A Qualitative Discussion Regarding the Development of an Air Capture Complex

The reality of the situation involving global warming is that both reduction in carbon emissions and carbon emission remediation will be required to significantly reduce detrimental damage to the environment, damage that will influence the future survival rate of humanity. For carbon emission remediation two elements take precedence: effectiveness and speed. Effectiveness is rather self-explanatory; if the process is unable to remove more CO2 from the air than is added over the lifecycle of the process then such a remediation strategy is not worth exploring. Speed is necessary because there is already a dangerous amount of CO2 in the atmosphere and the rate of carbon mitigation is not proceeding nearly fast enough relative to the capacity of natural sinks to remove CO2.

Therefore, although there are other more cost-effective ambient air capture techniques, which involve more natural processes (planting trees or synthesizing bio-char), these processes are significantly slower than technological methods. Speed is important, not just on a general level, because also a feedback level for during the process of removing the necessary CO2 the now more acidic ocean could lose a significant amount of its sink capacity has it begins out-gassing previously absorbed CO2 back into the atmosphere due to the change in the concentration gradient, thus the process must be fast enough to accommodate any further reduced sink capacity. Also the threat of some permafrost melt will also increase atmospheric CO2 concentrations which will need to be effectively managed beyond mitigation of directly derived human emissions.

Most economists are troubled by the calculated theoretical (no large scale system has been empirically tested yet) costs of technology driven air capture ($400-600 dollars per ton of CO2) and they should be, but as explained here the options available to the global community to address global warming consequences are quite small. Realistically due to the deficiencies of natural sinks there are only two choices: rapidly deploy both emission reduction programs and direct air capture technology or prepare to live in a much harsher environment which should reduce life expectancy. The reason for the parameters of the first choice is that natural sinks (land and ocean) will be unable to remove enough CO2 from the atmosphere, even in a scenario of rapid emission reduction because there is already too much CO2 and other greenhouse gases in the atmosphere, to avoid significant detrimental environmental effects.

However, these air capture unit must be efficient, otherwise they will lose their speed advantage over augmenting natural sources. Therefore, there are some important operational issues that must be addressed before deployment. The first major issue is water use. Regardless of the system, the chemical reaction utilized to absorb CO2 from the atmosphere requires the use of water. In most situations the water is supposed to act as a catalyst, but due to the open-air nature of the reaction system a significant percentage of the water (how much is heavily based on overall process design) is absorbed into the atmosphere becoming water vapor making water recovery more difficult.

Another important consideration is that most of the costs associated with air capture relate to gross costs per ton of CO2 captured because the estimates do not take into consideration what energy source is utilized to power the capture unit. A general background regarding where energy in most system designs is utilized can be found here. If a trace emission source is utilized (nuclear, geothermal, wind or solar) then the gross cost can be reasonably estimated as 90-99% efficient (thus the net cost will be 1.01-1.1 times more than the gross cost). However, if a fossil fuel source is utilized then the net cost will be higher than the gross cost (largely dependent on the exact fuel mix), but most of the time at least 1.3-1.5 times. Not only does the use of a fossil fuel energy source increase per unit costs and overall long-term costs, but it also reduces the overall speed of CO2 removal making technology air capture less attractive vs. natural sources. Therefore, it is important that all air capture units be powered by trace emission sources.

The final consideration is developing an endpoint for the captured CO2. A number of air capture developers have dreamt to using the captured CO2 as a marketed product either to enhance oil recovery, in a methane or hydrocarbon based fuel or in commercial industry (soda, etc.). Unfortunately the first two options add CO2 back to the atmosphere, just another means of disrupting the overall extraction efficiency of these units making them less desirable relative to expanding natural sources. The commercial option is incredibly insufficient at utilizing a vast majority of the CO2 that needs to be captured (gigatons of CO2). The best means to address this glut of CO2 appears to be sequestering it underground.

With all of these additional considerations to take into account it is not wise to simply build these air capture units at random. These units clearly need to be constructed in an orderly and cohesive manner perhaps even in a localized autonomous network. This network needs to contain a water source, a power source and a means of utilizing the captured CO2 in addition to having recycling pathways for all necessary materials used in the selected air capture reactions.

The most important element in such an air capture complex is selecting a power source. Recalling that volumetric speed is one of the principle elements behind the need for technology air capture the selected power source will need to be reliable and have as little downtime (intermittence) as possible. This requirement limits the viability of using wind or solar power as those energy methodologies cannot reliably power this proposed complex 24 hours 7 days a week.

