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."
Re:rot (Score:5, Informative)
Methane is bad stuff (Score:4, Informative)
20 times better at trapping heat in the atmosphere. Warmer planet = more melting permafrost = more methane release = warmer planet.
http://www.epa.gov/methane/ [epa.gov]
Re:Weed need SIMPLE answers to questions... (Score:5, Informative)
(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.....
Yeah, the planet did fine, but it didn't support human life at the time. So, if human life is something you would like supported, then maybe there is a problem.
Some perspective (Score:5, Informative)
So I wondered just how much methane 2 mg/m^2/day is, and here's the breakdown:
2 mg/m^2/day times the area of the Arctic ocean (13,986,000 km^2) is 27,972,000 kg/day, or about 10.2 Tg/year.
10.2 Tg/year can be compared on this chart [wikipedia.org] to other sources. This is not an insignificant amount, but is an order of magnitude less than just the contribution from farm animals.
I'm not a climate scientist, and can't say what this may or may not mean for AGW, but it puts the size of the emission into perspective.
Re:positive feedback loop (Score:2, Informative)
Second derivative? You are just repeating what you have heard! The data is noisy. The second derivative is much noisier.
You are thinking of the first derivative. Have you even passed real calculus? (not the business/CS major version)
Re:Methane is bad stuff (Score:4, Informative)
"Methane is over 20 times more effective in trapping heat in the atmosphere than carbon dioxide (CO2) over a 100-year period" and "Methane (CH4) is a greenhouse gas that remains in the atmosphere for approximately 9-15 years".
Am I the only one who sees a huge logic flaw in that 100-year figure given the 9-15 year figure? How do the intelligent people here on Slashdot keep their bullshit meter from flying off the handle?
Imagine a retelling of Ach^W the Hare and the Tortoise. They decide to see who can run the furthest in 1 minute. At the off, the Hare sprints away but 10 seconds later he's completely exhausted and lies down to have a rest, having covered 100m in that time. Meanwhile, the tortoise plods along steadily and at the end of the minute....well, this is no fairy tale -- he's only managed 5 metres.
So, the Hare has covered 20 times the distance that the Tortoise has, even though he's only run for 10 seconds. No surprise, frankly.
Methane is actually about 70 times better as a greenhouse gas as CO2 in the short term, but we don't really care about the short term: long term effects are what are important. So, we can average it out over 100 years instead. Of course, methane doesn't just disappear when it breaks down; it ends up leaving CO2 in the atmosphere, so it has long term effects anyway. It's why, even though water is such a potent greenhouse gas, it doesn't matter as a temperature forcing mechanism because it drops out of the atmosphere within *days*. The amount the atmosphere can hold is dependant on the temperature.
However, what's bad about water, is that if something else causes the atmospheric temperature to rise, the overall effect won't just be from *that thing*. The warmer atmosphere will also hold more water which will cause an *additional* temperature rise.
Re:positive feedback loop (Score:5, Informative)
Dinosaurs lived at much higher temperatures.
They ate all the people back then though.
Re:Except... (Score:5, Informative)
I don't remember the exact details, but I thought it was like this:
If you cherry-pick the two years 1998 and 2008 (1998 being quite warm and 2008 a bit colder than the trend), and fit a line on the 10 temperatures from that particular 10 year period, then you can't say with 95% certainty that there's an upward trend, but only with less certainty IIRC. And they put Phil Jones on the spot "can you say with 95% certainty that it became warmer in that 10 year period?". So he had to say no.
I used the emotionally laden word cherry-pick because if you take another recent period of 10 years, or another period ending at 2008, or another period starting at 1998, then the upward trend is much clearer.
Please look at the graph: http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A2.gif .
Guess why the years 1998 and 2008 were taken. Get the data yourself (from NOAA or HadCRUT3), and plot it with something that can draw a linear regression line from the past 15 years that you mentioned (1996 to 2011) or just use a ruler and some common sense to draw a line through the points.
Then do the same for 1998 to 2008 (the cherry-picked data), and finally to see the famous "hockey-stick" one from 1898 to 2008.
Don't waste your time arguing why I'm wrong or stupid, just go download that data and draw it for yourself. I dare you.
Re:Ocean gun? (Score:5, Informative)
"According to the US National Snow and Ice Data Centre in Colorado, Arctic summer sea ice has increased by 409,000 square miles, or 26 per cent, since 2007 â" and even the most committed global warming activists do not dispute this." http://www.dailymail.co.uk/sciencetech/article-1242011/DAVID-ROSE-The-mini-ice-age-starts-here.html [dailymail.co.uk]
I'm afraid the Daily Mail was mistaken (it's a terrible paper; seriously, it's a celeb gossip rag -- don't quote from it). What the columnist was referring to was this [nsidc.org]
See in 2007 when there was a record low? The article you link to was written in 2010, so all they had was 2008 and 2009 data. See how those are both higher than 2007?
Now, those are the data that columnist is referring to. Look at it yourself. Do you think that it was honestly interpreted by the Daily Mail? Would *you* have presented those data as a trend of increasing ice?
Re:Ocean gun? (Score:1, Informative)
Again this is important because mammalian life thrived under those conditions. Therefore it would not be an extinction level event if CO2 levels were to again rise to those levels.
Re:Weed need SIMPLE answers to questions... (Score:3, Informative)
Re:Wait, wait, wait... (Score:2, Informative)
Whoa, hold on to your horses with your science oversimplification strawman. Sure we know all that about CO2, but we don't know what'll happen to it -- will it just sit there in the atmosphere? Will the changing climate affect how CO2 is released or absorbed by the oceans and the biosphere? Questions, questions, questions abound. Yes, surely a conservative approach is prudent, just in case everything was to go according to the direst predictions. Yet we can't claim it's anything more than willing to play it safe by default. We simply don't know any better.