ecoli Posted July 12, 2006 Posted July 12, 2006 We haven't even got to the ocean yet. That's a lot more that 75 Billion Tons. Many people think that the ocean is a safe unlimited sink for carbon dioxide. But, this is not the case. CO2 can either be trapped in the open ocean, or drop into the bottom waters. The excess CO2, within limits can be absorbed by the excellent bicarbonate buffering system (similiar to that of the blood), but when pushed to the limits, the acidity of the ocean systems can still be thrown off. (like acid rain) The CO2 trapped in deep water can be kept under the waters for thousands of years, but eventually it will rise to the top and the CO2 will be realsed again. And you still have the acidity problem.
silkworm Posted July 13, 2006 Posted July 13, 2006 Many people think that the ocean is a safe unlimited sink for carbon dioxide. But' date=' this is not the case. CO2 can either be trapped in the open ocean, or drop into the bottom waters. The excess CO2, within limits can be absorbed by the excellent bicarbonate buffering system (similiar to that of the blood), but when pushed to the limits, the acidity of the ocean systems can still be thrown off. (like acid rain) The CO2 trapped in deep water can be kept under the waters for thousands of years, but eventually it will rise to the top and the CO2 will be realsed again. And you still have the acidity problem.[/quote'] I heard recently there is a marine organism that uses carbon dioxide and excretes calcium carbonate pellets that are stored very nicely and safely in the deep ocean. They're incredibly fragile though. Anyway, the excess carbon dioxide in the ocean is a MAJOR problem and a threat to all marine life, and also everything on earth, by lowering pH, but hopefully these critters have a population explosion and can sink enough to deal with this problem. I heard about it on the TWIS (This Week in Science) podcast. It's the July 4th show here, and they talk about it at 15 min, 50 second into the show. I recommend listening to it, the numbers are impressive.
DrCloud Posted July 13, 2006 Posted July 13, 2006 I heard recently there is a marine organism that uses carbon dioxide and excretes calcium carbonate pellets... Not exactly (but close). The foraminifera to which I referred in the proxy thread ("How do we know temperatures thousands of years ago"; unfortunately, this has degenerated into the same bickering that other climate threads have) and the mud in the cooler Europe thread relate to this. That mud -- the ocean-bottom sediments -- consists of zillions of calcium carbonate shells of the forams. These little ocean creatures (not photosynthetic plankton; rather they're zooplankton that eat the green stuff) make little shells for themselves, and when they die their shells fall to the ocean floor. Eventually, it becomes limestone. First, though, it's fodder for the deep-sea drilling program, which sends out ships to take sediment cores. Then scientists (mostly graduate students) analyze the cores for the species of forams and, from abundances, infer ancient temperatures. (When I was a graduate student, people made their bones by spending hours and hours looking through binocular microscopes doing manual counts. I'm thinking it may be computerized by now, but I don't know.) This process represents one of the major, permanent sinks in the global carbon budget. Speeding it up somehow would be useful as a way to (eventually) balance the increased carbon loading in the atmosphere due to fossil fuel burning. One issue is the increasing acidity of the oceans (which is becoming measurable) associated with their uptake of CO2 from the atmosphere. This changes everything, including the survivability of the critters and the chemistry of their calcium carbonate production. I'm not suggesting anything catastrophic here, just something complicated. It's got the specialists in the field in something of a twitter. HPH
SmallIsPower Posted July 13, 2006 Posted July 13, 2006 from bascules first link: There has been some emphasis that the notion of planting trees will make a significant difference to the carbon loading in the atmosphere. To be able to absorb the excess annual loading of 3 Gt would mean that about 15 Gt of extra trees would need to be grown each year and this would do nothing for the carbon already added as a result of human activity. Some of this would be returned in the short term as a result of rotting leaves. What exactly does this mean? The General Sherman tree in the Sequoia National Park in California is estimated to weigh a little over 6 kt; it would therefore require an extra annual growth equivalent to 2,500,000 such trees, just to sequester the excess carbon dioxide we are adding to the atmosphere each year, and we would have to repeat this feat every year. The General Sherman Tree has a diameter of 36 feet Let's assume it's root structure has a diameter of 100 feet, or a radius of 50 feet A=pi*r*r =7500 sq ft 3000 GSTs = 1 sq mile 2,500,000 GST's = 800 sq mi Earth's Surface Area = 4pi*r*r 800,000,000 sq mi Earth's landmass = 240,000,000 sq mi Also from the first link Of course, sequoia trees are not ideal for this, and smaller fast-growing species, such as willows, pines, hazel etc. would be more suitable. Ecoli, can you see how cutting a few trees can add lots of CO2?
