October 20, 2014
UPDATE: a reader sends a link to a more recent (june 2014) Shakhova interview. The sound quality not as good, which makes it difficult to follow, nevertheless,I am posting this in the interest of furthering the discussion. This is a “part 1″ of 3, the others being available at the you tube link.
In the past week, I’ve been posting a number of excerpted interviews relating to the topic of undersea methane releases in the arctic.
This has not actually been something I planned out just this way. The idea was, I wanted to interview as many folks behind the scenes and find out as much as I could, then synthesize everything into a nice tidy video, and release that. But events have kind of overtaken that.
In September, the Royal Society held an event in the UK which drew a number of experts on arctic ice and the rapid changes observed there. Among those was Dr. Gavin Schmidt, of NASA, one of the most highly respected experts on the planet in areas of global climate. Dr. Schmidt gave a well attended lecture on the issue of arctic methane, specifically to push back against what has become somewhat of a Youtube cottage industry, methane disaster porn. It’s not hard to find material proclaiming the imminent extinction of humanity due to the massive release of methane from arctic ocean shelves – and I agree with Dr. Schmidt that this kind of material is irresponsible and divorced from reality.
The scientific source often cited (and then, I think, exaggerated) for such dire pronouncements is the work of Dr. Natalia Shakhova, the University of Alaska in Fairbanks, and her associate Dr. Igor Semilitov. Short story, Shakhova et al were not at the UK shindig, leading to charges of conspiracy to exclude them from the discussion. Since I started this series, I’ve even been getting emails darkly hinting that perhaps I was a tool of that conspiracy, as well. I don’t think a preference to step carefully is indicative of a conspiracy, but never mind.
Among Dr. Schmidt’s strongest arguments are datasets that he says indicate little or no methane breakout in the relatively near paleo-record, from 2 previous eras.
First, the Holocene warm period, – at about the time the planet was coming out of the last ice age, the arctic was warm, possibly warmer than today, forna period substantially longer than the current warmup. The other period, known as the Eemian, was an interglacial, a temperate spell, like ours, just before the plunge in to the most recent ice age, about 120,000 or so years ago. We know it was pretty warm for quite a while – thousands of years – because sea level was high - maybe 15, or 20 feet higher, and a substantial portion of the Greenland ice sheet seems to have melted.
Yet, Schmidt says, we saw no methane breakout.
This paleo argument is compelling to me, as I have always considered the fossil record a powerful indicator of how the current climate will behave.
Could we have more of a buffer for big methane belches than we know? Here are two slides from Schmidt’s lecture – which is not available to my knowledge online, although may be soon, at least in audio.
There’s a lot more material on this, much of which I have not digested myself, but I wanted to get as much of this under-seen and under-discussed material online where people can read it, and spark a tiny bit more informed discussion on the issue, something I am sure Dr. Schmidt, Dr. Shakhova, and all concerned, would like to see happen. There are a lot more perspectives on this than what most people have heard, so now is as good a time as any to hear them.
Clearly this is an important discussion, and more information is needed. Happy to hear from anyone who has additional useful resources on this issue, and ideas about how to broaden the discussion.
Methane from the Siberian continental shelf
The Siberian continental shelf is huge, comprising about 20% of the global area of continental shelf. Sea level dropped during the last glacial maximum, but there was no ice sheet in Siberia, so the surface was exposed to the really cold atmosphere, and the ground froze to a depth of ~1.5 km. When sea level rose, the permafrost layer came under attack by the relatively warm ocean water. The submerged permafrost has been melting for millennia, but warming of the waters on the continental shelf could accelerate the melting. In equilibrium there should be no permafrost underneath the ocean, because the ocean is unfrozen, and the sediment gets warmer with depth below that (the geothermal temperature gradient).
Ingredients of Shakhova et al (2013)
- There are lots of bubbles containing mostly methane coming up from the shallow sea floor in the East Siberian Arctic shelf. Bubbles like this have been seen elsewhere, off Spitzbergen for example (Shakhova et al (2013)). Most of the seep sites in the Siberian margin are relatively low flow but a few of them are much larger.
