A Methane Scenario

In reading recent posts about the methane “Arc tic time bomb” on the Neven Arctic blog (neven1.typepad.com), I realized that no one was developing a full-fledged scenario for how a serious methane emissions uptake from Arctic deposits could occur.  So here’s my (amateur) stab at it.

2007-2014

When, around 2007, the Northeast Passage opened up, few worried about the implications for methane emissions.  True, there were 50 Gt of methane locked up in methane clathrates (CH4 in a “water cage”), mostly under the shallow waters of the Arctic above Siberia, but it seemed there were several reasons not to worry:

• ·         Methane has a short half-life, unless it attains a concentration well above its concentration as of now;
• ·         It seemed then that even if the permafrost in which the clathrates resided melted, methane would only be released in a “bursty” manner by landslides caused by the loosening of the icy bonds of the underwater permafrosted land – certainly not in a steady stream such as would be needed to overcome the short half-life;
• ·         It also seemed that even if the methane was released from the clathrates, it would “pop” before reaching the surface, which in turn would mix more carbon with the water and hence put it in the atmosphere, or feed “blooms” which when they died each year would likewise release their carbon in the water and thence to the atmosphere – a fraction of the carbon already being emitted;
• ·         At present, the methane released (if any) was no more than a small fraction of the man-made amount of methane emissions – and that was still not near the danger point.

However, the warming water poured in from the North Atlantic along the western part of the Siberian Sea during the summer, and when Soviet researchers checked during the summer of 2012, methane bubbles hundreds of meters in diameter were coming up.  That meant that both the idea of “bursty” methane and the idea that all the methane would “pop” before reaching the surface were not accurate.  And yet, even during summer, the fluctuations detected amounted to less than 1% of methane emissions measured in the Arctic.  Clearly, some scientists argued, the other two factors (short half-life, small fraction of the total) meant that there was no immediate cause for concern.

And then el Nino arrived.

2015-2023

The splashier effects of el Nino distracted attention from its effects on methane emissions.  While it did indeed raise the temperatures down south significantly, its main effect was to warm the air in the Arctic (already in record-breaking territory) by 3 degrees in summer and by 10 degrees in winter.  The initial effect was to extend summer “insolation” (heating of ice and water from above) and above-freezing average air temperatures for 2 weeks on either end, so that the Arctic water was now just about completely ice-free and accumulating a “storage bank” of heat with which to melt the permafrost.

Now, the period of methane bubbles was lasting twice as long, and the pace of melting was four times as great.  Moreover, towards the end of the period, the small but steady warming of the Beafort Sea from the south was beginning to push into the eastern end of the seas above Siberia.  These, too, began to see bubbles and spikes in methane usage.

At the end of this period, another “distraction” arrived:  adjacent permafrost in Siberia began to thaw.  Although it was not clear in the beginning how much of that thaw would be methane and how much carbon, it turned out to be perhaps a 2/3-1/3 ratio.  Still, compared to human-caused methane emissions (which had gone up another 10% since 2007), the emissions from clathrates and the small contribution from Siberian permafrost were still much less.

2024-2032

Soon after 2025, la Nina arrived; but it had surprisingly little effect.  True, the ascent of temperatures in the Arctic slowed; but the warming water from previous years continued to pour into the Arctic.  That, in turn, extended the iceless Arctic period well into November, and the increasing energy in the air likewise extended the melting-out period over the Siberian seas into June.  And so, having quadrupled the last period, methane clathrate emissions tripled over this period, so that by 2033 worldwide methane emissions were up by 25% compared to 2007 – 15% from humans, 6% from methane clathrates, and 3% from land permafrost melt, which was undergoing its own steep climb.

Still, for a little while, the world could still file methane emissions in the Arctic under “lesser concerns”, at least compared to carbon emissions.  And there, as well, the contributions of carbon from permafrost were still minor compared to human emissions – not to mention the almost full effect of the decreased albedo of the Arctic.

2033-2040

These were the years when things got really serious.  El Nino returned, and the Arctic became ice-free year-round by around 2039.  The warm water year-round plus the increased insolation and the increased energy in the air year-round, transmitted to the water via storms, meant a quintupling of methane clathrate emissions – to a 30% increase over 2007.  Add on 10% from land permafrost and the 20% from human emissions, and methane emissions were up 60% -- an effect of much less than one degree F globally, but nonetheless significant.

