Massive Methane Release In the Arctic Region 264
Taco Cowboy writes "Arctic methane release is a well recorded phenomenon. Methane stored in both permafrost (which is melting) and methane hydrates (methane trapped in marine reservoirs) are vulnerable to being released into the atmosphere as the planet warms. However, researchers who are trying to map atmospheric greenhouse gas concentrations on a global basis have discovered that the amount of methane emissions in the Arctic region do not total up. Further research revealed that significant amounts of methane releases came from the Arctic ocean (abstract) — as much as 2 milligrams of the gas is released per square meter of ocean, each day — presumably by marine bacteria surviving in low-nutrient environments."
Ocean gun? (Score:5, Interesting)
People have been concerned about the possibility of a Clathrate gun for a while. Is this another potentially lethal feedback loop?
And if it fires, or has already fired, will we notice immediately?
Re:positive feedback loop (Score:5, Interesting)
Its pretty much too late to do anything useful. There are some way out there schemes but the most positive effect for species survival now is figuring out how to sustain our population on a warming Earth. We're going to have to get used to more extreme weather limits and redo our calculations and weather models for starters.
I suspect that cephalopods are about to be in for a pretty wild ride. As the ocean acidifies, shell fish will have less and less protection as the calcium carbonate that makes up the bulk of their shells gets dissolved more rapidly than they can replace it. This may lead to a population boom which will be quickly turn in to a starvation scenario.
If this happens, large marine predatory fish will go through a smaller version of this, which could be followed by the replacement of these fish in their niche by large predatory cephalopods. (most likely the D. gigas or A. dux)
Of course, that's just a guess. Everything in the ocean that relies on calcium carbonate is in for a rough time. This includes fish teeth and cephalopod beaks.
Another whammy is that as the ocean acidifies, the calcium carbonate reacts with the acid to form calcium bicarbonate and carbon dioxide, further increasing the saturation of the surrounding water resulting in a lower pH and a more intense feedback loop.
Re:positive feedback loop (Score:1, Interesting)
Shhh. It's hard enough to get deniers(I hate that term, is there an less biased term that doesn't give them undue credibility like "skeptic" does)
'False skeptic' is an accurate term for many deniers. They claim to be skeptical, but aren't willing to look at all the evidence as a true skeptic would do. Instead many strategically (or subconsciously) select the bit's and pieces that serve their goal of undermining the larger body of evidence for anthropogenic climate change. A true skeptic is open to being convinced by the evidence.
Parent post:
Re:Methane Trapped in Ice (Score:4, Interesting)
Good news: We're still in the middle of an ice age. It's not as hot now as it was 2.5 million years ago (when there was no ice on the poles).
Re:Methane Trapped in Ice (Score:4, Interesting)
That's great. Now we just have to adjust our civilization to work the same as that other advanced civilization that existed 2.5 million years ago, and we're all set.
--Jeremy
Re:We need SIMPLE answers to questions... (Score:5, Interesting)
gregmark mused:
(o) So those trapped gases must have been in the air at some point, millions of years ago, and then planet did just fine. So what's there to worry about? Uh.....
The carbon component of "those trapped gases" (i.e. - methane) may well have been "in the air" at some point in the past - but likely not as part of a methane molecule. Methane is a gas mainly produced by the decomposition of organic material. When the last ice age descended (most likely because of a meteorite or cometary impact event), it swiftly buried boreal forests in ice, and Arctic temperatures have kept the ground that they're now buried under frozen solid (which is why it's called "permafrost"). As the temperature warms, and that permafrost thaws, the decay process that the ice suspended will restart, and cause the dead and buried plant life to rot, producing very large quantities of methane gas from the carbon that used to be part of that plant life.
As for how methane clathrates (the other very large source of methane gas releases) are formed, I have yet to see a convincing explanation of the mechanism. That notwithstanding, the fact that they DO exist is indisputable - and, when deepwater temperatures rise far enough, they definitely will melt, releasing their cargo of methane into the atmosphere (the so-called "methane clathrate gun" effect) more-or-less all at once.
The current consensus is that it was the global release of large volumes of methane in the transition from the Permian to the Triassic Periods that caused the extremely large (20+ degrees Fahrenheit) increase in global temperatures that resulted in what is known as the Permian Extinction - an event that resulted in the extinction of more than 90% of all then-extant species on Earth. What is particularly scary about that event - the worst mass extinction since the Oxygen Catastrophe - is that the release of all that methane seems to have been initiated by a sharp increase in atmospheric carbon dioxide. In the Permian, that surge of CO2 was caused by a huge, long-lasting basalt flow event (a kind of large-scale volcanic eruption) called the Siberian Traps.
Today, however, the increase in atmospheric CO2 is largely manmade. Regardless of its source, the marginal warming effect of all that CO2 our electric power generation, heating, combustion engine-based transportation, and large-scale deforestation is producing will, without question, eventually result in a massive methane release, just as happened in the Permian. Our atmospheric CO2 levels are already very close to those that triggered the methane releases that resulted in the Permain Extinction, and there's no technolgy currently in existence that will allow us to "scrub" that CO2 out of our atmosphere. That, in turn, means that we're pretty much stuck with a future in which the planet warms suffiiciently to melt the polar and Greenland icecaps - and all the world's glaciers, as well - and release the methane clathrate deposits, too. How long this will take is the main unanswered question, now. The international consensus is that it will be on the order of a millenium before the planetary warming process reaches its peak, but there's some reason to believe that the icecaps are what used to be known as "chaotic systems" (i.e. - systems whose existing state is highly unstable, and subject to very rapid change if the conditions under which they are maintained change in relatively modest ways), and, if so, the collapse of the world's ice sheets could happen in as little as a century or so.
This is the problem with the plea for "simple answers". The systems we're talking about aren't simple - they're vast, complex, and (by the timescale of a single human life) slow-moving. The time to get out ahead of global warming was the 1970's. It's far too late now to prevent the planet from warming enough to melt the icecaps and change the climate sufficiently to result in another mass extinction event. At this point, we can only try to slow the process down, not stop
Rain Forest (Score:5, Interesting)