Saturday, June 11, 2011

Earth at Boiling Point

Silence before the Storm


Here's an analogy to describe the precarious situation we're in. When heat is added to water at boiling point (100°C or 212°F), vapor will appear at the surface, while bubbles of gas are formed throughout the water, but the water's temperature will not rise. All added energy is absorbed in the water, transforming it from a liquid to a gas. This is illustrated by the image below, adapted from ilpi.com.
Similarly, Earth is now at boiling point, i.e. the situation has reached a point where - at first glance - it may appear as if there's little or no change. Rises in global temperature, as illustrated by the chart below, based on data by the National Oceanic and Atmospheric Administration (NOAA) with standard polynomial trendline added, may seem only mild.

Many will hardly notice global warming, due to the variability of short-term weather conditions locally.
Furthermore, we’ve had a strong La NiƱa, which pushes temperatures down, while we’ve been in a solar minimum, as some call it: “the deepest solar minimum in nearly a century”. 
As the image on the right shows, differences in irradiation can amount to a difference in warming of up to 0.25 W/m2
So, impressions that the impact of global warming was only mild can be deceptive.  
The NOAA image below shows a steady increase in carbon dioxide over the years. At the same time, the image also shows little or no increase at all for some other emissions over the past decade, particularly for methane (CH4). 

Again, such impressions can be deceptive, as this may make people assume that methane will continue to show little or no increase in future. Instead, the boiling-point analogy is more appropriate to describe the situation regarding methane. Similar to bubbles that start forming in water at boiling point, methane bubbles are forming in the Arctic.


Arctic Sea Ice losses


At the European Geosciences Union annual meeting, Professor Wieslaw Maslowski, who works at Naval Postgraduate School in Monterey, California, unveiled the results of advanced computer modeling that produces a "best guess" date of 2016 for Arctic waters to be ice-free in summers. The study follows his team's 2007 projection that the dramatic loss of ice extent in 2007 set the stage for Arctic waters to be ice-free in summers within just 5-6 years.
Also illustrative is the image below, from Arctic Sea Ice Blog.


Feedback Effects in the Arctic


Disappearing sea ice will cause albedo changes in the Arctic, amplifying the warming taking place there. The color of the sea is darker than the ice that previously covered it.

Another albedo change is taking place on land. The forested landscape in Siberia may over the course of a year absorb between 2 and 7% more solar radiation, reinforcing local warming trends. 
Temperature rises are further amplified by additional feedback effects such as releases of nitrous oxide and methane. 
So, while it may appear that there has been little or no rise in methane for some time, the prospect of future methane emissions looks very scary. 
Due to amplification of global warming in the Arctic, temperatures can now be 10°C or 18°F higher than average temperatures were 1951-1980 (NASA image left).. 
Most methane emissions occur at the northern hemisphere's high latitudes (Wikipedia image below).



At first glance, it may seem as if there's nothing to worry about. Methane releases have historically been stronger at high latitudes of the northern hemisphere, as  illustrated by the NOAA image left (with Mauna Loa data highlighted in red). 
However, levels of methane in the Arctic can be expected to rise dramatically, as discussed below.
The image below shows the current extent of Arctic permafrost, as part of a study by Edward Schuur that estimates that there is some 1672 petagrams (GT or billion metric tons, see table below) of carbon in the Arctic permafrost - roughly equivalent to a third of all carbon in the world's soils and about twice the amount of carbon contained in the atmosphere.