And still the worst effects held off, until …

2041-2100

Methane clathrate emissions had reached somewhat of a “steady state”, in which melt reached progressively deeper into the permafrost, but the adjacent melted sediment continued to warm faster, as it penetrated to areas of greater pressure.  However, this “steady state” was adding about 50% more methane emissions than in 2007, at a steady pace.  Meanwhile, the permafrost contribution was steadily climbing, as melted permafrost converted to swamps which produced their own methane.  By about 2060, the result was a 100% increase in methane emissions in total – and that’s when the second shoe dropped.

Doubling methane emissions meant that the methane in the air was now saturated – it was far less likely to decompose into water and/or carbon dioxide.  As a result, the half-life of methane shot up, first to 20 years, and then to 40.  Now the other aspect of methane – that it is 70 times as powerful a greenhouse gas as carbon for the same half-life – began to come into play.  Effectively, the effect was 1 degree F of average global warming; but this was equivalent to the effect of the entire increase in carbon ppm in the atmosphere pre-2007.  To put it another way, methane added perhaps 33% to global warming up to 2070.

In the longer run, of course, carbon emissions continued to dominate for the next thousand years.  However, the land permafrost methane now assumed center stage, continuing the saturation for perhaps 300 of those years.  Global warming baked us; methane clathrates in the Arctic were the trigger to ensure that we were truly well done.

The Sad Implications of Two 2012 Climate Change Surprises

In reading postings in one of my favorite blogs recently (Neven’s superlative Arctic Sea Ice blog), it occurred to me that I hadn’t tried to summarize in my mind the two major surprises that scientists recognized in climate change last year.  What follows is my take on these surprises:

1.      Arctic methane is venting much faster than expected; and
2.        The weather effects of global warming are stronger than expected.

What are the implications?  Let’s take them one at a time.

Arctic Sea Ice and Methane

It still amazes me that most people did not see the likelihood that Arctic sea ice was going to take a nosedive to near zero in the 2013-2016 period, because I only had to apply some basic math when I first took a look in 2009:  exponential and normal curves.

Until recently, there was only one serious attempt to assess the volume of Arctic sea ice:  Maslowski’s PIOMAS model.  As I understand it, people tended to dismiss the model because Maslowski said:  this is the way I model Arctic sea ice dynamics, and therefore the sea ice volume should change over time in this and this way; and because he asserted without proof in his model that Arctic Ocean water temperature changes had a major role in increased melting over time.  However, when I saw that this model was constantly reality-tested by on-the-site sampling, even though each sample was of a small part of the overall Arctic Ocean, I realized that the long-term trends there were likely to be true.  And what Maslowski’s model showed, at any time of the year, was an exponentially decreasing Arctic sea ice volume.

By the way, recent Cryosat observations have definitively shown that, if anything, Maslowski’s model has underestimated the rate of volume decrease.

So why, I asked myself, do I not see corresponding decreases in Arctic sea ice area and extent?  As I looked at the dynamics of Arctic sea ice, I realized that that could only happen if there was a uniform distribution of Arctic sea ice thickness from, say, zero to twice the average thickness (at any time of year).  But what was really going on was that a certain percentage of the sea ice survived between years to become second year ice, third, and so on; but cue to currents, the average age of Arctic sea ice back in 1980 was five years – sooner or later, ice frozen at one end of the Arctic would reach the other end and head south into warmer waters, there to inevitably unfreeze.  Instead, thickness (with a little adjustment for the age of the ice) had much more of a normal distribution around the average. And that, in turn, meant that accelerated volume losses at, say, minimum would only show up in area and extent when we reached the fat part of the curve – which, it is now apparent, occurred in 2012.

By the way, the same logic also says that volume and the rest will not go to zero somewhere around 2014 – 2015; we will have reached the other thin end of the distribution, and the exponential decrease in volume will flatten out, exponentially.  That’s why I fully expect to see around 1-5% of the ice remaining at minimum until sometime around 2016-2020.

So, as I’ve said, I expected that Arctic sea ice would begin to obviously disappear around now, and I expected the climate change implications of this – including the fact that Russian-Arctic-Continental-shelf methane “clathrates” would begin to release their methane.  What I (and apparently others) did not expect was the scale of that release.  A Russian sampling of methane bubbling to the surface found huge pockets of the stuff – hundreds of times more than research had suggested might be the case.