Now one could argue that wind or solar would be appropriate with storage, but the general lack of storage options and empirical track record hurts the viability of this response. For example Solar Tres uses molten nitrate salt as a storage medium, but it is difficult to conclude that enough storage could be generated on a consistent basis to generate the 24-7 operational period. Remember energy can only stored if it is in excess, which will not be true most of the time if the solar panels are already providing power to various elements in the complex. Pumped hydro shares the same problem, as well as limiting the location for the complex because of its required topography. Also the addition of a storage medium would increase the cost associated with capture.

Without being able to rely on solar or wind power due to consistency concerns, viable energy options fall to nuclear power and geothermal. Nuclear power in a conventional plant is a little tricky because the provided power would be too much for the needs of the complex, thus if nuclear power was used in this way it would have to come from an outside plant, brought in by transmission lines. Another nuclear option may be to utilize a small modular unit design for a given complex.

Geothermal power is an attractive option when considering an Enhanced Geothermal Systems (EGS) model, but not a conventional model. A conventional geothermal model is similar to utilizing a pumped hydro storage system in that it limits where the complex can be constructed. An EGS model is also attractive as a secondary means to utilize some of the captured CO2 as a supercritical fluid in the system itself. So it appears that from the perspective of the complex itself the best power sources in decreasing order of effectiveness are EGS > Nuclear > Solar > Wind.

There are two main strategies for developing a water source: desalination or atmospheric capture of water vapor. The advantage of an air capture complex is that both of these strategies can be utilized because the air capture unit itself does not rely on natural wind patterns, but creates its own direct air flow to drive ambient air into the reaction section. The only boundary condition for the unit is tied to the power source utilized. This flexibility advantage is useful because the air capture complex requires a system to provide the initial water and would be heavily aided by a system which recycles water (reduces loss from air absorption).

Therefore, the complex could be constructed near a source of salt water, use desalination to provide in the initial water supply and utilize atmospheric water condensers to limit the amount of water required from desalination after the initial reactant amount. Note that tapping a continuous water source (such as desalination) may not be necessary as long as a sufficient amount of water is made available at the beginning of the process until the atmospheric collectors can successfully begin the recycling process, it just appears to be an easier overall strategy.

Desalination use has always involved two major concerns: the energy required for the process itself and determining an endpoint for the brine. The energy requirement is not a significant issue if using one of the two best-fit energy sources for the complex. Under normal circumstances the brine is a very significant issue that has environmental repercussions as returning it to the sea (standard practice) is through to have serious detrimental effects in the localized region where it is returned. Other than injecting it back into the source, effective ideas to address the leftover brine are far and few between.

Similar to the absorbed CO2, the total raw amount of salt from the brine, which would be generated from such a desalination project, is so large that using it in commercial endeavors does not appear viable. Some have proposed ammoniating the brine and using it to increase the volume of CO2 capture. The concern with that strategy is providing the necessary ammonium to react with the brine to create a consistent and worthwhile reactant volume. Another option that has been floated is incorporating the brine into a set of molten salts that would be used in either nuclear power reactors or batteries. However, the viability of such an idea is still questionable.

It is understandable that if the economic impact of developing such a complex was quantitatively calculated that it would be high; however, the nature of the complex is that all of these elements will be required in the future based on the current environmental-use path humans have embarked upon, thus the cost is not based on luxury, but necessity. The idea behind such a complex is actually to lower costs by tying many of the air capture units into the same required operational elements, thus making the technology air capture strategy more economical, saving money for investment in other environmentally necessary avenues like emission reduction. Overall while the manifestation of such a complex may not be exactly as described in this blog post, the reality is that such a complex will be needed in one form or another.

The figure below is a crude visual representation regarding what the complex may look like without mileage delineations between units as such an element needs to be modeled to maximize the efficiency of each given operational unit.

The Correct Contextual Economic Argument for Direct Air Capture

Since the last time DAC was discussed on this blog it has received more attention including a report issued by American Physical Society. Unfortunately, yet not surprisingly, most of these discussions have focused on the economics of developing and deploying such a system over technical/feasibility discussions. Most would argue that the economic element is critically important in the modern capitalistic world as almost all decisions revolve around economics and affordability. Also efforts to reduce costs should aid in the technical development of the overall process. While both these statements are true, the problem is that most of the economic analysis is not being conducted from the proper perspective.

For example most estimates place the cost of removing 1 ton of CO2 from the atmosphere, regardless of specific design, between $450-600. Relate this cost back to the fact that CO2 has traded in the European Trading Scheme rather consistently at $20-30 per ton (meaning that it costs $20-30 dollars for a participant to emit 1 ton of CO2) and clearly application of current DAC models is too expensive.
Compounding the problem is that it is reasonable to conclude that these estimates only calculate the costs associated with capturing 1 gross ton of CO2 because they do not include the CO2 emitted to provide the energy required to capture the CO2 from the atmosphere, thus the costs now are even higher than those stated above. Overall most DAC proponents agree that this cost is too high and believe that through the additions of carbon taxes and trade programs and reductions in technical and development costs due to scale up costs will drop significantly. Also proponents believe that finding a marketplace for the captured carbon will also narrow the cost gap.