The figures mentioned in above paragraph were also used in the report by the Copenhagen Diagnosis, where authors further pointed at the amplifying feedback effect in high northern latitudes of microbial transformation of nitrogen trapped in soils to nitrous oxide.
Apart from Arctic releases of carbon dioxide, there is the potential for releases of nitrous oxide and methane. Much methane is also present in Arctic waters and in sediments underneath the water. Due to methane's high initial global warming potential (GWP), large abrupt releases of methane could lead to runaway global warming, as further discussed below.
The terrifying prospect is that, within a time-span of only a few years, huge methane releases in the Arctic will spread around the globe, covering Earth in a heat-trapping blanket and moving our biosphere beyond its biological boiling point.
Units of measurement
Multiple  NameSymbol
  English           Multiple (SI)Name (SI)Symbol (SI)English(SI)
                                   100gramggram
                                    103kilogramKgthousand g 
 100tonne     t 1 tonne                   106megagramMgmillion g 
 103kilotonne    kt 1 thousand tonnes   109gigagramGgbillion g 
 106megatonne    Mt 1 million tonnes       1012teragramTtrillion g 
 109gigatonne    Gt 1 billion tonnes        1015petagramPgquadrillion g
   1012teratonne    Tt 1 trillion tonnes        1018exagramEg
   1015petatonne    Pt 1 quadrillion tonnes  1021zettagramZg
   1018exatonne    Et                               1024yottagramYg


Methane's Global Warming Potential (GWP)


The image below, from the Intergovernmental Panel on Climate Change (IPCC), shows that methane levels have already been rising dramatically since the industrial revolution.


Over the years, the IPCC has upgraded methane's global warming potential (GWP). In 1995, the IPCC used a figure of 56 for methane's GWP over 20 years, i.e. methane being 56 times more powerful than carbon dioxide by weight when comparing their impact over a period of 20 years. In 2001, the IPCC upgraded methane's GWP to 62 over 20 years, and in 2007 the IPCC upgraded methane's GWP to 72 over 20 years.
Large releases could make that much of the methane could remain in the atmosphere longer, without getting oxidized. Initially, much of the methane is oxidized in the sea by oxygen (when released from underwater sediments) and in the atmosphere by hydroxyl. Over time, however, accumulation of methane could cause oxygen and hydroxyl depletion, resulting in ever more methane entering the atmosphere and remaining there for a longer period. 
two-part study by Berkeley Lab and Los Alamos National Laboratory shows that, as global temperature increases and oceans warm, methane releases from clathrates would over time cause depletion of oxygen, nutrients, and trace metals needed by methane-eating microbes, resulting in ever more methane escaping into the air unchanged, to further accelerate climate change.


A 2009 study by Drew Shindell et al. shows that chemical interactions between emissions cause more global warming than previously estimated by the IPCC. The study shows that increases in global methane emissions have already caused a 26% decrease in hydroxyl (OH). Because of this, methane now persists longer in the atmosphere, before getting transformed into the less potent carbon dioxide.
Centre for Atmospheric Science study suggests that sea ice loss may amplify permafrost warming, with an ice-free Arctic featuring a decrease in hydroxyl of up to 60% and an increase of tropospheric ozone (another greenhouse gas) of up to 60% over the Arctic.
Extension of methane's lifetime further amplifies its greenhouse effect, especially for releases that are two or three times as large as current releases. 
The graph on the right, based on data by Isaksen et al. (2011), shows how methane's lifetime extends as more methane is released.
The image below, from a study by Dessus et al., shows how the impact of methane decreases over the years. In the first five years after its release, methane will have an impact more than 100 times as potent as a greenhouse gas compared to carbon dioxide.

The GWP for methane typically includes indirect effects of tropospheric ozone production and stratospheric water vapor production. The study by Isaksen et al. shows (image below) that a scenario of 7 times current methane levels (image below,medium light colors) would correspond with a radiative forcing of 3.6 W/m-2.


Such an increase in methane would thus add more than double the entire current net anthropogenic warming (for comparison, see Wikipedia image below).

For many years, the amount of methane has remained stable at about 5 Gt annually (NOAA image below). A scenario of 7x this amount would lift the amount of methane in the atmosphere to about 35 Gt.
A scenario of seven times the amount of methane we're used to having in the atmosphere would give the methane a lifetime of more than 18 years, so there's no relief from this burden in sight, while this would triple the entire net effect of all emissions added by people since the industrial revolution. 