Before I go on to discuss this, let me cycle back to the (expected) implications of Arctic sea ice melt.  Today’s models simply do not include melt to near zero at minimum in the 2013-16 time period, and a likely follow-on melt to near zero at all times of the year between 2035 and 2045. This in turn, will not directly lead to more carbon emissions.  What it will do is decrease Arctic Ocean albedo (from off-white-reflection to dark-blue-absorption of heat from the sun during the spring-summer-fall), and therefore warm up the Arctic Ocean portion of global and ocean temperature.  This already is 15-20 degrees Fahrenheit above normal during the summer; we are talking another 25-35 degrees by 2045, taking it to 20-25 degrees during the winter. 

The increased water and air temperature should therefore (a) accelerate methane clathrate melt, including that of the deeper waters nearer the North Pole, and (b) both cool and warm winter temperatures of more temperate zones – with the “warm” predominating over time.  How can (b) be?  Well, warmer Arctic air has more energy, and therefore pushes south against the “jet stream” more strongly, creating weather in which unusually cold Arctic air reaches further south periodically.  However, that same Arctic air is steadily warming over time, to the point where by 2050 it should be as warm as or warmer than southern winter air was in, say, 1980. 

Implications of the Methane Surprise

Part of the problem with assessing methane’s implications is that most if not all scientists have not factored in 2015-2045 Arctic sea ice melt’s implications for temperatures just a bit further south.  Because methane clathrate melt should be understood as part of a “double whammy” for methane – Arctic methane melt at the same time as permafrost melt.

Since (up to a point) methane has a very short half-life in the atmosphere (say, 8-10 years), you need a much greater rate of methane release into the atmosphere than carbon (all right, methane includes carbon too, but methane has a much greater effect on global warming per ppm than carbon dioxide) to achieve a comparable warming effect over time. And yet, studies of 55 million years ago, when the rate of warming was much less, indicates that methane had a major role in causing what Joe Romm at www.climateprogress.com calls “Hell and High Water”, with 90% of species wiped out.

Scientists have made a persuasive case for the idea that, even if methane clathrates are starting to melt and permafrost at the same time (i.e., even if we factor in Arctic sea ice melt), methane emissions will not reach a “danger point” where their effects in the atmosphere will rival that of carbon emissions any time soon – and therefore will avoid the main danger time of carbon emissions, before the lack of fossil-fuel reserves begins to decrease those emissions on its own). The problem is that the Russian observations indicate that those reassurances are based on assumptions about the rate of methane clathrate “bubble” occurrence that far underestimate their rate and/or amount.

So what, then, are the likely implications of this methane surprise?  As far as I can see, there are no “likely” implications, because the range of possible methane “bubble” rates, and therefore emission rates, over the next 40 years is so wide.   Nor is it clear to me, given that these emissions are occurring in such a localized northern area, just how wide an effect on global warming there will be.  However, my best guess is that over the next 40 years there will be a significant, localized effect:  Methane emissions will increase Russian and lower-Arctic-sea heat retention over what it would have been by perhaps 25%, with a corresponding increase in Arctic average temperature and Russian permafrost methane/carbon release.  This, in turn, may add perhaps ½ degree Celsius to global warming over the next 40 years – and, of course, will add a comparable amount over the 50 years following, at least – always remembering that a major fraction of methane released turns into carbon dioxide, and hangs around in the atmosphere for a hundred years or so on average.  In other words, the major effect of the surprise may be a more long-term one:  arrival of a ½ - 1 degree Celsius additional increase in “thousand-year” global warming now rather than later, when it would have less practical effect.   

The Weather Effect Surprise and Implications

Taking my cue from James Hansen and Joe Romm, I had guesstimated in 2009 that we in the US would first see constant, undeniable reminders that global warming is real in the 2020-2025 timeframe.  These reminders would include not only “hundred-year” hurricane-type wind speeds and scorching summers that created Dust-Bowl conditions in many areas, but also an overall burden of disasters that reached 0.1% of GDP even for a country like the US.  I believe it was Heidi Cullen that imagined NYC missing a massive hurricane in 2017 and getting one in 2041, by which time the city was prepared and the sewers did not back up and overflow, causing hundreds of thousands of deaths from disease.

But, as Joe Romm noted in his blog, the things that should have been expected in 2020-2025 seem to be happening in 2011-2012, ranging from devastating Australian rainstorms to stupendous Russian wildfires to Hurricane Sandy and its 13-foot storm surge (still short of the 20-odd-foot storm surge that might cause the sewer outlets to be closed and the sewers to back up, but enough to flood the subways and make downtown Manhattan, Queens, and Staten Island disaster areas).  It appears that the monetary effects of disasters globally, according to insurers like Munich Re, are 10 times what they were a decade ago, and there is no reason why they should not continue to double or triple by 10 years from now – meaning that the timetable for effects on global GDP should perhaps be moved up by 3-5 years.