- The bubbles mostly dissolve in the water column, but when the methane flux gets really high the bubbles rise faster and reach the atmosphere better. When methane dissolves in the water column, some of it escapes to the atmosphere by evaporation before it gets oxidized to CO2. Storms seem to pull methane out of the water column, enhancing what oceanographers call “gas exchange” by making waves with whitecaps. Melting sea ice will also increase methane escape to the atmosphere by gas exchange. However, the concentration of methane in the water column is low enough that even with storms the gas exchange flux seems like it must be negligible compared with the bubble flux. In their calculation of the methane flux to the atmosphere, Shakhova et al focused on bubbles.
- Sediments that got flooded by rising sea level thousands of years ago are warmer than sediments still exposed to the colder atmosphere, down to a depth of ~50 meters. This information is not directly applied to the question of incremental melting by warming waters in the short-term future.
- The study derives an estimate of a total methane emission rate from the East Siberian Arctic shelf area based on the statistics of a very large number of observed bubble seeps.
October 19, 2014
I met Rick Piltz in DC several years ago. He had been doing yeoman’s work on climate issues for a long time already, including blowing the whistle on underhanded attempts to quash scientific inquiry.
I was saddened to hear last night that he had passed away.
Rick Piltz, the man who blew the whistle on the George W. Bush administration’s vicious assault on climate science, has passed away.
From Climate Science Watch:
From 1995-2005 he held senior positions in the Coordination Office of the U.S. Global Change Research Program. In the spring of 2005, Rick resigned from his position to protest the Bush Administration’s political interference with climate change communication. His whistleblower documentation of politically motivated White House editing and censorship of climate science program reports intended for the public and Congress received front-page coverage in the New York Times and was widely reported in the media. Rick testified before both the House of Representatives and the Senate at hearings on political interference with federal climate scientists.
Piltz was, of course, brutalized by the climate-change denial industry for his bold decision to reveal the full extent of the Bush administration’s malevolence on this issue: the late wingnut columnist Robert Novak was particularly savage in his attacks.
Piltz refused to bow down to the forces of denial. After leaving the Bush White House, he continued to speak and write and fight for strong action to reduce carbon pollution, and demanded that members of both parties be held accountable for failing to take all appropriate and necessary action to limit dangerous emissions.
Rick Piltz may be gone, but his fight continues. We will fight in his name, and we will make sure that his name is remembered as a hero in the fight for climate justice.
Along with Dr. Jim Byrne, and Geoff Haines Stiles, I interviewed Dr. Richard Alley, along with 22 other leading scientists at last year’s American Geophysical Union Fall Meeting.
Dr. Alley had just finished work as part of a National Academy of Science project on Abrupt Impacts of Climate Change – a useful and authoritative look at potential unforeseen and sudden impacts, including the possible release of methane from ocean shelves. Below is most of the section on that issue, and Dr. Alley gives a 5 minute non-technical synopsis above.
Takeaway, potential problem, most likely on century or milennial time scales, but can’t rule out surprises.
My goal in this series is to make available some of the key documents on this issue, so that, first of all, I get the chance to evaluate them myself – but also for other folks to be able to follow the threads. There will be more this weekend.
Below, the section of the report mentioned above, dealing with undersea methane.
Potential response to a warming climate Climate change has the potential to impact
ocean methane hydrate deposits through changes in ocean water temperature near
the sea bed, or variations in pressure associated with changing sea level. Of the two,
temperature changes are thought to be most important, both during the last deglaciation
(Mienert et al., 2005) and also in the future. Warming bottom waters in deeper
parts of the ocean, where surface sediment is much colder than freezing and the hydrate
stability zone is relatively thick, would not thaw hydrates near the sediment surface,
but downward heat diffusion into the sediment column would thin the stability
zone from below, causing basal hydrates to decompose, releasing gaseous methane.
The time scale for this mechanism of hydrate thawing is on the order of centuries to
millennia, limited by the rate of anthropogenic heat diffusion into the deep ocean and
sediment column. Even on the Siberian continental margin, where water temperatures
are colder than the global average, and where the sediment column retains the cold
imprint from its exposure to the atmosphere during the last glacial time 20,000 years
ago, any methane hydrate must be buried under at least 200 m of water or sediment.
