, this threatens to further accelerate local warming and trigger further methane releases, in a vicious spiral of runaway global warming.

from: Methane Hydrates

This situation calls for comprehensive and effective action as discussed at the climateplan blog.

Related

- Accelerated Warming in the Arctic 

- Arctic Ocean is turning red

- How much will temperatures rise?

- Methane Hydrates

Sunday, August 4, 2013

Methane as high as 2349 ppb


Earth is undergoing one of the largest climate changes in the past 65 million years, Stanford climate scientists Noah Diffenbaugh and Chris Field report, and it's on pace to occur at a rate 10 times faster than any change in that period.

“We know from past changes that ecosystems have responded to a few degrees of global temperature change over thousands of years,” said Diffenbaugh. “But the unprecedented trajectory that we're on now is forcing that change to occur over decades.”

Some of the strongest evidence for how the global climate system responds to high levels of carbon dioxide comes from paleoclimate studies. Fifty-five million years ago, carbon dioxide in the atmosphere was elevated to a level comparable to today. The Arctic Ocean did not have ice in the summer, and nearby land was warm enough to support alligators and palm trees. But apart from the rate of change, Diffenbaugh adds, another key difference is that “today there are multiple human stressors that were not present 55 million years ago, such as urbanization and air and water pollution.”

By the end of the century, should the current emissions of greenhouse gases remain unchecked, temperatures over the northern hemisphere will tip 5-6 degrees C warmer than today's averages. In this case, the hottest summer of the last 20 years becomes the new annual norm.

The situation looks to be even more dire than that, argues Sam Carana. In addition to carbon dioxide, there are further pollutants driving global warming. Moreover, as pictured below, feedbacks can dramatically accelerate the rise in temperature locally, particularly in the Arctic.

Image 21. For more details on feedbacks, see extended version of this image and discussion at

The level of methane in the atmosphere has already been rising even faster than the level of carbon dioxide, as illustrated by the image below. Moreover, there's the threat that large additional amounts of methane will suddenly be released, in particular from the Arctic seabed.


In August 2013, methane were recorded as high as 2349 ppb, as illustrated by the graph on below (added later, editor), showing that in early August, the world's mean methane level suddenly increased with at least 10 ppb compared to mean levels over the past few months.




To get an idea just how much methane has entered the atmosphere, have a look at the image below, covering several days from the start of August 2013.

[ click on image to enlarge ]


This is further illustrated by the two images below. The image directly below shows where the highest methane levels (i.e. over 1950 ppb, in yellow) were recorded on August 2, 2013.

[ click on image to enlarge ]
The image below shows the presence of methane on August 2, 2013, for a number of ranges, including at levels over 1950 ppb (this time in red).

[ click on image to enlarge ]
The methane threat is further described in the post Methane hydrates, which also features the image below.


Methane as high as 2303 ppb

This post has been updated as Methane as high as 2349 ppb.

Friday, December 28, 2012

Albedo changes in the Arctic

How global warming and feedbacks are causing huge albedo changes in the Arctic.

Snow cover decline

Decline of the snow cover on land in the northern hemisphere is accelerating, as illustrated by the image below and the image underneath on the right. (1)


Image credit: Rutgers University
Fresh snow can have an albedo as high as 0.85, meaning that up to 85% of the sunlight falling on snow can get reflected back into space. As the snow melts, its structure changes making it less reflective, i.e. its albedo will go down, to as low as 40%. (2)

As a result, more sunlight gets absorbed, accelerating the melting process. Eventually, where snow melts away, spots of bare soil become exposed, and dark wet soil has a very low albedo, reflecting only between 5% and 15% of the sunlight. Thus, even more sunlight gets absorbed and the soil's temperature increases, causing more of the remaining snow to melt. (2)

Changes in vegetation can further accelerate this process. Russia's boreal forest - the largest continuous expanse of forest in the world - has seen a transformation in recent years from larch to conifer trees. Larch trees drop their needles in the fall, allowing the vast, snow-covered ground in winter to reflect sunlight and heat back into space and helping to keep temperatures in the region very cold. But conifers such as spruce and fir retain their needles, which absorb sunlight and increase the forest's ground-level heat retention. (3)

Albedo, from Wikipedia
A conversion from larch to evergreen stands in low-diversity regions of southern Siberia would generate a local positive radiative forcing of 5.1±2.6 W m−2. This radiative heating would reinforce the warming projected to occur in the area under climate change. (4)

Tundra in the Arctic used to be covered by a white blanket of snow most of the year. However, as the landscape is warming up, more trees and shrubs appear. Scientists who studied part of the Eurasian Arctic, found that willow and alder shrubs, once stunted by harsh weather, have been growing upward to the height of trees in recent decades. They now rise above the snowfall, presenting a dark, light-absorbing surface. This increased absorption of the Sun's radiation, combined with microclimates created by forested areas, adds to global warming, making an already-warming climate warm even more rapidly. (5 & 6)

