a 1 Gt burp
Jan. 29th, 2012 11:13 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
ljgeoffThis morning I dreamed about a great and sudden change. As I've said, I've been fretful lately. A large part of this is that the setbacks that I've experienced this year have also set back my long term plans, and that has my back brain going.
I have been reading a lot about the changes that are accelerating in the arctic. Because of some unusual readings, a couple of Russian scientist where able to convince whomever they needed to convince to give them some funds to go take a look. Natalia Shakhova and Igor Semiletov have been studying methane release in the arctic for the last twenty years or so. It is their lives' work. These people are not out for fame or fortune; they are not radical in any way.
They are funny in the way that I tend to think all scientists are. They look at the arctic from a long view -- a geological view. And they think that the changes that we are seeing now are very exciting. What an exciting time to live in, to see change that the earth has rarely seen! It is too bad about all the people, though.
Yesterday, Tenny Naumer over at Climate Change wrote that enormous leads were forming in the arctic ice. About some January 2012 arctic ice satellite images, she wrote:
"I've been looking at these images for about 4 years now, and never have I seen anything even closely comparable to the current state of the ice in the dead of winter when the ice should be growing and becoming more tightly knitted."
Not very many science writers are talking about what will happen when the arctic ice cap disappears. That's because no one really knows, and though quite a few scientists have opinions on what will likely happen, it is anathema for scientists to speculate in public. Which makes Natalia Shakhova's speculation - that the abrupt release of up to 50 Gt methane is highly possible at any time - particularly startling.
In the Arctic News Blog, science blogger and climate activist Sam Carana writes:
"Using the IPCC figures, applying a GWP of 72 times carbon dioxide would give 1 Gt of methane a greenhouse effect equivalent to 72 Pg of carbon dioxide over 20 years. Applying a GWP of 105 times carbon dioxide would give 1 Gt of methane a greenhouse effect equivalent to 105 Pg of carbon dioxide over 20 years.
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 Pg C. (14)
Note that this 174 Pg C was released over a period of 150 years, allowing sinks time to absorb part of the burden. Note also that, as emissions continue to rise, some sinks may turn into net emitters, if they haven't already done so."
I don't know enough about the science to know if Sam's figures are correct, but it jibes with everything else I've been reading. If his figures are right, then a 1 Gt release of methane would have the same warming effect over the first 20 years or so as increasing CO2 by about 50 ppmv.
Since the anthropomorphic release is currently about 2 ppmv/year, that would be like 25 years of business as usual, all at once. And that's just a 1 Gt burp.
It's kindof like worrying about an asteroid strike. Except it's not. Because this is something that has a very high chance of happening, and the warmer the arctic gets, the more likely it is that this will happen.
I have been reading a lot about the changes that are accelerating in the arctic. Because of some unusual readings, a couple of Russian scientist where able to convince whomever they needed to convince to give them some funds to go take a look. Natalia Shakhova and Igor Semiletov have been studying methane release in the arctic for the last twenty years or so. It is their lives' work. These people are not out for fame or fortune; they are not radical in any way.
They are funny in the way that I tend to think all scientists are. They look at the arctic from a long view -- a geological view. And they think that the changes that we are seeing now are very exciting. What an exciting time to live in, to see change that the earth has rarely seen! It is too bad about all the people, though.
Yesterday, Tenny Naumer over at Climate Change wrote that enormous leads were forming in the arctic ice. About some January 2012 arctic ice satellite images, she wrote:
"I've been looking at these images for about 4 years now, and never have I seen anything even closely comparable to the current state of the ice in the dead of winter when the ice should be growing and becoming more tightly knitted."
Not very many science writers are talking about what will happen when the arctic ice cap disappears. That's because no one really knows, and though quite a few scientists have opinions on what will likely happen, it is anathema for scientists to speculate in public. Which makes Natalia Shakhova's speculation - that the abrupt release of up to 50 Gt methane is highly possible at any time - particularly startling.
In the Arctic News Blog, science blogger and climate activist Sam Carana writes:
"Using the IPCC figures, applying a GWP of 72 times carbon dioxide would give 1 Gt of methane a greenhouse effect equivalent to 72 Pg of carbon dioxide over 20 years. Applying a GWP of 105 times carbon dioxide would give 1 Gt of methane a greenhouse effect equivalent to 105 Pg of carbon dioxide over 20 years.
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 Pg C. (14)
Note that this 174 Pg C was released over a period of 150 years, allowing sinks time to absorb part of the burden. Note also that, as emissions continue to rise, some sinks may turn into net emitters, if they haven't already done so."
I don't know enough about the science to know if Sam's figures are correct, but it jibes with everything else I've been reading. If his figures are right, then a 1 Gt release of methane would have the same warming effect over the first 20 years or so as increasing CO2 by about 50 ppmv.
Since the anthropomorphic release is currently about 2 ppmv/year, that would be like 25 years of business as usual, all at once. And that's just a 1 Gt burp.
It's kindof like worrying about an asteroid strike. Except it's not. Because this is something that has a very high chance of happening, and the warmer the arctic gets, the more likely it is that this will happen.