This desire for a marketplace is where the economic argument begins to breakdown relative to the environmental strategy that DAC should be following. The principle rationality behind pursuing DAC is to reduce the amount of CO2 in the atmosphere as fast as possible in order to lessen the detrimental influence of global warming, not make money or close the cost gap. Unfortunately the two most cited methods for making money from a DAC system are in contradiction to this principle rationality. The first means of ‘funding’ DAC is to use the captured CO2 in enhanced oil recovery (EOR). The problem with this strategy is obvious. The point of recovering more oil is to burn it in some industrial process or use it for transportation. Thus there is no significant decrease in atmospheric CO2. With the most optimistic scenario such a system could be viewed as very slightly CO2 negative with somewhat unjustifiable costs for that reduction. Unfortunately such a system then realistically wastes energy (energy that is used to extract the CO2 and the oil) and further pollutes the environment (recall that refining and burning oil releases other pollutants in addition to CO2).

The second means of ‘funding’ DAC is to use the captured CO2 as a basis for a ‘carbon neutral’ hydrocarbon or biologically-based fuel. Earlier in the thought process the idea was to create a hydrocarbon-based fuel, but that idea was complicated because such a process typically required high purity streams of CO2 and hydrogen (most sources of hydrogen are currently drawn from fossil fuel combustion). Now this idea has evolved into using CO2 as a highly concentrated feedstock for algae and extracting bio-fuel from the algae. However, the problem with this strategy is the same as using the CO2 for EOR, as long as the fuel produced by the algae is being consumed and the end-products released into the atmosphere, it is another closed CO2 neutral system over a legitimate CO2 negative system.

Again like with EOR due to the other externalities (infrastructure and transportation of inputs and outputs) involved the overall system should add CO2 and other greenhouse gases to the atmosphere. Also the fuel issue may be somewhat irrelevant as well because of the advent of electrical vehicles which could be powered in the future by electricity from trace emission sources (nuclear, solar, geothermal, etc.). If society did not have the technology required to transition away from fossil fuels to electrical vehicles for another couple of decades such a carbon neutral fuel idea may make more sense, but that is not the case. Thus, such a closed loop carbon neutral system seems to have no real benefit and only results in wasted energy and resources.

The waste is especially pertinent to trace emission energy generation if that generation comes from either wind or solar due to limited economically available amounts of various rare earths. Basically if only a certain number of solar panels could be created then there is no reason to waste any by attaching them to a closed-loop system which provides no significant net benefit. The same argument can be made for water as current DAC designs demand significant water consumption. Other ideas surrounding funding are generally small potatoes like selling the captured CO2 to beverage companies. Clearly there is a market for pure CO2 to beverage companies, but not a 7-gigatons of CO2 per year market.

So if there is no viable market for captured CO2 that is also in accordance to the principle reason for establishing a DAC network, then what is economic argument? The response is adjusting how one looks at the economic issue. The economics of DAC is not profitability, but prevention. For example does Person A eat broccoli on a regular basis because Person B pays them a sum of money to do so? No, Person A either consumes broccoli because they like it or because it is a healthy food. For the latter rationality there is reason to believe that the consistent consumption of broccoli will result in a reduced probability of various diseases and ailments in the future relative to a person who does not consume broccoli (all other elements being accounted for). Thus, the economic benefit for consuming broccoli is derived from lower future costs associated with healthcare and perhaps a reduction in lost wages due to less work missed versus immediate short-term incentive/reward.

No reasonable person disputes the fact that global warming will increase the probability and severity of future extreme weather events and will also change general weather patterns which will result in environments receiving much more or much less rainfall leading to an increased probability of flooding or drought (among other damage more notably from increases in temperature). After simply looking at the overall economic damage associated with extreme weather events along with floods/droughts in 2010 and 2011 alone a reasonable person would come to the conclusion that it is important to lessen the probability impacts of global warming as much as possible.

Also such a reduction would result in the savings of billions of dollars in the short-term (10-20 years from now) and trillions of dollars in the long-term (20-50 years from now). Therefore, similar to the broccoli example, the above prevention model is how proponents of the DAC should sell their technology instead of trying to make it short-term profitable. The profitability comes from the money saved in the future by reducing the probability of detrimental outcomes associated with global warming.

