Wednesday, July 26, 2006

Good Discussion of Reforestation (With Some Critique)

Climate Change Action Blog

With a small debate with, a commercial carbon-credit funded reforestation group.

Monday, July 24, 2006

The Dirty Secret -- Critique of FutureGen Coal Plant etc.

Just read a very detailed and excellent article about FutureGen and other fossil-fuel carbon reduction technologies. Give it a look. In fact, go buy this issue of the magazine, it's full of global warming articles.

Technology Review: The Dirty Secret, July/August 2006


Today there is a patch of land in Great Bend, OH, where an advanced coal plant may one day be built. The plant could eventually include equipment for siphoning off carbon dioxide. But it's not FutureGen, which today remains a collection of research projects. No FutureGen plant has been constructed, and no site for one has been chosen. The proposed plant at Great Bend could more appropriately be called "PresentGen." The technology involved doesn't demand a White House neologism suggesting that clean coal is something for which we must wait.

If IGCC is more than ready, its benefits are apparent, and sequestration seems plausible, why aren't plants that at least make carbon dioxide capture simpler getting built? "I don't necessarily think the technology is the limiting step. What's not there is the economic incentive, of course," says Howard Herzog, a chemical engineer at MIT, who manages an industrial consortium called the Carbon Sequestration Initiative. AEP estimates that IGCC plants with carbon sequestration could carry a 50 percent overall cost premium compared with traditional plants.


To date, pumping carbon dioxide underground has mainly been a way to push more oil to the surface; the primary objective wasn't really to store carbon dioxide permanently. So a critical question remains unanswered: will carbon dioxide stay where you want it?

In an old steel-walled lab at Los Alamos National Laboratory in New Mexico, geochemist George Guthrie holds out a smooth chunk of cement the size of a sea scallop. The chunk was recently drilled out of cement poured more than 50 years ago to plug the pipe in an old Texas oil well that had been crammed with carbon dioxide to enhance oil recovery. Guthrie holds up the chunk: a quarter-inch swath of it is the color of an orange Creamsicle. This staining, Guthrie says, is acid corrosion induced by carbon dioxide, which forms carbonic acid when it mixes with groundwater.

The chunk is a kind of Rorschach test. On the one hand, it could be read to imply that the carbon dioxide damaged the cement plug. On the other hand, it might imply that the damage was minimal -- and may not progress further. There's a lot riding on the answer. If the plug on a reservoir blew, the carbon dioxide could be released -- and the climate benefits of sequestration would, as it were, vanish into thin air. "There are significant consequences for doing this wrong," Guthrie observes. "On the other hand, it may be that much of the technology for doing this right already exists. There has been such enthusiasm behind [sequestration] that it is easy to forget about the implications of doing this on such a large scale."

There is reason for guarded optimism. The Statoil project and the Dakota gasification plant have already stored 20 million tons of carbon dioxide each; a gas field in Algeria has stored 17 million tons; a project in the Netherlands, eight million. The U.N.'s Intergovernmental Panel on Climate Change estimates -- based on experience and on models -- that properly engineered systems could retain 99 percent of their carbon dioxide over 100 years and would "likely" do so over 1,000 years.

Saturday, July 22, 2006

First Annual Ranking of Top 3 Carbon Sequestration Technologies

Editors note: At some point you have to sit down and try to pick your favorites from a range of new options. Here we go....

First Choice: Iron Fertilization

Feasibility: Good
Scalability: Excellent
Cost: Low
Risk: Low (see explanation below)

Iron fertilization is an interesting story. It has the best potential feasibility, low cost, and “scalability” -- in theory it could be scaled up to very large amounts. Actually it would be better if considered on a smaller scale…more about that below.

Yet as we’ve discussed in earlier posts ( link1, link2, link3), it has attracted major resistance and triggered hysterical prognostications of doom and environmental devastation by certain critics. Investigation of the science has been painfully slow, even stalled. The situation is so sad that we’ve published an Open Letter to the Marine Science Community .

Risks have probably been overblown or misinterpreted. Although there is a chance that the technique won’t work or will cause damage, it’s more likely that it can be tuned to be safe, controllable, and positive for the ocean ecosystem.