Arctic concentration makes the situation even worse


What makes things even worse is that all this methane would initially be concentrated in the Arctic, whereas GWP for greenhouse gases is typically calculated under the assumption that the respective greenhouse gas is spread out globally.
All this methane will initially be concentrated locally, causing huge Arctic amplification of the greenhouse effect in summer, when the sun doesn't set. 
The methane will heat up the sea, causing further lack of of oxygen in the water, while algae start to bloom, making this worse, and lack of hydroxyl in the air.
In a vicious circle that will further accelerate the permafrost melt, this will cause further releases from permafrost and clathrates.


Uninhabitable Planet

Back in 2009, I pointed at projections of a MIT study showing that, without rapid and dramatic action on global warming, global median surface temperature will rise by 9.4oF (5.2oC) by 2100.
The wheel on the right depicts the MIT's estimate of the range of probability of potential global temperature rise by 2100 if no policy is enacted on curbing greenhouse gas emissions.
The wheel on the left assumes that aggressive policy is enacted, and projects a lower rise.
The projections show rises ranging up to 13.3oF (7.4oC), based on probabilities revealed by 400 simulations.
But even the worst-case scenario in the above MIT-study may actually understate the problem and the speed with which this may eventuate, since the model does not fully incorporate positive feedbacks such as large-scale melting of permafrost in arctic regions and subsequent release of large quantities of methane.
Several teams of scientists warn that we can expect a rise of 4oC within decades. A rapid rise in temperature is likely to make the areas where most people now live uninhabitable, leaving humans, mammals and plants little on no time to migrate to cooler areas. The image below (edited from New Scientist) shows that the currently inhabited part of the planet would become largely uninhabitable with a global temperature rise of 4oC.
Above image gives some suggestions as to action that can be taken, such as reforestation and construction of clean energy facilities. The image also shows that habitable areas may be restricted to the edges of the world where there's little sunshine. A specific area can become uninhabitable due to sea level rises or heat stress. Humans simply cannot survive prolonged exposure to temperatures exceeding 95°F (35°C), explains Steven Sherwood. An area can also become uninhabitable due to recurring wildfires, floods, droughts, storms and further extreme weather events that cause erosion, desertification, crop losses and shortages of fresh water. 
Back in 2007, I pointed at the danger of tipping points beyond which human beings face the risk of total extinction, particularly if many species of animals and plants that humans depend on will disappear. The boiling point analogy shows that there may be a window of time to act, like a silence before the storm. This realization should prompt us to speed up implementation of the necessary policies while we can. In fact, abrupt large releases of methane may close that window rather quickly, as described in Runaway Global Warming and The potential for methane releases in the Arctic to cause runaway global warming

Saturday, May 28, 2011

Biomass

Traditionally, biomass has been used in four ways:
 1. For industrial purposes (shelter, building materials, furniture, utensils, etc)
 2. Burning (for domestic energy use such as heating, lighting and cooking, and for land clearance) 
 3. Conservation (left on land or added to soil as compost, to enrich soil and biodiversity, avoid erosion, etc.) 
 4. For food (including livestock feed, while using fertilizers and with waste dumped in landfills or sea)


In the light of rising costs of fossil fuel and climate change concerns, other uses are considered, specifically: 
 5. Low-footprint food (reduced meat and reduced use of chemical fertilizers, with waste processed)
 6. Commercial combustion in power plants, furnaces, kilns, ovens and internal combustion engines
 7. Burial 
 8. BECCS (Bio-Energy with Carbon Capture & Storage)
 9. Biochar (Pyrolysis resulting in biochar, syngas and bio-oils)
10. Biochar + BECCS (Biochar + Bio-Energy with Carbon Capture & Storage)

Table 1. Comparison of methods to process biomass (Energy and Carbon)
 Combustion Burial BECCS Biochar Biochar + BECCS
 Energy - year 0  1.0 -0.1 0.8 0.5 0.5
 Carbon - year 0 -0.1  1.0 0.8 0.5 0.9
 Energy - out years 0.4 0.4
 Carbon - out years 0.5 0.5
 Total  0.9  0.9 1.6 1.9 2.3
Above table by Ron Larsen, from this message, shows five methods to process biomass, rated (with 1.0 being the highest score) for their ability to supply energy and for their ability to remove carbon from the atmosphere.  

