The Weekly Carboholic: Jet stream drift may confirm global heating models

Posted on April 23, 2008

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carboholic

The jet stream has been described by many as a river of air in the atmosphere. It’s similar in that respect to the Gulf Stream in the ocean, and both serve similar climate functions – the distribution of hot air (or water) from the tropics toward the poles. In the case of the jet stream, however, it also moves around high and low pressure systems and is thus one of the more significant controls over global weather. So when something happens to the jet stream, it matters. And according to MSNBC, a paper from the Carnegie Institution shows that the jet streams in both the northern and southern hemispheres have been migrating toward their respective poles.

This is noteworthy because it parallels one of the expected results out of various global climate models – as the Earth heats up, the tropics expand poleward and push the jet streams further toward their respective poles. Now, the authors of the paper have been careful to say that they cannot prove that global heating is the cause of the observed migration since the early 1970s. Correlation doesn’t prove causation, after all, and it will take a great deal more modeling, data interpretation, etc. to prove causation. But the correlation is certainly suspicious.

12.5 miles per decade is how fast the jet stream over the United States has moved northward. It doesn’t sound like much, but the author of the study, Ken Caldeira, said for the MSNBC story “that works out to about 18 feet per day. If you think about climate zones shifting northward at this rate, you can imagine squirrels keeping up. But what are oak trees going to do?”

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According to the Spiegel Online, Russian scientists are presenting research that submarine permafrost deposits off the Siberian coast are very close to melting. These deposits contain very high amounts of methane in the form of methane hydrates. This form of methane is frozen in water ice, and if the permafrost containing the methane hydrates melts, the methane will be released in the atmosphere. Since methane is a greenhouse gas and it’s 20x more powerful than carbon dioxide, having melting submarine permafrost release large amounts of methane into the atmosphere would be very bad.

According to the Spiegel story, the Arctic continental shelf within 200 m of the ocean surface contains an estimated 540 billion tons of methane. For comparison, the UN Climate Change 2001 report estimated the total extra methane released by nature sources to be 270 billion tons of methane per year, of which only 10 billion tons were from methane hydrates. However, the Russian scientists measured dramatically higher methane concentrations in both the ocean and the air over the hydrates:

The seawater proved to be “highly oversaturated with solute methane,” reports [Russian biogeochemist Natalia] Shakhova. In the air over the sea, greenhouse-gas content was measured in some places at five times normal values. “In helicopter flights over the delta of the Lena River, higher methane concentrations have been measured at altitudes as high as 1,800 meters,” she says.

“Normal” for the atmosphere is about 1,700 parts per billion (ppb) global average, while “normal” for the last 650,000 years has ranged naturally between 450 and 700 ppb.

Methane stored in oceanic hydrates is suspected as having been involved in at least two mass extinction events, specifically the Permian-Triassic (P-T) mass extinction and the end Paleocene extinction. However, the cause of these releases is not currently known. However, the P-T extinction is believed to have only involved 20% of all the hydrates being converted into atmospheric methane, or 2 trillion tons – only 4x the amount of methane estimated to be in the Arctic hydrate deposits.

Methane hydrate is being considered as a potential future source of natural gas, and it may well be that we can convert these massive reserves of methane into usable fuel to displace coal as a short-term solution to some of the world’s energy needs. But burning methane is hardly a solution to our energy and global heating problems, and given the sheer quantity of methane locked up in hydrates around the world, we couldn’t possibly burn enough of it fast enough to prevent some of the methane doomsday scenarios. Even if we could, we’d just be dumping that much extra carbon dioxide into the air instead, and that’s the biggest part of the global heating problem already.

What this does tell us, though, is that we need to understand the science of methane hydrates better than we do at present. As Shakhova says at the end of the Speigel story, “this is a wake-up call for science.”

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I got a press release this last week about a new website, GreenYour.com. The premise of this site (which is still in beta, FYI) is that you should be able to find everything you need about making your life more green. Let’s say you want to find out about green insect repellents. You can either enter “bug spray” into the search box and then select “insect repellent” from the search results, or you can drag your mouse over the categories to “personal care” and then down the list to “insect repellents”. Once there, though, you have three tabs to choose from – facts, tips, and products. “Facts” talks about DEET and permethrin personal insecticide (for clothing) as well as problems with both, when and where you shouldn’t wear either (going swimming, for example), disposal of used cans of repellent, health issues, even controversies and links to external resources about chemical repellents. “Tips” gives you nine ways to “green” your bug repellent, starting with “don’t work outside when bugs are most active”, proceeding through “use nontoxic natural bug sprays” and “introduce beneficial predators to keep pests away” and ending with “buy DEET repellent products in bulk to cut down on plastic packaging” (some paraphrasing was used). And as you can probably imagine, “Products” are just that – a list of products, conveniently organized by the Tip they relate to, you can purchase to “green” your insect repellent.

It’s too early to say if this is going to be the green site that it hopes to become. But it certainly has potential.

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Renewable energy or unspoiled natural landscapes? That question may well become one of the more important questions that environmentalists will have to answer over the next years and decades, because there will be places where the local, state, national, or even global interest is in “despoiling” a natural landscape in favor of developing a wind, solar, goethermal, cellulosic ethanol, or other renewable energy resource. This very question was asked of the Scottish government by wind turbine energy developers in the U.K., and according to the Independent, the Scottish government voted to turn down the development.

The problem, according to the Independent story, was that the 181-turbine development was going to be constructed on the Lewis Peatlands special protection area, an area that is granted special EU protections from development due to its importance to birds as a breeding ground. The Scottish government concluded that development of the wind farm would have had “significant adverse impacts” on the peatlands.

It would have involved 88 miles of road, eight electrical substations, 19 miles of overhead cables, 137 pylons, 18.3 miles of underground cables, and five rock quarries.

In the desert southwest of the United States, environmentalists will have to choose between solar thermal or geothermal energy and unspoiled desert vistas. In places like Appalachia, west Texas, and Colorado, environmentalists will have to choose between wind farms that create noise and chop up unspoiled views with roads and turbine blades. Along coastlines, environmentalists will have to choose between tidal and wave generation turbines and buoys (respectively). The decisions will not always go one direction or the other, and new legal or negotiated frameworks to avoid years of court battles that we cannot afford will have to be developed. Ultimately, though, we will have to make sacrifices in support of decarbonizing our civilization, and not all of those sacrifices will be monetary.

We may have to modify our perception of natural beauty to include solar panels, wind turbines, and the occasionally mowed tallgrass prairie.

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