How to resolve the impasse between critics and proponents? Why do we think this process deserves a “low” risk rating? Here’s a proposal:

The sticking point has always been size. Scientists debating the process have assumed, as a starting point for discussion, that iron fertilization must be done on a massive scale to soak up all of mankind’s excess carbon (so-called “geo-engineering”). But this is a logical fallacy – it is not necessary to evaluate the process only on a gigantic scale. And in any case, the consensus of the world climate change community is that no single technology is expected, or even desired, to do the entire job single-handedly.

So what if we focus on small and medium-scale applications? Even staunch critic Sallie Chisholm stated that iron fertilization if done in local patches would be likely safe, could be monitored, and would not affect the ecosystem permanently.

Is this a workable strategy? Absolutely. Consider that any commercial or government agencies starting these projects, at least in the first few decades, could only do projects which by definition qualify as “small” on an oceanic scale, even if they sequester a comparatively large amount of carbon. Projects would naturally start small, grow slowly. Even if faster growth was possible, the available investment money wouldn’t support it. All activity, in order to qualify for carbon credits, would have to be completely transparent for oversight by concerned parties.

The key step, as anyone experienced with environmental restoration, is to get out in the field and give it a try. A reasonable approach would be a partnership between commercial ventures, willing to risk seed capital, along with major ocean science labs, willing to study feasibility and underlying processes, both working under the aegis of the Kyoto development mechanisms, and closely monitored by science and environmental groups.

As these first projects begin, this will funnel significant new funding into the monitoring and testing of deep ocean conditions by growing ranks of marine scientists. This growth in funding and public attention would itself provide additional data on long-term effects.

Above all, the Marine Science field needs significant funding increases to accelerate their understanding and resolve further questions. Given the enormous sums being poured into much less likely and more risky technologies, this one is getting shortchanged

For all these reasons, we believe that Ocean Iron Fertilization is still the best opportunity in sight, if it is approached less emotionally, and more practically.

Second Choice: Reforestation and Agricultural Sequestration

Feasibility: Excellent
Scalability: Poor
Cost: Moderate
Risk: None

Who doesn’t like growing more trees? If we can grow more trees intelligently, we can restore forestlands, improve quality of life, and create a short-term fix to remove a bit of carbon dioxide from the air at the same time.

Reforestation projects are underway in a hundred different locations in the developed and developing world. There are still obstacles, but the risk is non-existent and the science well understood.

Note that reforestation and improved agricultural practices fit the long-term trends of the world. As people move to less agrarian lives, they are removing the burden of over-cutting that has reduced forests, and appreciating the pleasures of restored forestlands. Reforestation therefore has social and national benefits, in addition to its environmental benefits.

In the tropics, this process has yet to take hold. Deforestation, slash-and-burn framing, is still an enormous problem. Reforestation for carbon credits could be one more tool to prevent this.

It’s good for the land, good for the animal species, good for the ecosystem, and good for the human soul. It’s a win-win.

Unfortunately, Reforestation is a slow-growth business that has some significant limits on size and scale. Planting trees is slow, and growing trees is slow. It’s expensive to do. Therefore it drops to second place in our ranking.

Third Choice: Geologic Sequestration

Feasibility: Poor
Scalability: Excellent
Cost: High
Risk: Moderate

Finally, there is geological sequestration. Despite great unknowns, this is the biggest “technologically driven” method of sequestering fossil fuel emissions, most significantly from coal burning power plants.

Coal is the economic driving force for many nations, including the US and China. While it’s nice to dream that we could shut them down, the fact is, global warming or not, we’re not going to. That kind of political will doesn’t exist and it never will exist, despite the hopes of the Green community. The best option we have, which almost all politicians acknowledge, is to try to store away the carbon while we continue converting energy infrastructure to non-carbon emitting.

The key to geologic sequestration is that it can be done with exhaust gases straight from the emitter. For this reason it has a certain attraction.

The strategies studied include:

1. Coal seam injection – CO2 is pumped deep into un-reachable coal deposits, where is soaks into the coal.

2. Oil well injection – CO2 is pumped into oil fields, where it helps push the oil up and out. Eventually, after the oil is gone, the wells are capped and the CO2 is kept inside.

3. Underground brine or rock formations -- CO2 is pumped deep into underground brine salt or rock formations which seem capable of containing the gas permanently.