Bottom waters at depths of 50 or 100 m might warm relatively quickly with a collapse
in sea ice cover, but it would take centuries for that heat to diffuse through the 100-
150 m of sediment column to the hydrate stability zone. Thus the release of 50 Gt C
from the Siberian continental shelf in 10 years as postulated by Whiteman et al. (2013)
is unlikely. Read the rest of this entry »
October 17, 2014
Terrorists. Oil revenue.
Ebola. Cruise Ship.
A new study, published Thursday in the journal Science, is the latest to indicate that tornadoes have been acting differently lately. NOAA researchers looked at U.S. storms going back to 1954, and found that the number of “tornado days” (days during which a tornado occurs) has declined since the 1970s. Since the total number is remaining steady, that means that tornado days are rarer but also more eventful. In 2011, for example, there were only 110 tornado days, down from the 1970s average of 150 — but nine of those days saw more than 30 tornados each. One horrific two-day stretch saw 175 confirmed twisters.
The study also finds that tornado season has been occurring erratically: while the heaviest activity usually begins in March and April, things are now getting started both extremely early or extremely late, depending on the year.
The changes have practical implications, as insurers and emergency responders need to anticipate less frequent, but potentially more damaging, tornado disasters. As Harold Brooks, the study’s lead author, told Science magazine, “We need more resources … even if we don’t use them very often.”
The money question, of course, is whether or not this is our fault. The atmosphere has certainly been changing since the 1970s, warming as a result of greenhouse gas pollution. But while the researchers don’t think the changes they observed stem from a reporting problem, they say it’s too soon to draw a link between climate change and tornadoes gone wild. “We know that tornadoes form when there is lots of energy available for thunderstorms and when there is lots of wind shear,” Brooks told Smithsonian Mag, noting that while the former is increased by global warming (heat = energy), the latter is expected to decrease.
Brooks’ team logged an increase of as much as six times in days with multiple tornadoes. In the ’60s and ’70s, there was 0.5 to one day each year with more than 30 tornadoes ranking above EF-1; in the past decade, that number has shot up to three days. The last year to feature less than two days with under 30 twisters was way back in 2002. Here’s more from the study:
In effect, there is a lower probability of a day having a tornado, but if a day does have a tornado, there is a much higher chance of having many tornadoes. As a result, tornadoes are “concentrated” into a smaller number of days in more recent years. Approximately 20 percent of the annual tornadoes in the most recent decade have occurred on the three “biggest” days of each year, in contrast to 10 percent in the earlier period. This concentration leads to the potential for short periods of time, such as months, to have extreme (both large and small) numbers of tornadoes.
October 17, 2014
October 16, 2014
I’ve been talking about the revolution in transportation for some time, and one of the classic responses I get when I bring up electric cars is, “But wait, cars are the problem, we need to get away from cars.”
Typically this will be in a setting where almost everyone has arrived and will leave in a car. Not the best idea, this total American reliance on the automobile, but it is, for now, a fact. I point out that even if we plunge into an Apollo scale program to bring US mass transit up to the standards of, say, Europe – that’s a 30 year program, and at the end of it, we’re still going to have lot of cars – and we should be thinking about changing the way we fuel them. That said, I’m all about mass transit, and increasingly, cities around the country are getting it, and realize that if they want to be successful and vibrant, good public transit is a priority. Even Detroit is now breaking ground on a new light rail system. I’ll be reporting more on this in the future.
It’s fascinating that, when I did my previous video about electric car solutions, one of the main points I was making was the idea of “V to G”, vehicle to grid storage of energy – which is still a good, viable idea – but the interesting addition to the mix now is the rapidly exploding revolution in solar technology, and right behind that, battery tech. Just a few years ago, the idea was that the only batteries large enough to store significant energy would have to be in a car, they’d be too expensive to be part of a household system. Now, better technology, and equally important, new economic models, are going to make household energy storage systems much more common, even ubiquitous.
So the idea, expressed in the video, of “driving on pure sunlight” – seems much more within reach than it did just a few years ago.
For reference, here’s my older video, obviously dated because it came out before the Chevy Volt, but still useful. Read the rest of this entry »
October 16, 2014
Here’s another except from my conversation with Dr. Carolyn Ruppel, Chair of the US Geological Survey’s project on gas hydrates – ie, the so-called “Methane Bomb” issue.
I will be posting more interviews on this issue in coming days.