Based on this mindset proponents and designers of DAC systems should not be looking towards venture capitalists to fund the development and deployment of DAC systems as acquiring the necessary funds (billions of dollars) will be nearly impossible, unless said venture capitalists are young and have large stock holdings in insurance companies. In a just world every major company in the world would have to pay into a ‘carbon remediation and mitigation’ fund as a consequence to their past actions resulting in a significant percentage of the total amount of human-derived CO2 emitted in the atmosphere. Money from this fund could then be used to reduce human-derived emissions as well as fund DAC.

Unfortunately it is quite obvious that the world is not just; therefore, the argument of self-preservation must be applied and governments must bear the burden of development, a difficult reality due to the general financial crisis that currently exists. From a self-preservation standpoint China and India probably should be first in line with funding because both countries are high on the list of ‘going to have their environments significantly and detrimentally changed due to global warming’, costing them trillions in future economic damages.

Overall the whole point of pursuing DAC is to reduce the probability of detrimental effects from global warming by reducing the amount of CO2 in the atmosphere as fast as possible. The speed requirement limits the argument for planting new trees (although this still should be done). The sheer amount of CO2 that needs to be removed from the atmosphere is tremendous, so much that no CO2 market could be created to absorb anywhere near the amount that needs to be removed. So those looking to try to justify developing DAC under a ‘money in the pocket now’ economic model should fail unless one abandons the point of pursuing DAC in the first place, which then calls into question why one pursues DAC at all. Therefore, proponents must argue not from a viewpoint of how the captured CO2 will be utilized, but from the viewpoint of how much money will be saved when embarking on the program vs. failing to do so.

Is Global Thermostat any different from GRT?

Some recent attention has been given to a new technology start-up firm called Global Thermostat (GT), which similar to GRT (Global Research Technologies, which is now apparently Kilimanjaro Energy) aims to establish a profitable business from drawing carbon dioxide (CO2) from the ambient air. GT's system differs from GRT’s system in that it uses waste heat produced by interconnected power plants to power an amine reaction system over using independent power generation with a sorbent reaction system. Regardless of the technique, similar to when GRT first hit the news, most media publications have ‘conveniently’ foregone the debate regarding how this strategy should be perused and instead just anointed it another potential tool in the fight for reducing carbon emissions. Sadly such naïve and ballyhooed intentions do a disservice to the potential legitimacy of the ambient air capture strategy.

While the first question asked of carbon emission remediation processes should be total potential rational annual impact (TPRAI) on carbon emissions, in the current environment with all environmental remediation and mitigation strategies the first question boils down to economics. TPRAI should be considered as the principle issue because it is highly probable that, similar to power generation, a piecemeal approach to carbon emission remediation will not be successful because of the necessary resource division that arises from the myriad of strategies that would comprise a piecemeal solution. It stands to reason that two or three principle remediation strategies should be used to reduce the severity of global warming with the remainder being used only in case of emergency. Despite all of the publicity surrounding reforestation and biochar, ambient air capture appears to have the most potential in reducing the probability of occurrence and the severity of detrimental events derived from global warming over a near-term (10-30 years) timeframe. However, for this potential to be attained an effective and accurate analysis of ambient air capture must be developed, something that start-up companies like GT and GRT are not doing.

The sizable remediation potential advantage of ambient air capture, especially in the GRT system, is its reduced primary resource dependency. With both biochar and reforestation land use becomes a significant limiting factor reducing the overall remediation potential. For example most of the numbers that biochar proponents throw around require reverting a large amount of land already occupied for food consumption or other reasons to swichgrass remediation farms. Realistically this requirement will and should never come to pass, thus while biochar and reforestation can provide non-trivial remediation elements with genuine commitment, competitive land use reduces its absolute level of remediation potential. The sorbent/amine reactant for ambient air capture can be recycled, in the proper design, eliminating the chief limiting factor because the energy required for the recycling element and other elements can be acquired through use of renewable energy sources or waste heat as proposed by GT.

However, the economic realities proposed by these corporations are rather silly. Both groups propose that ambient air capture can be made economical by reducing the current price of carbon capture from the hundreds of dollars per ton ($200-$500 based on what estimate one uses) to less than $100 per ton ($30 per ton is a figure commonly cited by Klaus Lackner). Of course no details are given to how this dramatic drop in price will be achieved. Without details one simply assumes the rationality is that the price drop will come from mass production scale-up; however, to anticipate such a dramatic price drop with a lack of use of exotic or rare minerals or lack of first generation manufacturing technology which are both lacking in these designs, is difficult.

Another means to make ambient air capture economical is sale of the capture CO2. Some of the ideas floated around are use in soda and other carbonated products, aiding oil extraction, and use in the development of synthetic fuels, etc. Outside of aiding oil extraction the other ideas have little growth potential despite the incredibly optimistic beliefs of air capture proponents.