The surprise is not that global warming is happening faster than predicted – globally, 2012 was actually about average for the last decade, which in turn means that it was one of the “dips” in our steady, accelerating global temperature ascent. The surprise is that the effects on weather were larger than expected.  What I suspect is that forecasts simply assumed that certain catastrophic events would happen more frequently than expected, but could not predict that these catastrophes would spread to areas where they had not before (devastating tornadoes in western Massachusetts), areas that were less adapted to a new set of weather patterns. We are reaching the point where we have not only extremes of existing weather patterns, but also new climates that produce new weather patterns.

And so, I also suspect that the effects of the “weather is changing faster than we expect” surprise are, like the methane surprise, bad but unpredictable.  I anticipate that the Nino/Nina cycle and North Atlantic Oscillation patterns that have driven weather around here since time immemorial (i.e., the last 5,000 years) are changing, but will manifest first in longer versions of the extremes of this cycle – and that’s a total guess.  Certainly, an extended Nino would mean even greater Dust Bowl conditions and summer heat over a great extent of the US for longer than ever before, even leaving out the effects of the ongoing global temperature warming.  Initial predictions show the US except the Northeast and Pennsylvania in catastrophic drought conditions in 2050 – is it possible it could happen before then?

Boy, I hope not. But, as a clueless Presidential candidate noted in 2008, hope is not a plan.

Conclusions

Overall, oddly enough, the implications of these surprises for me are not great.  I concluded in 2009 that we desperately needed to cut carbon emissions in absolute terms by 40% 2010-2020, and another 40% 2020-2030.  Since then, with extremely minor exceptions, all major countries in the world have utterly wasted their time in that regard.  In fact, my definition of functional insanity is to see oil companies and countries seeing Arctic sea ice melt as an opportunity for increased drilling of fossil-fuel carbon pollutants, and the United States seeing a Keystone XL pipeline that solidifies tar-sand drilling that sharply increases the likelihood of the end of all life on Earth as an opportunity worth considering, much less actually being relatively close to implementing it.

So, to my eyes, the horrible effects of the two 2012 surprises simply speed up what’s coming and increase its bad effects in relatively minor ways, and that will be worth it if people wake up now and start doing something globally effective.  Except that there’s little sign as yet that people and their leaders are even beginning to understand the urgency of an adequate scale of action.

I wonder what new surprises 2013 will bring?  I could really use some good news.

In Praise of neven1.typepad.com

Somewhere around two years ago, iirc, I happened on this blog. I had, as I remember, found it indirectly. I had been following Paul Krugman the economist for about 25 years, and saw in his NY Times blog a reference to Joe Romm’s blog on climate change.  Since I had recently been made aware by some public library books like A World Without Ice and Storms of My Grandchildren (Hansen), not to mention a summary of the IPCC 2007 report, of the importance of the subject, I followed Prof. Krugman’s pointer to www.climateprogress.com. There I happily followed Mr. Romm’s pointers to in-depth recent research and other ways to sharpen my understanding of the subject.  And then he pointed me to a blog on Arctic Sea Ice – neven1.typepad.com.

It has been an extraordinary two years of reading, and a very rewarding journey. I must therefore give full credit up front to its presiding spirit, Neven – of whom I confess I know very little, aside from the facts that he is Dutch and that he apparently at one point considered trying to find a retirement place in Tasmania.

What has made my time following this blog so very rewarding, aside from the importance and urgency of the subject matter – about which I have written many times before, and will, I’m sure, again – is the sheer richness and variety of the accessible information available to the patient lurker. This was not fully apparent at the start. Indeed, my memory of my first impressions was that this was a site trying to piggyback off not very available scientific data on trends in Arctic sea ice, and having to fend off “climate denialists” attempted to clutter up the comments at the same time.

“Denialists” were, of course, yet another variant on the garden-variety “troll” that I had first seen in 1981 with my first experience of the Internet and newsgroups. As had been increasingly happening since the late 1990s, they made up in pack mentality and corporate encouragement for their decreasing skills in swearing and logic. Nevertheless, they posed a danger to all decent blogs:  that the “moderator”/blog poster would become so taken up with warring with denialists that their great value in conveying new information outside the traditional structures of academia and the like would be completely diluted – something that concerns me about Climate Central to this day.