In theory these methods could store monumental amounts of gas. There is a lot of territory underground. Coal seam and oil well are especially attractive for simple reason that they seem to put “back” the carbon where it was taken “out”. Of course this isn’t exactly correct, and any engineer would shake his or her head. Oil well injection has an even better story: it helps pump out more oil. This may mediate the cost somewhat.

Unfortunately, geological sequestration has significant risks and uncertainty as well.

- It’s very cost intensive. The cost of separating and compressing the gas, then pumping it underground, is significant. Best estimates show that geological sequestration would increase the cost of coal generated power, for example, by 25 to 50%

- Nobody is sure it will work. This is a very big engineering challenge. Power plants emit huge clouds of gas every day. If pumped underground it could easily leak from many cracks and fissures.

- It could be risky. If a “cap” were to pop and a huge body of gas rushed out, it could smother humans and animals near the ground.

- Easy (and a lot of incentive) to cheat. Here’s the problem that few people mention. Unlike other types of sequestration, this one is a direct daily expense for a coal plant. Every hour they run the compressors to pump the gas underground, they are losing thousands or perhaps millions of dollars. If they could just turn those pumps off, suddenly they would be making a LOT more money. For a typical power plant manager, who is probably paid his annual bonus based on how efficiently he runs his plant, the temptation to cheat, to “let the compressor break”, to “accidentally turn it off” would be unbearable. It’s an invitation to cheat the system.

Geological sequestration is therefore our 3rd choice for carbon sequestration. It has a long way to go to prove it can work, but the potential it huge.

Open Letter to the Marine Science Community: Has Personal Bias Derailed Science?

Has Personal Bias Been Allowed to Derail the Normal Progression of Ocean Fertilization Science?

An Open Letter to the Marine Science Community

Given the extreme hazard of global warming, the recent revelations of ocean acidity, and reports of bio-system collapse of various sorts, one would think that the concept of Ocean Iron Fertilization would get be treated most seriously. Although controversial and not yet completely proven, this technology still might be very important to the world. As Ken Johnson of Monterey Bay Aquarium Research Institute said: “We’re headed towards climate conditions that Earth hasn’t experienced in millions of years…We can’t afford to ditch any potential solutions just now.”

For a technology of such potential, one would think that marine scientists would have been diligently researching it, discovering in detail the underlying mechanisms, proposing methods to optimize or control such a process, and preparing to advise, in a rational and unbiased fashion, the decision makers and public of the world.

Unfortunately, this doesn’t seem to have happened. Reviewing the literature of the past decade, there seems to be an inexplicable lack of progress understanding the science. Worse, there seems to be a general hesitation and even hostility by the marine sciences to the progress of this field, and in many cases arguments of political feasibility are being substituted for factual arguments.

We cannot help but suspect that this is because certain key individuals are personally opposed to the concept. These people have political and personal convictions that the process is immoral, or that the world community cannot be trusted to have it. Based on these personal convictions, these scientists have steadily opposed the field the field, in some cases quite openly, slowing down research and discouraging advancement. It’s a process of “negativization” of science which is so pernicious and difficult to fight.

Some may believe that scientists have an ethical and moral right to discourage research that they believe is dangerous. That may be true in the case of weapons or obvious dangers. But this is not that kind of technology. It is not obviously harmful or destructive. In fact, if finally proven out and used smartly and carefully, this technology could be extremely beneficial to world, not only as a carbon sink but as a one tool for restoring damaged sections of the ocean. Contrary to the somewhat frantic rhetoric of the opponents, there is absolutely no reason to assume that the technology will be “easy to abuse” or will spin out of control; quite the contrary, the very size of the ocean and the scale of effort precludes such abuse. There is every reason to assume it will be possible to control and monitor to the satisfaction of all, especially on a small-to-medium scale. Yes this will require a lot of hard science and engineering, to identify the proper procedures and protocols, but this is nothing unusual – other fields such as terrestrial ecological restoration have successfully overcome similar uncertainties, and there is no reason ocean fertilization couldn’t do the same.

Critics are opposed not because it’s inherently bad, or because they possess a complete understanding of it, but because they “believe” that it’s impossible for the human race to use it smartly or carefully, they “worry” that it “might” be misused at some unspecified time in the future. They believe that commercial firms or corporations, driven by the profit motive, are inherently abusive and will “pollute the commons” for greed. These people don’t appear to have come to these conclusions based on facts or analysis, but because they disliked the concept from the very first moment they heard it, and have subsequently filtered all new data to fit their pre-conceived views.