The best way to view ambient air capture is as a preventative measure designed to reduce future costs over actually being an economically self-sustaining entity. For example think of ambient air capture like a gym membership. Typically a person does not get paid money in the present term for going to the gym. The purpose of a gym membership (beyond issues of vanity) is it is a tool that is used to improve overall health, which reduces the probability that an individual spends money in the future on medical care due to poor health like high-blood pressure, high cholesterol, high tri-glycerides, etc. So while in the present owning a gym membership results in near-term debt (the cost of the gym membership) the inherent end design is future profit due to reduced future costs brought on by health related problems. Note that this future profit potential is not guaranteed, but is instead a probability-based arrangement.

The same goes for ambient air capture; the belief that ambient air capture will ever be near-term profitable is rather unrealistic and potentially dangerous. If too much importance is placed on near-term profitability then groups may not pursue the expansion and deployment of ambient air capture, which as discussed above, eliminates the remediation methodology with the most realistic carbon absorption potential. Returning to the gym membership example, owning a gym membership is almost analogous to a sunk cost if an individual only goes to the gym once or twice every month; no genuine health benefit can be derived from such little exercise.

Similarly if only a few ambient air capture units are constructed the effort is basically wasted. That reality is why the shift needs to be made away from near-term profitability because while one may find buyers for the first 50-100 million tons of CO2 collected every year, what about the other 1-2 billion tons of CO2? On a side note if humans are not going to fully tap the remediation potential of ambient air capture there is no point in further pursuing the technology. If humans cannot escape the near-term profit mindset and substitute a long-term profit cost reduction mindset then any serious mitigation and remediation strategy will struggle for acceptance, which will lead to much more difficult living conditions for the human species as the decades advance.

Another glaring problem with ambient air capture is a lack of specifics. This blog has already discussed the how the lack of specifics strip the legitimacy of GRT here. How does GT fair in specifics? The initial answer is not well. While there is an understanding of the need to protect proprietary information, the information provided by GT does not even reach a point where the need to shield proprietary information becomes a concern. For example here are the selling points that GT uses to demonstrate the worthiness of their idea (from their website):

Unique benefits of GT's Technology [Comment to the Point]

• Based on known and proven processes [This point is accurate;]
• Unique use of readily available surplus process heat [While true, describing the process as unique is a reach; a disingenuous use of technicalities to attempt to make the idea seem more creative than it actually is;]
• Makes carbon negative technology possible [True, but the word ‘possible’ implies that only this system can generate a carbon negative attribute, which is inaccurate and disingenuous;]
• Uses existing technology with most equipment off the shelf [Reiterating point 1 with different words;]
• Completely modular design allows greater flexibility and scale [Reiterating point 1 with another set of different words;]
• Economically viable process for capturing CO2 from ambient air [Really, where is the technical data validating this claim? Not on the website;]
• Offsets emissions from non-point sources such as transportation [Yes, but will transport of the amine base responsible for the absorption of the CO2 counteract this ‘advantage’?]
• Increases energy supplies while simultaneously reducing CO2 emissions [A rather vague statement. Assumption is that energy supplies will increase due to unrestricted power plant construction due to lessening of CO2 emission accumulation fears;]
• Ultimate flexibility in location requiring only heat and air [Again too vague because there are a number of required elements beyond just heat and air in amine absorption;]

Not surprisingly the individuals at GT seem more interesting in hyping their process than actually demonstrating its legitimacy as the superior process among those representing its competition. Sadly no serious discussion, on GT's website or anywhere else for that matter, has been conducted regarding the two most important elements of ambient carbon capture: water use and sequestration of the captured carbon. Until these issues are at least addressed relative to the proposed methodology any individual or group advertising ambient air capture as a solution should be viewed with significant scepticism. As the old saying goes, ‘The ball is in your court GRT and GT'. Note still no technical details from GRT/Kilimanjaro Energy.

Changing the Strategy – Planning for the Future

In the past months, including at the COP15 at Copenhagen, a large number of individuals have called for a scale of mitigation and remediation in global emissions of CO2 that would rapidly reduce the atmospheric concentration to at least 350 ppm. The target of 350 was selected, in part but not entirely due to the findings of Hansen et Al.1 which considered the current influence of climate forcings and what climate changes could be adapted to by human civilization at reasonable financial and human costs. Other goals have been proposed for 450 ppm where it is believed that average global temperature would not exceed 2 degrees C, which allows maintenance of a generally stable human society with proper adaptation strategies. However, the 350 camp adamantly believes that stabilization at 450 ppm would not be tenable to the comfortable survival of the human species on Earth, thus although 450 ppm would be acceptable for a very brief period of time, 350 ppm must be the plateau for a final CO2 atmospheric concentration.