Above table shows that each way to process biomass waste has advantages and disadvantages:
 6. Combustion may seem attractive for its supply of energy, while having negative impact due to emissions 
 7. Burial can minimize emissions, but it doesn't provide energy, in fact it costs energy
 8. BECCS can score high on immediate energy supply as well as on avoiding carbon emissions
 9. Biochar scores well regarding immediate energy supply and emissions, with additional future benefits
10. Biochar + BECCS has all the benefits of biochar, while also capturing and storing pyrolysis emissions

The table below also incorporates above-mentioned traditional use of biomass, while using a wider footprint, i.e. with scores not only reflecting the ability of the method to remove carbon from the atmosphere, but also looking at emissions other than carbon.

Table 2. Comparison of ten uses of biomass (Energy and Footprint)
Energy - year 0Footprint - year 0Energy - out yearsFootprint - out yearsTotal
Industrial -0.1 0.1 0.0
Burning 1.0-1.0
   0.0
Conservation  -0.2
  -0.2
Food  -0.3 -0.3
Low-footprint food  
 0.0
Combustion 1.0-0.1
 0.9
Burial-0.1 1.0  0.9
BECCS 0.8  0.8 
 1.6
Biochar 0.5  0.50.4   0.5 1.9
Biochar +BECCS 0.5  0.9 0.4   0.5 2.3

Biochar gets its positive "out years" scores for increasing vegetation growth over time, as it improves soil's water and nutrients retention, while also reducing the need for chemical fertilizers. 

These qualities of biochar are also helpful in efforts to bring vegetation into the desert by means of desalinated water, as proposed by a number of scientists. A study by Leonard Ornstein, a cell biologist at the Mount Sinai School of Medicine, and climate modelers David Rind and Igor Aleinov of NASA's Goddard Institute for Space Studies, all based in New York City, concludes that it's worth while to do so.
They envision building desalination plants to pump seawater from oceans to inland desert areas using pumps, pipes, canals and aqueducts. The idea is that this would result in vegetation, with the tree cover also bringing more rain -- about 700 to 1200 millimeters per year -- and clouds, which would also help reflect sunlight back into space.
This would not only make these deserts more livable and productive, it would also cool areas, in some cases by up to 8°C .
Importantly, vegetation in the deserts could draw some 8 billion tons of carbon a year from the atmosphere -- nearly as much as people now emit by burning fossil fuels and forests. As forests matured, they could continue taking up this much carbon for decades.
The researchers estimate that building, running, and maintaining reverse-osmosis plants for desalination and the irrigation equipment will cost some $2 trillion per year.

Monday, April 18, 2011

How would you allocate US$10 million per year to most reduce climate risk?

Imagine that you had a budget of $10 million per year and that you should maximize the amount of climate risk reduction obtainable with that $10 million, what would you allocate it to and why?

Given the scary situation in the Arctic, I would apportion parts of the $10 million to methods that promise immediate results:
  1. R&D and testing of SRM methods such as surface brightening and marine cloud brightening.
  2. R&D and testing of ways to ignite or break down methane from the sky, i.e. from airplanes or satellites. Laser beams spring to mind. Another technology that could be looked at further is to focus short, amplified pulses of light on water vapor, hydrogen peroxide or ozone, in efforts to produce more hydroxyl (OH) which could in turn oxidize as much methane as possible.
  3. Building on the outcome of 2., equipping small aircraft with such technology, as well as autopilot software, GPS, LiPo batteries and with solar thin film mounted both on top of and underneath the wings.
example aircraft
At first, as a test, two such small aircraft could navigate on auto-pilot to the north of Canada and Alaska at the start of Spring on the Northern Hemisphere.

