Sequester means to seclude or isolate. Carbon sequestering means that CO2 gas is isolated, fixed, or hidden in some place so as not to become part of the atmosphere, either temporarily or permanently.
In Nature it happens all the time and is an essential part of the "carbon cycle" which defines what happens to the element carbon within the broader study of the Earth's geochemistry. The three major sinks for CO2 and carbon are the oceans, the biosphere, which includes all living matter, such as plants, crops, forests and animals, and the soils.
CO2 gas gets fixed, or naturally sequested by dissolving in the oceans which cover about 70% of the Earth' surface. The colder the water the more CO2 can dissolve. A warming sea will release CO2 to the atmosphere just as does a warming glass of beer or wine release bubbles when initially saturated with CO2 gas.
The global warming debate has been spearheaded by Al Gore with the publication of his scary documentary "An Inconvenient Truth" where he points out a correlation between varying global temperature and CO2 content of the atmosphere, as determined over the past 200,000 years, from ice core data. The CO2 levels peak when the temperatures peak. Al Gore and his followers say that rising CO2 levels in the atmosphere actually cause the global warming by means of the greenhouse effect of CO2 in the atmosphere.
More detailed and recent analysis of Antarctic ice core data has shown conclusively that the rise in CO2 levels of the atmosphere came about 800 years after the peak in global temperatures, which suggests that the slow warming of the oceans and release of dissolved CO2 was the cause of rising CO2 levels in the atmosphere, which is the opposite to that proposed by Al Gore.
It is essential that we get the science correct. The debate has become politicized with most Western democracies promoting the idea that we must drastically cut our CO2 emissions to the atmosphere in order to prevent catastrophic global warming. The December 2009 meeting in Copenhagen of the UN's Climate Change Conference will decide what to do, if anything. Billions of dollars are at stake due to the consequences of proposed Government policies to curb CO2 emissions, which may really be unnecessary.
The global warmers are masters of spin and linguistics to promote their cause. They operate in a parallel universe to us and use a special language, called Green Speak. Names are dropped and replaced by new ones more acceptable, or the meaning of a word or phrase may be manipulated to favor their belief system. A good example is their change from "global warming" (which hasn't happened for a decade) to "climate change", which conveniently can include any weather event.
Likewise, anyone encountering the term "clean coal technology" could reasonably expect this to mean how one cleans coal from impurities such as rock and pyrite, and to include all the processing prior to it being used as a fuel in a power station, or where ever. Like with the term "gay marriage", we are in for a surprise. "Clean coal technology" sounds wonderful but the term is now used by politicians to mean a process whereby CO2 is stripped from fossil fuel combustion gases and then sequested, or pumped into underground storage reservoirs so as to prevent it from "polluting" the atmosphere thus contributing to global warming.
It takes a lot of energy to strip the CO2 from a hot combustion exhaust gas stream and then compress it for eventual underground storage. The US utility companies' estimates on this indicate that 81% more coal will be consumed to generate the same amount of power. This means the cost of base level electricity will go up by 80% and we would burn up our coal reserves 80% faster, if we were silly enough to try and do so, and if the technology worked! This does not seem to worry the politicians!
The idea for carbon sequestration has come from practices developed on the US oil and natural gas fields. Natural gas must be refined before being used as a fuel. Propane is a useful byproduct (autogas), as is helium. Hydrogen sulfide and CO2 gas must also be removed so as to have a pure high thermal energy methane product that is piped to your home.
Natural gas has variable amounts of CO2, sometimes up to 10%, which must be removed. Ideally it would be nice to be able to sell it for some useful purpose instead of venting it to the atmosphere, or pumping it into underground storage and forgetting about it. Today much is used in the US for enhanced oil recovery (EOR) whereby it is pumped into dwindling oil wells to improve the flow rate. By this means 30 - 50% more of the reservoir's original oil can be extracted.
There is no shortage of CO2 gas being produced in the world. Today it is liberated when ever fossil fuels are burnt, such as in power stations, cement works and steel works, or from autos, airplanes and ships. The important thing to realize is that this release of CO2 into the atmosphere is a good thing and beneficial to the biosphere. It is nothing to be afraid of. This is the opposite view taken by the global warmers! It is my opinion and that of many others (1).
I object to the deliberate demonization of the element carbon and CO2 by the Greens, for which there is no justification. Carbon is the most wonderful element in the Periodic Table! Carbon forms more compounds than all the other elements put together. That is why we have a special branches of chemistry called "Organic Chemistry" and "Biochemistry". All life forms on earth are composed of carbon compounds and most depend on reaction with atmospheric CO2 for their existence and growth. CO2 does not pollute the atmosphere. How dare the Greens and EPA denigrate carbon and CO2 ; they are quite mad to do so.
My second concern is to do with politicians many of whom seem to readily support any outlandish Green proposition that may help them to stay in power. The present state of Western democracies is in turmoil due to the global financial crisis. Now this is compounded by their enthusiasm to enact ridiculous and unnecessary policies to stem global warming, including support for a proposed extension of the Kyoto Treaty to drastically cut CO2 emissions, all of which is insane. It doesn't have to be this way. Let the global warming debate continue!
Reference:
(1) "Air Con - the seriously inconvenient truth about Global Alarming" by Ian Wishart
(2009), Howling at the Moon Publishing Ltd (NZ); www.ianwishart.com