Depending on what measurements one uses, the current atmospheric concentration of CO2 resides between 386-388 ppm.1,2 Unfortunately most proponents of the 350 movement fail to realize that this number represents CO2 concentration and its resultant climate forcing and not any of the other greenhouse gases which can be measured in CO2 equivalency. The atmospheric concentration for CO2 equivalency ranges even higher with a very high likelihood of being in the low to mid 400 ppm. Overall the 350 ppm goal must involve CO2 equivalency and not just CO2 alone otherwise the goal is structured in a way where direct achievement may not result in principled success.

Now one may find fault with the statement that CO2 equivalency is over 400 ppm, so how was that statement derived? The IPCC uses the following formula to calculate CO2 equivalency:

Total Climate Forcing = 5.35 ln(CO2 equivalency / CO2 pre-industrial);

First, note that CO2 pre-industrial is equal to the atmospheric CO2 concentration before humans began emitting large amounts into the atmosphere due to advances from the industrial revolution and beyond; this concentration is commonly viewed as 278-280 ppm.1 Most people view total climate forcing as the forcing from all significant greenhouse gases, significant greenhouse gases are defined by the Kyoto Treaty (CO2, CH4, N2O, HFCs and CFCs etc.).

Using these elements alone a total climate forcing relative to 2007 of approximately 2.71 W/m^2 can be calculated. This value leads to a CO2 equivalency of approximately 461.35 ppm to 464.67 ppm. However, this methodology does not take into account the fact that there are other forcings in the atmosphere as well which influence the climate such as areosols, surface albedo, clouds and ozone. In 2007 when the IPCC 4th Assessment Report was released due to a filing deadline it used empirical information from 2006 and earlier. This information generated a forcing map that defined a total climate forcing of approximately 1.6-1.7 W/m^2 when taking all relevant factors into consideration. The figure below outlines these forcings.3

These climate forcing numbers result in a CO2 equivalency of approximately 374.9 ppm to 382 ppm (very similar to the concentration of atmospheric CO2 at the time). The new CO2 equivalency numbers drop significantly due to the inclusion of the negative forcing influence assigned to aerosols, clouds and surface albedo among other elements. Unfortunately since the publication of the 2007 IPCC report new empirical evidence has re-evaluated the forcing influence of aerosols calculating a lower than previously thought negative climate forcing.4 Also new information has been discovered regarding clouds and the sustainability of their impact on climate forcing. Similar to aerosols, clouds provide a negative climate forcing which reduces the overall rate of increase in surface temperatures; however, this new information suggests that as sea surface temperatures increase low-level stratiform clouds decrease in both size and frequency.5 Thus the influence of clouds at reducing the severity of climate change is reduced as temperatures increase, so the influence of clouds will significantly wane over time.

In addition to the loss of influence from aerosols and clouds, surface albedo both on land and on sea, especially sea, have been taking a beating in recent years reducing their influence on limiting the rate of climate change. Finally logical intuition when viewing current empirical evidence suggests a higher atmospheric CO2 equivalency than a value equal to the current atmospheric CO2 concentration. For example the rate of ice melt in the Arctic, Greenland, Western and even Eastern Antarctica significantly eclipse the predictions made in the IPCC 4th Assessment Report, which suggests either incorrect assumptions regarding climate forcing or the exclusion of a significant factor influencing climate change in a negative (temperature increasing) way. With the size of most of the error bar associated with previous climate forcing calculations, the first option seems more probable. Overall with such rapid and negative changes to the climate everyone better hope beyond hope that CO2 equivalency is in the 400s and not the 300s, otherwise the situation is much worse than anyone previously thought.

With all this said there are a number of people that believe the target of 350 ppm is unrealistic in that humans do not possess the necessary tools and/or determination to accomplish such a goal and that humans are better off preparing for a world that has a greater average temperature of at least 2 degrees C. Proponents counter with claims that a phase out of coal in the next 20 years and aggressive anti-deforestation and reforestation programs would go a long way to reaching the 350 goal at modest costs. Unfortunately for the 350 ppm proponents the real failure in achieving maintenance of a familiar ecosystem and environment may not come from a failure in human will, but instead a failure in tactics based on inaccurate information. The chief concern is that improper tactics are being suggested to reach a goal due to incomplete information based on the warming trend.