In subsequent years, numerous such planes could follow, also going to other parts of the Arctic. At the end of Summer, the planes could return home for a check-up and possible upgrade of the technology, to be launched again the next year.

There are many self-financed clubs where members build and fly remote controlled aircraft, as discussed in comments underneath this post.

Even a small financial incentive could help such clubs make a lot progress and give them a goal, while the publicity would also make people more aware of the problems we face in the Arctic.

Such aircraft could navigate the Arctic, guided by satellite detection of methane concentrations (image left) and by equipment carried onboard, such as small versions of methane analyzers.

Measuring from different vantage points can pinpoint the most suitable location to cross-aim multiple laser beams at, to minimize the energy needed to heat up methane to its point of auto-ignition (image below).



Methane can be ignited where it is present in concentrations of between 5% and 15%. In concentrations of around 9%, methane could be ignited with as little as 0.3 mj of energy (see image, adapted from Zabetakis).

At well over 500 degrees Celsius, methane's minimum auto-ignition temperature is rather high. Other volatile hydrocarbons in the vicinity may ignite at lower temperatures (with less energy), in turn igniting the methane.



Sam Carana

For further background on the above, also see:
http://geo-engineering.blogspot.com/2011/04/runaway-global-warming.html
and
http://groups.google.com/group/geoengineering/browse_thread/thread/5eaf812314dced8c



Call for action

As a result of emissions of pollutants around the world, massive amounts of greenhouse gases are threatening to be released in the Arctic. This calls for action. In addition to long-term measures to mitigate climate change and remove pollutants from oceans and atmosphere, geoengineering in the Arctic should now be included in our efforts to avoid catastrophe.

Undersigned:

Sam Carana, editor of Geo-engineering.blogspot.com

Comments and further signatories are welcome.


Creative Commons License
Geo-engineering.blogspot.com
Creative Commons License
Please spread this call for action widely,
adding CC and link as footer underneath.




Subscribe to Solar Radiation Geo-Engineering
Google GroupsVisit this group
Email:


 

Friday, April 15, 2011

Runaway Global Warming

1. Methane releases in the Arctic

On June 15, 2011, the research vessel Polarstern (Wikipedia photo right) of the Alfred Wegener Institute for Polar and Marine Research will set off on its 26th arctic expedition.

According to the press release, scientists onboard the vessel plan to take seafloor samples from a marine area in which fishery echosounders recently detected numerous gas flares. They indicate that probably enormous quantities of methane are released from the seafloor at water depths of around 400 metres west of Svalbard.

Scientists have been researching the potential for methane releases in the Arctic for years. One of the dangers with climate change is that hydrates could become destabilized, causing huge amounts of methane to be released, in turn accelerating warming.

The East Siberian Arctic Shelf is a region about 2,000,000 km2 large that, due to polar amplification of global warming, can now be 10°C or 18°F warmer than it was from 1951 to 1980 (NASA image below).

Shakhova and Semiletov (2010) conclude that this ESAS region should be considered the most potential in terms of possible climate change caused by abrupt release of methane.

A press release accompanying a widely-reported study published in Science in 2010 explains that in the shallows of the East Siberian Arctic Shelf, methane simply doesn't have enough time to oxidize, which means more of it escapes into the atmosphere. That, combined with the sheer amount of methane in the region, could add a previously uncalculated variable to climate models.

"The release to the atmosphere of only one percent of the methane assumed to be stored in shallow hydrate deposits might alter the current atmospheric burden of methane up to 3 to 4 times," Shakhova warns.

A 2008 paper by Shakhova et al. considered release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time. Such a release could multiply the atmospheric methane burden by up to 11 times.

