Global Warming – Carbon Sequestration 101

Carbon Sequestration is one of the four big things that ought to be done to mitigate the threat of drastic short-term climate change.  The other three are:

   

• get over our nuclear-phobia;

• convert our cars and trucks to fuel-cells (need nukes to charge them);

• make some rational trade-offs like accepting the sight of wind turbines on ridge lines in turn for air clear enough to see the ridge line.

I know I left conservation off the list.  Not that conservation isn’t a good thing; I’ve blogged about it here; but better gas mileage in the US car fleet simply isn’t going to matter significantly in worldwide carbon dioxide production compared to what happens when the third of the earth’s population that live in India and China get their first cars assuming all these cars have oil-fired engines.

Back to carbon sequestration.  As the unsexy name implies, this is the practice of putting carbon dioxide into the ground instead of releasing it into the atmosphere - certainly makes superficial sense since the carbon was in the ground as part of hydrocarbon deposits before we burned it to extract energy.

 

Sequestering carbon dioxide is a lot simpler than, say, disposing of nuclear waste.  A little leakage doesn’t make any difference.  Even a successful terrorist attack on a carbon dioxide storage site wouldn’t create any hazard other than the attackers themselves.

   

One natural place to put carbon dioxide is back in the wells or mines that the hydrocarbons initially came out of.  In some cases re-injecting carbon dioxide in an oil or natural gas well could actually help recover a greater percentage of the fuel in the well. We may well see electrical plants built near coal mines to avoid transporting both the coal and the carbon dioxide.

 

An MIT-sponsored study estimates that, in 2012, sequestering carbon dioxide would add 30% to the price of electricity generated from coal.  They are assuming “conservatively” that the cost of sequestration at the time will be $37 per ton of carbon. Since the study was done before the recent spike in energy prices and they didn’t assume such a spike in their model, the actual percentage increase is probably less (because the coal costs more).  According to the study, Over 95% of coal burned in the US is used for generating electric power.

 

In my previous post I claimed that, although we know that high levels of atmospheric carbon dioxide are associated with warming periods, we don’t know for sure that they triggered these warming periods.  We do know that humans DIDN’T contribute to the high levels of carbon dioxide in previous warming periods.  We know that we HAVE contributed this time. We also know that further warming results in further buildups of carbon dioxide as tundra melts and that the result may be a powerful positive feedback loop.  Finally, we there is strong evidence that climate change happens suddenly and not gradually – in years rather than on centuries.

No question that our civilization is highly dependent both on current climate and current sea levels.  Hard to say that a warmer earth is a bad thing overall; but a quick transition would literally be hell.

 

We may be at or past a tipping point in the chaotic progression of climate.  BTW, climate is so chaotic that the result of more warming could be an abrupt cooling.  For example, fresh water from melting ice in the Artic could suddenly turn the Gulf Stream off.  May well have happened before.

 

Whether the recent acceleration in warming since the last ice age – remember, the glaciers have been melting for the last 12,000 years - was caused by carbon dioxide build up and whether this build up is all our fault or attributable to “natural” causes, it almost certainly would be a good idea to try to lower the level of atmospheric carbon dioxide. We may avoid a tipping point.  We make break or slow a rapid warming cycle if one has, in fact begun.  We almost surely WON’T reverse the interglacial warming that has been going on for the last 15,000 (it took a while for the glaciers to start melting) years and we probably don’t want to – anyone for another ice age?

 

Sorry about all the “probably” and “almost” and other weasel words but climate is chaotic and we won’t really know the results of what we do or don’t do until we do or don’t do it.  And, even then, it will be hard to say what caused what.  Only purveyors  of junk science are given the gift of absolute certainty.

 

If it turns out that we are entering a sudden cooling period, we could always release sequestered carbon dioxide and warm things up (we think).  Nice to have alternatives when you can’t be certain.

 

Carbon sequestration isn’t sexy. It doesn’t advance either the agenda of those who’d really prefer to shut down industrialization or those (including me) who’d like to see quick renuclearization.  But it’s relatively low tech, probably relatively easily achievable, and reversible.  Also promises to ease the use of America’s (and China’s and Europe’s) huge coal reserves.

I blogged about nuclear power here and here, about fuel cells here and here,  and, to maintain my green credentials, I also wrote favorably about home solar here and here.  I never installed my solar rooftop in NJ and our new home in Vermont may be too far north for that to be practical there.