Furthermore, encroachment of trees onto Arctic tundra caused by the warming may cause large release of carbon to the atmosphere, concludes a recent study. This is because tundra soil contains a lot of stored organic matter, due to slow decomposition, but the trees stimulate the decomposition of this material. (7)


Sea ice decline

In the Arctic, sea ice volume has fallen dramatically over the years, as illustrated by the image on the right. The trend points at 2014 as the year when Arctic sea ice will first reach zero volume for some time during that year. (8)

The Arctic Ocean looks set to be ice-free for a period of at least three months in 2015 (August, September and October), and for a period of at least 6 months from the year 2020 (June through to November). (9)

Decline of the Arctic sea ice is accelerating, due to numerous feedbacks. As the Arctic atmosphere warms up, any snow cover on top of the ice will melt away ever quickly, decreasing the surface albedo and thus reinforcing the warm-up. As melt ponds appear on top of the ice, the albedo will drop even further.

Sam Carana's Diagram of Doom pictures ten feedbacks that jointly work to accelerate sea ice decline. (10)

The image below shows the three areas where albedo change will be felt most in the Arctic, i.e. sea ice loss, decline of albedo in Greenland and more early and extensive retreat of snow and ice cover in other areas in the Arctic. (8)

Big changes in the Arctic within years, by Sam Carana


References

1. Northern Hemisphere Snow Cover Anomalies 1967-2012 June, Rutgers University
climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=6

2. Albedo, Albedo Change blog
albedochange.blogspot.com/2009/02/albedo-change.html

3. Shift in Northern Forests Could Increase Global Warming, Scientific American, March 28, 2011
scientificamerican.com/article.cfm?id=shift-northern-forests-increase-global-warming

4. Sensitivity of Siberian larch forests to climate change, Shuman et al., April 5, 2011, Wiley.com
onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2011.02417.x/abstract

5. Warming turns tundra to forest
ox.ac.uk/media/news_stories/2012/120604.html

6. Eurasian Arctic greening reveals teleconnections and the potential for structurally novel ecosystems, Macias-Fauria et al., 2012
nature.com/nclimate/journal/v2/n8/full/nclimate1558.html

7. Expansion of forests in the European Arctic could result in the release of carbon dioxide, University of Exeter news, June 18, 2012
exeter.ac.uk/news/featurednews/title_214902_en.html

8. Big changes in the Arctic within years, Sam Carana, October 26, 2012, Arctic-News blog
arctic-news.blogspot.com/2012/10/big-changes-in-arctic-within-years.html

9. Getting the Picture, Sam Carana, August 2012, Arctic-News blog
arctic-news.blogspot.com/2012/08/getting-the-picture.html

10. Diagram of Doom, Sam Carana, August 2012, Arctic-News blog
arctic-news.blogspot.com/2012/08/diagram-of-doom.html


Further reading

- Albedo change in the Arctic
arctic-news.blogspot.com/2012/07/albedo-change-in-arctic.html

- Greenland is melting at incredible rate
arctic-news.blogspot.com/2012/07/greenland-is-melting-at-incredible-rate.html

- Albedo change in the Arctic threatens to cause runaway global warming
arctic-news.blogspot.com/2012/10/albedo-change-in-the-arctic-threatens-to-cause-runaway-global-warming.html

Thursday, December 20, 2012

Polar jet stream appears hugely deformed


World climate zones used to be kept well apart by jet streams. On the northern hemisphere, the polar jet stream was working hard to separate the Tundra and Boreal climate zones' colder air in the north from the Temperate climate and the Subtropical climate zones' warmer air in the south.

NOAA image
The greater the difference in temperature between north and south, the faster the jet streams spin around the globe, the polar jet stream at about 60°N and the subtropical jet stream at about 30°N, as illustrated on above image. 

NOAA image
The polar jet stream used to move at speeds of up to 140 miles per hour, while following a relatively straight track that was meandering only slightly, i.e. with waves that go up and down only a little bit.

Accordingly, the Northern Temperate Zone used to experience only mild differences between summer and winter weather, rather than the extreme hot or cold temperatures that we've experienced recently.

Accelerated warming in the Arctic is decreasing the difference in temperature between the Arctic and the Northern Temperate Zone. This is causing the polar jet to slow down and become more wavy, i.e. with larger loops, as illustrated by the NASA image further below.
Polar jet stream (blue) & subtropical
jet stream (red) - NOAA image

                   Diagram of Doom, Sam Carana
This is a feedback of accelerated warming in the Arctic that reinforces itself. As the jet stream slows down and its waves become more elongated, cold air can leave the Arctic more easily and come down deep into the Northern Temperate Zone. Conversily, more warm air can at the same time move north into the Arctic.