2. Abrupt merthane releases

As permafrost melts, algae and bacteria can flourish, contributing methane through their metabolism. Even more worrying, collapse of methane hydrates can cause abrupt release of huge amounts of methane.

Rising temperatures can cause hydrates to collapse, resulting in abrupt release of huge amounts of methane. Anomolies of up to 12.5°C show up on the image below with average temperatures for November 2010.


 

For individual days and locations, the anomaly can be even more striking. On January 6, 2011, the minimum temperature in Coral Harbour, located at the northwest corner of Hudson Bay in the province of Nunavut, Canada, was –3.7°C (25.3°F), i.e. 30°C (54°F) above average.

How high can temperatures rise in the Arctic? Below are projections based on above NASA data. 




Methane hydrates are held together by high pressure and low temperatures. They can collapse when the temperature rises, or when pressure falls, e.g. when hydrates are disturbed by earthquakes and associated tsunamis, shock-waves and land-slides. Thermal expansion of land and water can put additional stress on areas prone to seismic activity. Furthermore, as ice and glaciers in the mountains melt away, a substantial weight is disappearing, changing pressures that act on the Earth's crust and contribute to seismic activity. This link was confirmed in several scientific studies, such as this one dating back to 2003. Drilling and fracking in these hydrates could make things worse and trigger abrupt releases of huge amounts of methane.

Collapse of a single hydrate can accelerate local warming, in turn causing further hydrates to similarly start adding large amounts of methane to the atmosphere, as further described below.

3. Oxygen depletion

At the moment, methane releases from undersea sediments may still become oxidized in the water. However, a two-part study by Berkeley Lab and Los Alamos National Laboratory shows that, as global temperature increases and oceans warm, methane releases from clathrates would over time cause depletion of oxygen, nutrients, and trace metals needed by methane-eating microbes, resulting in ever more methane escaping into the air unchanged, to further accelerate climate change. 

 
4. Hydroxyl depletion in the air

To make matters even more catastrophic, high methane concentrations will result in an absence of enough hydroxyl in the air for all this methane to be oxidized. A 2009 study by Drew Shindell found that increases in global methane emissions did cause a 26% hydroxyl decrease. Because of this, methane now persists longer in the atmosphere, before getting transformed into the less potent carbon dioxide.

A Centre for Atmospheric Science study suggests that sea ice loss may amplify permafrost warming, with an ice-free Arctic featuring a decrease in hydroxyl of up to 60% and an increase of tropospheric ozone (another greenhouse gas) of up to 60% over the Arctic. This lack of hydroxyl means that methane will persist in the atmosphere for longer at its high global warming potency.

5. Local concentration of methane

Earth has 510,072,000 km2 of surface, or more than 255 times that of the East Siberian Arctic Shelf. Initial concentration of that much methane in the Arctic makes things even worse. While methane can spread out quickly, it will initially be concentrated where it is released. A major methane release in the high Arctic would take 15-40 years to spread to the South Pole. This methane will allow less heat from sunlight in summer to escape into space, while the sun doesn't set. This could therefore cause summer temperatures to rise dramatically in the Arctic, in turn causing further melting and more warming than we're already witnessing now.

6. Methane's high initial Global Warming Potential

Particularly worrying about methane is its high global warming potential, which can be made worse due to the above points, i.e. lack of oxygen in water, resulting in ever less methane oxidation in water, hydroxyl depletion in the air and local concentration of methane. All this may increase methane's global warming potential. 


In its first five years, methane is at least 100 times as potent as carbon dioxide as a greenhouse gas (above image below, from a study by Dessus). Abrupt releases of 15 Gt (or Pg) of methane would result in a burden of 20 Gt of methane (since there already is about 5 Gt in the atmosphere). Applying a global warming potential of 100 times carbon dioxide would give this 20 Gt of methane an initial greenhouse effect equivalent to 2000 Pg of carbon dioxide.