However, over the last two years, I find that I have gotten as much if not more solid scientific background from neven1.typepad.com on certain subjects than even www.climateprogress.com.  Consider the following:

• ·         The early/final stages of sea ice freezing/melt, which can deceive instruments and therefore forecasts, but which we have learned to adjust for – melt ponds and the like.
• ·         The strange case in which global warming can decrease Antarctic land ice and yet initially increase Antarctic sea ice (by about 1% per decade).
• ·         The role of wind and current in propelling any individual chunk of Arctic sea ice across the top of the world, to eventually melt in the northern Atlantic.
• ·         The role of insolation and changed albedo, not just in speeding existing ice melt but also in having follow-on effects on world climate.
• ·         The effect of Arctic sea ice melt on Greenland land ice melt rates, not to mention the speedup in both from added global warming in the summer in the north.
• ·         The effects of warmer water currents as opposed to warmer air temperatures in speeding melt.
• ·         The alarming role of methane, of which Arctic may be as much as a sixth of the sources of this greenhouse gas in the next century.

All this plus the mixed joy of watching a terrible but fascinating race, in which I at the same time guess a certain minimum area, extent, and volume of Arctic sea ice for a year, and “root” for the correctness of my guess, and still dread the possibility that I will continue to be more or less right – which would mean that most even of the concerned and reasonable are underestimating the speed with which disaster is approaching.  After all, we still hear forecasts of 2100 for less than 5% Arctic sea ice cover at minimum, or 2045, or 2030, but the Maslowski projection of 2013-2016 (which I think translates to 2016-2020) is still rarely espoused – and that’s what I predict and fear.

Back in 2010, as I recall, everyone was hung up on extent statistics, because area was less volatile and volume measurements were distrusted (wrongly, I believe). And so, we got our daily fix by betting on extent minima and neven1.typepad.com pretty much closed up during the winter, with cute pictures of polar bears and other hibernating creatures. Today, there is an extraordinary wealth of graphs to look at, about extent, area, volume, thickness, and their trends, as well as the climate equivalent of “radar”: pictures of daily ice concentrations. I don’t know what this winter will bring, but last winter was quite busy, what with methane, discussions of trends in sea ice maxima, and discussions of shifts in weather patterns in North America and North Eurasia due to changes in the North Atlantic dipole anomaly. Somehow, I think the blog will find it hard to hibernate this year as well.

Because it is apparent even now, more than a month from any minima, that this year is a continuation of the trend, and it is going to be bad. There’s perhaps a 5% chance that there won’t be a new area minimum, to accompany yet another new volume minimum and a likely possible extent minimum. The “radar”, for the first time, is showing bits and pieces of ice rather than dense concentrations, closer and closer to the Pole, and the thickness projections for 5 days from now are for very thin ice within 3 degrees of the Pole. So now, the question will be, how long into October will the Arctic waters hold the warmth of the summer sun beating down on open water until sometime in September? As we enter a new normal of longer and longer periods of ice-free Arctic waters, how long will the gloom of night and lower temperatures in Arctic winter stave off the prospect of an ice-free Arctic year-round, not only increasing global temperatures from lower albedo but also possibly unlocking more stores of methane?

And the last month has seen an extraordinary series of blog posts by Neven and comments by perennial commenters to enhance the understanding and richness of Arctic (and Greenland) ice analysis – to the point where Neven is almost becoming a fixture on www.climateprogress.com.

And so, I recommend to the two or three people who actually read this blog the guilty pleasure (?) of reading neven1.typepad.com for your daily fix of extent and area figures, and for the extraordinary bursts of mixed opinion and analysis that follow. As with every blog, in the comments there are gems and there is manure; but the proportion of gems lately is quite high, imho. And no, I haven’t said anything for weeks; what need?

I reluctantly followed a link to Anthony Watts’ denialist site today, and was struck by an amazing realization:  it wasn’t just that they were living in another world, it was a much poorer world.  There was no discussion of melt ponds, or possible cyclones that might break up the ice and melt it further; in fact, there was nothing, except general discussion by people obviously not that interested in learning more about just how things worked.  To misquote George Bernard Shaw in Man and Superman, it wasn’t  just that they were wrong, it was that they were extraordinarily uninteresting.

And then there’s neven1.typepad.com. Here’s to another two wonderful and terrible years. And thanks. Thanks for so much.