The 'open doors' feedback further decreases the difference in temperature between the Arctic and the Northern Temperate Zone, in turn further slowing down the jet stream and making it more wavy, and thus further accelerating warming in the Arctic.

The polar jet stream can travel at speeds greater than 100 mph. Here, the fastest winds are colored red; slower winds are blue. View animated version here. Credit: NASA/Goddard Space Flight Center
How does this affect temperatures? If we look at the average surface temperature anomalies for the month November 2012, we see huge differences in temperatures. Areas in the East Siberian Sea and in east Siberia registered average surface temperature anomalies for November 2012 of about 10 degrees Celsius, compared with 1951-1980. At the same time, areas in Alaska and Canada have been experiencing anomalies of about -10 degrees Celsius.


This suggests a hugely deformed polar jet stream, as indicated by the contour lines on above image on the right. This is very worrying, as this is only one out of many feedbacks that come with accelerated warming in the Arctic. There are at least ten such feedbacks, as depicted in the diagram below, from the earlier post Diagram of Doom.

       Diagram of Doom, Sam Carana
One of the most frightening feedbacks is the albedo loss in the Arctic. The speed at which changes are taking place can be illustrated with the image below, from the earlier post Big changes in the Arctic within years.



The urgency to act is perhaps best expressed by means of the two images below, which can constitute a fitting end-of-year message if you like to share them further. The image below highlights that Arctic sea ice minimum volume in 2012 was only 19.3% what it was in 1979. The background image, prepared by Wipneus, shows an exponential trend projecting a 2013 minimum of only 2000 cubic km of sea ice, with a margin of error that allows Arctic sea ice to disappear altogether next year, i.e. nine months from now.

Finally, the image below highlights that, in 2012, Arctic sea ice area fell by 83.7% in just 168 days, again illustrating how fast things can eventuate. 


For more quotes, see the page at http://arcticmethane.blogspot.com/p/quotes.html

Earlier posts:
Opening the Doorways to Doom

Friday, October 26, 2012

Hurricane Sandy moving inland

Hurricane Sandy is moving inland and its impact is forecast to be felt as far away as in Toronto and Ottawa.

Coastal Watches/Warnings and 5-Day Track Forecast Cone
Hurricane SANDY Advisory #019       11:00 PM EDT Fri October 26, 2012
from:  National Hurricane Center (check link for updates!)



Paul Beckwith,
B.Eng, M.Sc. (Physics),
Ph.D. student (Climatology)
and Part-time Professor,
University of Ottawa
 
This prompted Paul Beckwith to make the following comments:

All storms veer to the right in the northern hemisphere due to the spinning of the earth (1 revolution per day). Except when there is a tilted high pressure region northward and it has to go left and there is a massive low pressure region left that sucks it there as well. 

Why the high pressure ridge and massive low pressure? Because the jet stream is wavier and slower, a situation that is happening more and more often, because of massive sea ice decline this summer. Which is due to Arctic amplification feedbacks. Which in turn is due to rising greenhouse gases. Which is due to humans.

The situation is further illustrated by the image below, from ClimateCentral.

An atmospheric "blocking pattern" will push Sandy north, then northwestward, into the Mid-Atlantic or Northeast. Click to enlarge the image.     Credit: Remik Ziemlinski, Climate Central.
In an earlier post, Paul Beckwith described that a very rare cyclone churned up the entire Arctic region for over a week in early August 2012, destroying 20% of the ice area by breaking it into tiny chunks, melting it, or spitting it into the Atlantic. Cold fresh surface water from melted sea ice mixed with warm salty water from a 500 metre depth! Totally unexpected. A few more cyclones with similar intensity could have eliminated the entire remaining ice cover. Thankfully that didn't happen. What did happen was Hurricane Leslie tracked northward and passed over Iceland as a large storm. It barely missed the Arctic this time. Had the storm tracked 500 to 600 kilometres westward, Leslie would have churned up the west coast of Greenland and penetrated directly into the Arctic Ocean basin.

We dodged a bullet, at least this year. This luck will surely run out. What can we do about this? How about getting our politicians to listen to climatologists, for starters.

Below, rainfall forecast from the Hydrometereological Prediction Center of the National Weather Service - check the link for updates! 




Related

- Vanishing Arctic sea ice is rapidly changing global climatearctic-news.blogspot.com/2012/09/vanishing-arctic-sea-ice-is-rapidly-changing-global-climate.html

- Storm enters Arctic region

- Huge cyclone batters Arctic sea ice
arctic-news.blogspot.com/2012/08/huge-cyclone-batters-arctic-sea-ice.html