By comparison, atmospheric carbon dioxide levels rose from 288 ppmv in 1850 to 369.5 ppmv in 2000, for an increase of 81.5 ppmv, or 174 PgC. What makes things even worse is that this 174 PgC was spread out over the globe, whereas methane from such abrupt releases in the Arctic would - at least initially - be concentrated in a relatively small area.

Extension of methane's lifetime further amplifies its greenhouse effect, especially for releases that are two or three times as large as current releases.

The graph on the right, based on data by Isaksen et al. (2011), shows how methane's lifetime extends as more methane is released.

The GWP for methane typically includes indirect effects of tropospheric ozone production and stratospheric water vapor production. The study by Isaksen et al. shows (image below) that a scenario of 7 times current methane levels (image below,medium light colors) would correspond with a radiative forcing of 3.6 W/m-2


Such an increase in methane would thus add more than double the entire current net anthropogenic warming, effectively tripling the effect of all emissions added by people since the industrial revolution (for comparison, see the IPCC AR4 SPM and Wikipedia image below).


An addition of less than 30 Pg of methane could create such a scenario (i.e. of 7x the methane we're used to having in the atmosphere) and this would extend methane's lifetime to some 18 years, so such a burden will not go away quickly. The situation is even worse when releases take place abruptly over a short period. A single submarine landslide can release 5 Pg of methane, which can double the methane currently in the atmosphere when this occurs in shallow waters, since such a huge release will saturate the water, so most methane will enter the atmosphere unchanged, to trigger further releases.

7. Runaway Global Warming

This kind of warming in the Arctic could result in ever more methane ending up in the atmosphere and remaining there for a longer period without getting oxidized. Initially, all this methane will be concentrated in the arctic, causing huge amplification of the greenhouse effect there in summer, heating up the sea and causing further depletion of oxygen (as algae start to bloom) and further accelerating the permafrost melt and thus causing further carbon to be released from permafrost and clathrates.

Such dramatic local warming is bound to trigger further melting of permafrost locally, resulting in further releases of methane. Massive amounts of methane are stored in the Arctic, much of it concentrated at high density in hydrates. One liter of hydrate can release up to 164 liters of methane. A rise in temperature could cause abrupt releases of huge amounts of methane from hydrates.

8. What can be done about it?

Once runaway global warming starts, it feeds on itself. While dramatic reduction in global greenhouse gas emissions is imperative, that alone will not be able to stop runaway global warming.

Geoengineering methods could reflect some of the sunlight in the Arctic back into space, such as by distributing sulfur dioxide into the stratoshphere by jets, cannons or hoses, or by enhancing cloud albedo as proposed by Stephen Salter and John Latham (see image left).

Even halving the amount of sunlight may not be enough to reduce rapid warming in the region, if that would merely be like cutting methane's GWP in half. Moreover, it can take several years for warming to reach and penetrate hydrate sediments, as described by Nesbit, and once on its way, reducing surface temperature may not be able to reverse such a process quickly enough to avoid massive methane releases. In other words, the window of opportunity for solar reduction methods may already have closed.

Further methods include ways to ignite the methane using short, amplified and focused pulses of UV light from airplanes or satellites. UV light could also be used to produce more hydroxyl, in efforts to oxidize as much methane as possible.

Igniting or breaking down methane may also be possible using model airplanes, equipped with LiPo batteries and with solar thin film mounted both on top of and underneath the wings. Numerous such planes could navigate to the Arctic by autopilot in summer, when there are high concentrations of hydrogen peroxide and when the sun shines 24-hours a day. Flying figure-8 patterns with the wings under an angle could optimize capture of sunlight, keeping the planes in the air, while using surplus energy to power UV lights. Another methods could be to focus UV light on ozone and mix it with volatile hydrocarbons, in an effort to produce hydroxyls. At the end of summer, the planes could return home for a check-up and possible upgrade of the technology, to be launched again early summer the next year.

Such methods are further discussed at this geoengineering group.