Category: Global warming

Carbon Capture and Sequestration: Is It a Viable Technology?

As mentioned in my previous blog (‘What I Took Away From the Doha Clean Energy Forum’): “three speakers made a strong case for carbon capture and sequestration (CCS) as a means of addressing global warming and climate change, especially in heavily carbon emitting industries such as cement production. Lots of questions remain, and will be discussed in a future blog.” This is that future blog on a well trod but still controversial subject.

Wikipedia defines CCS as “..the process of capturing waste carbon dioxide (CO2) from large point sources, such as fossil fuel power plants, transporting it to a storage site, and depositing it where it will not enter the atmosphere, normally an underground geological formation.”

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Considerable literature exists on CCS, exhibiting a wide range of opinions on its viability as a technology to reduce carbon dioxide emissions. The principal argument for CCS is that the world today is fueled largely by coal, oil and natural gas and that this situation is not likely to change any time soon. In fact, as many developing nations industrialize and emerge from poverty, the demand for energy increases steadily and it is argued that only fossil fuels can meet that demand in coming decades. It is also argued that while solar and wind and other renewable energy technologies can eventually replace electricity from coal and natural gas power plants this will not occur quickly and people will need fossil energy during the long transition. In addition, some industries like steel and cement are not so easily ‘fixed’ and will continue to use fossil fuels in increasing amounts as global industrialization grows.

These points raised in support of CCS are countered by the following arguments:
– CCS is expensive, whether added to an existing power plant or industrial carbon dioxide source, or included in newly constructed facilities. The energy penalty for operating CCS is also high, requiring a fair amount of parasitic energy that reduces efficiency and revenues.
– When operating, CCS systems require large amounts of water.
– captured carbon dioxide must be liquified and stored for indefinite periods of time in such a way as to avoid leakage and large ‘burps’ that can be toxic. This requires identification and development of storage sites (depleted oil and gas wells, coal mines, underground aquifers), infrastructure to transport liquid CO2, adds additional costs and raises questions of liability if something goes wrong and stored CO2 is accidentally released.
– the time required for development, demonstration and large-scale deployment of CCS technology that can have a meaningful impact on global warming is too long compared to other options.

Proponents of CCS (see http://www.globalccsinstitute.com) argue that CCS costs can be brought down significantly with a sufficient number of demonstration projects and economies of scale associated with large-scale deployment. Nevertheless, at the recent Doha Clean Energy Forum even one of its supporters admitted that an impactful global CCS system will cost an estimated 3.6 trillion USD (and I did say trillion). My immediate reaction was that for $3.6 trillion I can deliver an awful lot of renewable energy that will replace coal, oil, and natural gas use in power generation and transportation. Nevertheless, there is the argument that the CO2 emissions from some industries will still be there in large and growing amounts even with large-scale deployment of renewables and CCS is the only way to limit these emissions.

These are strong arguments for some attention to CCS R&D and demonstration, but, in my view, not at the expense of rapid development and deployment of renewables. This creates a conundrum as CCS demonstrations are expensive, and the money for them would have to come from somewhere. Government funding is at best problematic in current budget situations. Other possibilities are the fossil fuel industries themselves, which have a vested interest in continued purchase of their commodities. Countries with large reserves of fossil fuels – e.g., the U.S., with large reserves of coal – will also see value in CCS allowing extended use of secure domestic energy reserves.

In a world committed to reducing carbon emissions CCS offers a helping hand but not a definitive one. It may offer a partial answer for the rest of this century, but governments are unlikely to provide the needed funds for large-scale deployment. Let’s see if the private fossil fuel sector is willing to step up to protect its vested interests.

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Update on Global Warming And The Threat Of Sea Level Rise

The following article appeared in today’s (12 August 2013) New York Times and by reproducing it here I hope to help it get wider visibility. It is one of the most disturbing articles on global warming and its possible implications that I’ve ever read. If the sea level rises mentioned in the article hold up under scientific scrutiny it foretells a significant shift in human habitation. Not only did I find the article alarming, but it also got my juices going. There are still those out there like the Heartland Institute, and even a few scientists, who deny the reality of global warming or say that its impacts will be minimal. If one believes in the scientific method the evidence for global warming is overwhelming, at least to this scientist and to the many scientists much more knowledgeable of global warming than I am. I consider it irresponsible of the deniers to continue their denial in light of this growing body of evidence.