These views aren’t science, not based on facts are logic. They are just opinions (and rather emotional, extreme opinions at that) of a few individuals. And so may we ask: why are personal beliefs detouring the progress of a major science? Is this appropriate?

Case in Point: Dr. Sallie Chisholm

Dr. Chisholm is an accomplished and respected head of an MIT laboratory and a member of the first iron experiment cruise. Yet Dr. Chisholm’s entire contribution to the field has been to oppose it, apparently from the very beginning.

From Science News, September 30 1995, p 220:

(Before the first cruise, which Chisholm was on) Oceanographer Sallie W. Chisholm of the Massachusetts Institute of Technology often argued with him (Martin) about the ethics of geo-engineering, or even of conducting research toward that goal…

“I think it’s folly. It would just cause another environmental problem,” says Chisholm. “It’s so naive to think that we can do one thing and it’s going to have a predictable effect. The arrogance of human beings is just astounding.”

The picture here is quite clear. Dr. Chisholm has thought the concept was “folly” and was actively lobbying to prevent even the research towards it, even before the first cruise. She
believes that the human race – the other 6 billion human beings and their elected representatives – are too arrogant to even have the chance to choose. Her mind appears set was set before any data was even collected, and has not changed since.

In keeping with her views, Chisholm has written papers, convened symposiums (see below), and lobbied government agencies, all for the single purpose: to ensure that her view of right and wrong is upheld.

None of these actions are by themselves inappropriate. Dr. Chisholm has ever right to lobby for her views. However, it is important to understand that by these actions, Dr. Chisholm is has assumed the role of an activist, or political partisan, not a scientist. She has made it her mission to stop any development of the field, and has used her scientific position to do this, fighting by every means possible to slow down or block this technology, for reasons of personal ideology.

Most likely her views will continue to be debated in the political sphere, at some point in the future when and if a large scale process is proposed. But right now, it’s important to ask the question: Is the ocean science community making a clear distinction between Chisholm the activist and Chisholm the respected scientist? Are they making the necessary allowance for her personal bias? And finally, are her personal views, as strongly worded as they are, acting to obstruct or prevent the normal process of scientific investigation for this nascent field, thus preventing the world community from getting a complete presentation of the facts necessary to make informed decisions?

Case In Point: Dr. Kenneth Coale

From Science News, September 30 1995, p 220:

“We had predicted the response, but none of us was really prepared for what it would look or feel like,” says (Kenneth) Coale, a researcher at the Moss Landing (Calif.) Marine Laboratories. “There were some of us who were quite pleased and others of us who would walk out on the fantail and burst into tears. It was a profoundly disturbing experience for me"

Coale and many others who witnessed iron’s tremendous greening effect loathe the idea of tinkering with the globe in such a heavy-handed way.

From Discover, October 2003 “Watery Grave”

Coale thinks it's unfair, if not impossible, to expect the oceans to absorb more than 6 billion tons of excess carbon each year. "There are many of us who consider the oceans to be sacred," he says. But "we've let the cat out of the bag. We have to keep looking at it now, whether we like it or not."

“Iron fertilization for geo-engineering or fish product has been driven by a kind of quick-buck philosophy…”
Note the phrases “burst into tears” “profoundly disturbing” “loath” “sacred”. Clearly Dr. Coale has strong emotional feelings about the entire business. Again, Coale is entitled to his opinions, but we must point out: he is the director of the Moss Landing Laboratory, and is therefore in charge of what is arguably the central lab studying the effect.

If Coale has such virulent feelings on the topic, which he expresses in almost every article written on the subject, how can he support unbiased research into the topic? How could any young researcher or student working under him dare to work optimistically on the subject when the leader of their group is so firmly opposed to it?

It seems more likely that Coale’s conflict of conscience spills over into the field that he leads, and that this negativity creates a wet blanket smothering progress.

Again, this should not be taken as personal criticism of Coale. We have no doubt that he is a dedicated leader of his group who honesty tries to do justice to the problem. But it seems unlikely he is able to do so.

Case in Point: American Society of Limnology and Oceanography (ASLO) 2001 Ocean Fertilization Symposium.