ecoli Posted July 13, 2006 Posted July 13, 2006 Ecoli' date=' can you see how cutting a few trees can add lots of CO2?[/quote'] Oh of course. I only meant that I was doubtful that anthropogenic CO2 emmisions isn't the main cause. And keep in mind that CO2 isn't the only greenhouse gas we have to worry about.
silkworm Posted July 13, 2006 Posted July 13, 2006 Not exactly (but close). The foraminifera to which I referred in the proxy thread ("How do we know temperatures thousands of years ago"; unfortunately' date=' this has degenerated into the same bickering that other climate threads have) and the mud in the cooler Europe thread relate to this. That mud -- the ocean-bottom sediments -- consists of zillions of calcium carbonate shells of the forams. These little ocean creatures (not photosynthetic plankton; rather they're zooplankton that eat the green stuff) make little shells for themselves, and when they die their shells fall to the ocean floor. Eventually, it becomes limestone. First, though, it's fodder for the deep-sea drilling program, which sends out ships to take sediment cores. Then scientists (mostly graduate students) analyze the cores for the species of forams and, from abundances, infer ancient temperatures. (When I was a graduate student, people made their bones by spending hours and hours looking through binocular microscopes doing manual counts. I'm thinking it may be computerized by now, but I don't know.) This process represents one of the major, permanent sinks in the global carbon budget. Speeding it up somehow would be useful as a way to (eventually) balance the increased carbon loading in the atmosphere due to fossil fuel burning. One issue is the increasing acidity of the oceans (which is becoming measurable) associated with their uptake of CO2 from the atmosphere. This changes everything, including the survivability of the critters and the chemistry of their calcium carbonate production. I'm not suggesting anything catastrophic here, just something complicated. It's got the specialists in the field in something of a twitter. HPH[/quote'] Unless I'm missing something in your post, we're talking about different things. I wasn't referring to foraminifera, or single celled organisms. I was referring to jelly-fish type creatures that are thumb size, Salps. I know they're fragile, but I don't know how low pH can fall before it hurts them. http://www.sciencedaily.com/releases/2006/07/060702085004.htm In the May issue of Deep Sea Research, scientists report that salps, about the size of a human thumb, swarming by the billions in “hot spots” may be transporting tons of carbon per day from the ocean surface to the deep sea and keep it from re-entering the atmosphere. Salps are semi-transparent, barrel-shaped marine animals that move through the water by drawing water in the front end and propelling it out the rear in a sort of jet propulsion. The water passes over a mucus membrane that vacuums it clean of all edible material. One swarm covered 100,000 square kilometers (38,600 square miles) of the sea surface. The scientists estimated that the swarm consumed up to 74 percent of microscopic carbon-containing plants from the surface water per day, and their sinking fecal pellets transported up to 4,000 tons of carbon a day to deep water. In previous work, Madin and WHOI biologist Richard Harbison found that salp fecal pellets sink as much as 1,000 meters (3,280 feet) a day. The scientists also showed that when salps die, their bodies also sink fast—up to 475 meters (1,575 feet) a day, faster than most pellets.
SmallIsPower Posted July 13, 2006 Posted July 13, 2006 If there was ever a good purpose for genetic modification it would be to engineer creatures to: Sequester more CO2 Clean up ecosystems so that carbon sequestering orginisms can thrive
ecoli Posted July 13, 2006 Posted July 13, 2006 That's incredible silkworm. I've heard of salps, but I didn't realize how cool they are.
DrCloud Posted July 14, 2006 Posted July 14, 2006 Unless I'm missing something in your post, we're talking about different things. Right. I didn't mean to veer completely off the topic; I was trying to merely to focus on the largest of these oceanic sink mechanisms. Yes, salps do all this; but the amount of carbon involved isn't really that significant in the global budget -- at least unless the population is orders of magnitude larger than thought. HPH
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