“Timing a Rise in Sea Level
By JUSTIN GILLIS (New York Times)
Thirty-five years ago, a scientist named John H. Mercer issued a warning. By then it was already becoming clear that human emissions would warm the earth, and Dr. Mercer had begun thinking deeply about the consequences.

His paper, in the journal Nature, was titled “West Antarctic Ice Sheet and CO2 Greenhouse Effect: A Threat of Disaster.” In it, Dr. Mercer pointed out the unusual topography of the ice sheet sitting over the western part of Antarctica. Much of it is below sea level, in a sort of bowl, and he said that a climatic warming could cause the whole thing to degrade rapidly on a geologic time scale, leading to a possible rise in sea level of 16 feet.

While it is clear by now that we are in the early stages of what is likely to be a substantial rise in sea level, we still do not know if Dr. Mercer was right about a dangerous instability that could cause that rise to happen rapidly, in geologic time. We may be getting closer to figuring that out. An intriguing new paper comes from Michael J. O’Leary of Curtin University in Australia and five colleagues scattered around the world. Dr. O’Leary has spent more than a decade exploring the remote western coast of Australia, considered one of the best places in the world to study sea levels of the past.

The paper, published July 28 in Nature Geoscience, focuses on a warm period in the earth’s history that preceded the most recent ice age. In that epoch, sometimes called the Eemian, the planetary temperature was similar to levels we may see in coming decades as a result of human emissions, so it is considered a possible indicator of things to come.

Examining elevated fossil beaches and coral reefs along more than a thousand miles of coast, Dr. O’Leary’s group confirmed something we pretty much already knew. In the warmer world of the Eemian, sea level stabilized for several thousand years at about 10 to 12 feet above modern sea level.

The interesting part is what happened after that. Dr. O’Leary’s group found what they consider to be compelling evidence that near the end of the Eemian, sea level jumped by another 17 feet or so, to settle at close to 30 feet above the modern level, before beginning to fall as the ice age set in.

In an interview, Dr. O’Leary told me he was confident that the 17-foot jump happened in less than a thousand years — how much less, he cannot be sure.

This finding is something of a vindication for one member of the team, a North Carolina field geologist, Paul J. Hearty. He had argued for decades that the rock record suggested a jump of this sort, but only recently have measurement and modeling techniques reached the level of precision needed to nail the case.

We have to see if their results withstand critical scrutiny. A sea-level scientist not involved in the work, Andrea Dutton of the University of Florida, said the paper had failed to disclose enough detailed information about the field sites to allow her to judge the overall conclusion. But if the work does hold up, the implications are profound. The only possible explanation for such a large, rapid jump in sea level is the catastrophic collapse of a polar ice sheet, on either Greenland or Antarctica.

Dr. O’Leary is not prepared to say which; figuring that out is the group’s next project. But a 17-foot rise in less than a thousand years, a geologic instant, has to mean that one or both ice sheets contain some profound instability that can be set off by a warmer climate.

That, of course, augurs poorly for humans. Scientists at Stanford calculated recently that human emissions are causing the climate to change many times faster than at any point since the dinosaurs died out. We are pushing the climate system so hard that, if the ice sheets do have a threshold of some kind, we stand a good chance of exceeding it.

Another recent paper, by Anders Levermann of the Potsdam Institute for Climate Impact Research in Germany and a half-dozen colleagues, implies that even if emissions were to stop tomorrow, we have probably locked in several feet of sea level rise over the long term.

Benjamin Strauss and his colleagues at Climate Central, an independent group of scientists and journalists in Princeton, that reports climate research, translated the Levermann results into graphical form, and showed the difference it could make if we launched an aggressive program to control emissions. By 2100, their calculations suggest, continuing on our current path would mean locking in a long-term sea level rise of 23 feet, but aggressive emission cuts could limit that to seven feet.

If you are the mayor of Miami or of a beach town in New Jersey, you may be asking yourself: Exactly how long is all this going to take to play out?

On that crucial point, alas, our science is still nearly blind. Scientists can look at the rocks and see indisputable evidence of jumps in sea level, and they can associate those with relatively modest increases in global temperature. But the nature of the evidence is such that it is hard to tell the difference between something that happened in a thousand years and something that happened in a hundred.

On the human time scale, of course, that is all the difference in the world. If sea level is going to rise by, say, 30 feet over several thousand years, that is quite a lot of time to adjust — to pull back from the beaches, to reinforce major cities, and to develop technologies to help us cope.

But if sea level is capable of rising several feet per century, as Dr. O’Leary’s paper would seem to imply and as many other scientists believe, then babies being born now could live to see the early stages of a global calamity.”