The ASLO conference was billed as a symposium with presentations by a wide variety of interested parties. From this description, an average scientifically-literate citizen or government regulator would suppose that it represented an unbiased, or at least broad, view of the issues. This symposium created a “Policy Statement” which warns against ocean iron fertilization. Such a warning might very strongly affect the views of the public.

The problem is, this conference appears to have been biased from the start, organized for the sole purpose of creating such a warning. The lead-off speakers for the conference were the two mentioned above, Chisholm and Coale. Chisholm gave the overview presentation, in which she made it very clear the purpose of the conference was to warn against the technology. So the question must be asked: how can such an event, organized in this way, possibly have arrived at an unbiased consensus of views? Of course it couldn’t and wasn’t intended for that purpose. Thus it is not a “scientific” event but an “activism” event, the equivalent of a political rally, which has been clothed as science to gain it increased respect.

If this meeting was nothing more than a meeting of activists for one particular side of the debate, then it needs to be clearly labeled as such, so that future decision-makers won’t give it more consideration than is due such activism.

Withholding Science From Society?

Scientists are entitled to their political opinions. But when those opinions become the driving force for an entire scientific field, we question if this veers into ethical conflict.

Individuals, no matter how strongly they may feel, do not have the right to obstruct the normal progress of scientific discovery and commercialization, in order to satisfy their personal beliefs. In fact, to some extent scientists have a larger obligation to research diligently and present unbiased facts so that the world community and elected representatives can make their own decisions. There are billions of citizens of the world who, through taxes, grant money, and goodwill, are funding scientific research, and who expect in return to get conclusions untainted by the personal beliefs.


· We respectfully suggest that the ocean science community needs do some “soul searching” if systemic bias has affected the progress of this research.

· We believe that the literature of the field deserves a complete review to identify places where “negative spin” has been added prematurely, or where political or social commentary has been used to argue feasibility.

· We suggest that the 2001 ASLO Symposium findings (Summary Statement April 25, 2001) be formally stricken and a new symposium be convened, in which a legitimate and valid cross-section of opinions, both pro and con, are represented.

· Finally, we suggest that researchers refrain from such negative remarks about commercial firms. Academic-commercial partnerships are a well-proven structure for making progress and solving problems. There is no need for scorn.

If we are off-base or over-stating the problem, then we apologize. This letter is certainly not meant as an accusation, but instead, a serious question: has the Marine Science community gotten “off track” in regards to Ocean Fertilization, and if so, can it get back on track?

Steve Kerry
CarbonSequestration Blog

Note: Responses welcome, and will be published in entirety in the Carbon Sequestration Blog. Please address or visit

For more information on Ocean Iron Fertilization visit Wikipedia, the Free Encyclopedia:

Prior posts on this subject:

7/26/2006 Addendum

Once criticism that might be levelled at this open letter--it didn't address any of the specific pros and cons of iron fertilization. Some might complain that we've only discuss the tone of the debate but not the actual issues. This omission was intentional. There simply wasn't room to address the issues in detail.

We did make a few points in the "Top 3" post. In summary:

1. It seems the biggest problem is that iron fertilization is debated primarily as a "geoengineering" technology. This is fallacious. The world climate change community is not looking for "big" technologies that are going to "fix the entire problem." That is no longer viewed as a realistic or even preferred approach. Instead the current consensus is for a large mix (or portfolio) of many efforts, some that reduce carbon emissions and some that sequester or remove carbon, which are applied across the globe in a multitude of ways, and which add up to the solution.

Iron fertilization therefore should be viewed just as one of many of these different techniques -- yes, a very promising one, but not a single point solution. By looking at it on this more moderate scale, we can avoid the exaggerated claims and extremist arguments seen from both sides.

2. It has not been clear which arguments are scientific and which are philosophical. For example, when someone says, "we shouldn't use iron fertilization, we should reduce energy consumption" that argument has nothing to do with science or even risk--it's about ideology.

7/27/2006 Addendum

This article has received a few emails both pro and con. One thing I want to make very clear: this is not intended specifically as an endorsement of commercial iron fertilization. This is purely an attempt to start open debate on a wider scale. If this post in any way facilitate wider debate, then it's a success.

Saturday, July 15, 2006

NETL Carbon Sequestration Newsletter July 2006

Link Here


Department of Energy Press Release, “US and
South Korea Sign Agreement on FutureGen Project.”

Associated Press, “States Vie For Next-Generation Power Plant

Powerspan Corp. Press Release, “Powerspan CO2
Pilot Combined with FirstEnergy Carbon Sequestration
Project Offers Unique Testing Opportunity

NETL Press Release, “Sequestration Test to Demonstrate
Carbon Dioxide Storage While Increasing Oil

Times-Colonist (Canada), “Prairie Project Captures

“Brennan Takes Helm of US Climate Change Science

“Carbon Value Analysis Tool (CVAT) Released By
World Resources Institute.”

LCG Consulting Online, “Construction Begins on Carbon-
Free Coal Plant.”

The Japan Times, “Underground CO2 Storage Planned.”

The Engineer Online, “Carbon Capture Ready Clean Coal

Reuters, “Gore To Train 1,000 to Spread Word About

Greenwire, “National Academy of Science Finds
‘Hockey Stick’ Graph’s Conclusion ‘Plausible’ ” and
The National Academies Press Release, “ ‘High Confidence’
That Planet Is Warmest in 400 Years; Less
Confidence in Temperature Reconstructions Prior to

Thursday, July 06, 2006

Recent Critiques of Carbon Sequestration

Congress May Insure Against Coal-Induced Flatulence

According to a recent "Inside EPA Weekly" report “Members of Congress, theEnergy Department (DOE) and industry are debating ways of shielding participants in DOE's FutureGen power plant project from potential liabilities for storing the resulting carbon dioxide (CO2) emissions underground, as part of an effort to build a landmark near-zero emissions power facility”…”the discussion highlights one of the significant unresolved issues facing FutureGen and subsequent facilities that inject large quantities of CO2 into the ground as a way to minimize global warming”. We can imagine a scenario around this. Half-way through the operating life of a “FutureGen” plant, Terra wafts a robust leak, letting go years worth of “sequestered” CO2 in a short period. Stand back stratosphere, here it comes!

Carbon Sequestration: An Idea Whose Time Has Gone?

Ooops. Turns out that burying CO2 from power plants may not be such a good idea after all. Apparently the stuff turns into a nasty chemical mix that erodes the ability of sandstone to keep the stuff underground!

Carbon Sequestration, Speed Bump or Wall?

Richard A. Kerr writes in Science: "Scientists testing the deep geologic disposal of the greenhouse gas carbon dioxide are finding that it's staying where they put it, but it's chewing up minerals. The reactions have produced a nasty mix of metals and organic substances in a layer of sandstone 1550 meters down, researchers report this week in Geology. At the same time, the CO2 is dissolving a surprising amount of the mineral that helps keep the gas where it's put." It's not leaking so far, but it will require a second look before carbon sequestration can be used on a large scale.

Technorati: Carbon Sequestration, Global Warming, Coal, Acidification, Carbon Dioxide

Sunday, July 02, 2006

More on FutureGen

FutureGen Update

Link to Wikipedia

From Wikipedia, the free encyclopedia:

"FutureGen is a project of the US government to build a zero-emissions coal-fired power plant that produces hydrogen and electricity while using Carbon Capture and Storage.

FutureGen will be a 275-megawatt power plant expected to take 10 years to build and whose cost will be shared - $620 million by the Department of Energy and $250 million by a large consortium of coal mining and power industry companies. It will be operated as a research facility.

FutureGen will seek to sequester carbon dioxide emissions at an operating rate of one million metric tons per year in order to adequately stress test a representative portion of a geologic formation (with a capability up to two million tons per year). [1]

States have bid to host the demonstration project, and foreign participation has been solicited (since by 2020 more than 60% of anthropogenic greenhouse gas emissions are expected to come from developing countries) - as of June, 2006, South Korea and India had joined the U.S. in a partnership. [2]

In May 2006 seven states submitted proposals to host the FutureGen project. These sites are in or near:
Effingham, Illinois
Marshall, Illinois
Mattoon, Illinois
Tuscola, Illinois
Henderson County, Kentucky
Bowman County, North Dakota
Meigs County, Ohio
Tuscarawas County, Ohio
Odessa, Texas
Jewett, Texas
Point Pleasant, West Virginia
Gillette, Wyoming

Future plants based on FutureGen should qualify for several provisions of the Energy Policy Act of 2005."

Technorati: Carbon Sequestration, Global Warming, Coal, Carbon Dioxide