There are two crucial elements pertaining to the probability of achieving a specific ceiling and stabilization of global surface temperatures: the climate sensitivity of the Earth and the atmospheric concentration of CO2 and other greenhouse gases. Climate sensitivity describes how the surface temperature changes in response to a stabilized doubling of atmospheric CO2. The reason climate sensitivity is important is it tries to provide a direct correlation between surface temperature and changes in CO2 concentration. Basically climate sensitivity describes the influence of greenhouse gases on temperature change. In 2007 the IPCC 4th Assessment Report defined the range of climate sensitivity between 2 and 4.5 degrees C.3 For 350 and other temperature ceiling movements such a range should be troubling because the lower range was raised by 0.5 degrees C from the IPCC 3rd Assessment in 2005 which defined climate sensitivity between 1.5 and 4.5 degrees C,3 in only a few years the estimated lower floor jumped 33%.

The primary means of deducing climate sensitivity is correlating known temperature change trends in the past with changes in atmospheric CO2 concentrations. The best historical data comes from the Last Glacial Maximum because of the size and accuracy of the temperature and CO2 concentration shifts. For example during the Last Glacial Maximum CO2 concentration where approximately 180 ppm vs. 280 ppm for typical pre-industrial times and the 386-388 ppm that current exist.6 Average surface temperatures dropped 7 degrees C in relation to this CO2 concentration which generated a climate sensitivity of 11.2 degrees C.6 Despite this number most climatologists consider it flawed due to questions surrounding how feedbacks like existing sea ice, clouds and water vapor with other particulates were factored in its calculation. Most believe that these feedback elements were more pronounced during the Last Glacial Maximum then they are now which significantly reduces climate sensitivity in the present.

Overall the most widely accepted value for climate sensitivity comes from Charney who calculated a climate sensitivity of 3 degrees C when incorporating fast feedbacks.7 Unfortunately this calculation assumed an instantaneous doubling in CO2 with no surface changes. Eliminating any surface changes limited the accuracy of the calculation. Hansen et Al.1 used paleoclimate data when including slow surface albedo feedback while assuming a first order relationship for the area of surface/sea ice as a function of global temperature to calculate a climate sensitivity of approximately double Charney’s calculation (6 degrees C vs. 3 degrees C). Normally such a calculation would not be a huge deal because slow feedbacks operate over centuries to millennium, but these operational ranges were only experienced through natural cycles, not with humans dumping hundreds of gigatons of CO2 into the atmosphere. Thus, it is difficult to rule out these slower feedbacks exerting an influence after decades instead of centuries. Empirical evidence especially demonstrates significance for these slower feedbacks because of the rapidly melting surface ice in the Arctic.

Determining a reasonable climate sensitivity is important because it is a principle element in how predictions are made regarding future changes in surface temperature and the overall climate in general. The principle elements that allow predictions on the future climate come from many different climate models and current empirical observations. Modeling the climate is incredibly complicated requiring thousands of different variables as well as the inclusion of hundreds to thousands of interactions between those variables to generate results that can even only be considered ‘in-the-ballpark’. The application of these interactions and variables creates a tremendous demand on time and energy for the computers involved in the modeling. Therefore, to ensure that the generation of a single result does not take weeks/months, certain elements are removed from consideration in the final results. In addition there are some gaps in knowledge regarding how certain variables interact with other variables and in an attempt to ensure some level of accuracy, these types of interactions are also removed or estimated as best as one can and modeled accordingly.

Unfortunately these omissions create inaccuracy in the ability of the model to predict how the climate will change relative to how it actually changes. It is in these omissions where most climate skeptics have attacked with the claim that because x model is potentially inaccurate then the very essence of climate change is wrong. Of course any rational person realizes that such claims are utter nonsense as all of the valid empirical evidence still demonstrates that climate change is occurring almost entirely due to the actions of humans and the lack of a completely accurate model, something that probably will never be generated in the first place, does nothing to taint that evidence. However, in the past few people have considered that the predictions made by climate models were incorrect on the other side of the coin, that they are underestimating the rate of climate change. Due to new empirical evidence, largely surrounding the much more rapid ice and glacier melt in the Arctic,8 more individuals are questioning whether the results of the 4th Annual IPCC report were inaccurate, predicting too slow of a surface temperature shift.

When predicting future temperature changes climate models tend to generate either a linear or a quasi-exponential change in the increase in average global air temperature over future years. For example after modeling four distinct scenarios of human action for the future, the 4th Annual IPCC report illustrated surface temperature changes as shown in the graph below.3

At first glance such predictions may seem practical based largely on how much CO2 and other greenhouse gases humans continue to emit into the atmosphere through future action. However, when considering all of the potential environmental feedback elements that could trigger during warming such results seems less and less plausible. The more noteworthy feedback factors that have a high probability of playing a role in additional future temperature increase include: increased water evaporation leading to more water vapor in the atmosphere,9,10 CO2 and methane release from melting permafrost,11,12 nitrous oxide release from peat sources,13 increased ocean albedo due to Arctic ice melt,3 new cloud synthesis or disappearance at different altitudes,5,14 increased rainforest dry season reversing sink to source behavior,15,16 and increased ocean temperatures resulting in conversion from sink to source. Although all of the previously listed feedback elements demand concern, permafrost melt and ocean out-gassing demand the most concern due to the sheer amount of CO2 that either process could eventually release into the atmosphere. Both of these problems have previously been addressed on this blog at the following links:

Permafrost: http://bastionofreason.blogspot.com/2009/08/permafrost-and-carbon-stores.html

Ocean Out-Gassing: http://bastionofreason.blogspot.com/2009/09/ocean-acidity-danger-and-remediation.html

It must be noted that the IPCC report identifies the potential inaccuracy in its conclusions due to feedback processes that were not included in the modeling. The decision to exclude most of the feedback information seems to stem from the lack of conclusive and accurate empirical information pertaining to those feedback processes. Basically the mindset of ‘some inaccuracy by not including feedback process A is better than gross inaccuracy through interpreting the feedback process incorrectly.’

Even though the potential inaccuracy is discussed, sadly enough it appears that increased water vapor was the only significant one attempted with varied results.3 A discussion was also given regarding the potential reduction of land and oceanic sinks due to surface temperature increases, but no direct comments regarding sink to source transformation were made. The inaccuracy of the IPCC used models and some of its conclusions have become quite evident most notably in the rapid pace of ice melt in the Arctic and new conclusions that the Arctic may be completely free of summer ice by only 2015-2020 instead of 2080-2100. The most unfortunate element in all of this seems to be the fact that most climate proponents themselves do not incorporate the potential feedback elements into their strategies with regards to limiting surface temperature increases to a certain boundary ceiling. Overall with the inclusion of feedback elements future average global surface temperature increases will more than likely follow a more severe trend than shown in the above graph.

The assumption of a more severe trend in temperature warming finds support when one considers the influence of the ocean in the carbon cycle. In large respects the ocean can be viewed as a dynamic replenishing buffer of some sorts. Various denizens of the ocean, most notably phytoplankton, are able to absorb CO2 either directly from the atmosphere or in the ocean for photosynthesis. When these organisms die, the CO2 that was used in photosynthesis is typically confined to the bottom of the ocean in sediment. After confinement to sediment the capacity of the ocean to absorb CO2 increases. In short due to the interaction of oceanic organisms the ocean is able to continually and consistently increase or at least maintain its ability to draw CO2 from the atmosphere.

Unfortunately buffers can only neutralize pH changes to certain concentrations. When a counter-agent (acid or base) is added at a high enough concentration the buffer collapses and the pH shifts. Such is also true for the ocean and its ability to absorb CO2. As the concentration of CO2, largely due to human driven activities, increases the ocean continues to absorb that CO2, but the rate of absorption is faster than the action of the pathway responsible for burying CO2 in sediment. Thus, concentrations of CO2 in the ocean build-up both by reducing the ability of the ocean to absorb further CO2 from the atmosphere as well as decreasing the efficiency of the CO2 removal pathway by limiting the available organisms responsible for that CO2 removal. The number of organisms is limited due to increases in acidity which result in less available calcium carbonate for certain food chain critical organisms to construct calcium carbonate infrastructure. When these creatures, like coral, are unable to create calcium carbonate shells it negatively affects large portions of the oceanic food chain including organisms that aid in CO2 removal. Eventually this process will conclude at a concentration equilibrium point where the ocean will no longer be able to absorb CO2 from the atmosphere eliminating its CO2 sink capacity.

Now while the loss of the ocean as a sink is bad enough, there is a very real possibility that the ocean will eventually become a source for increasing atmospheric CO2 instead of a sink. Most of the warming due to the excess CO2 in the atmosphere has not occurred on land, but in the ocean. This warming is important because gas solubility in a liquid decreases as temperature increases because increasing temperature increases available kinetic energy which increases molecule movement. Greater molecule movement increases the probability of bond breaking which reduces the ability of the gas to remain in solution. Therefore, as the ocean continues to warm its maximum capacity for CO2 storage in a dynamic equilibrium with the atmosphere will decrease causing it to release CO2 into the atmosphere until it is able to establish a new lower storage equilibrium. Although it is unclear how much CO2 could be released as a result of a negative gas solubility shift in the ocean, the fact that the ocean has increased in CO2 concentration by 118 +- 19 gigatons in the last 200 years17 and absorbs approximately 8-10 gigatons of CO2 a year from the atmosphere paints a dreary picture. Overall although out-gassing would be horrible, the loss of the ocean as a CO2 sink would be far worse over the course of decades.

Tie in the feedback resultant loss of the ocean as a CO2 sink with the potential of out-gassing to the prospect of a continual release of CO2 and methane from the potential 1,672 gigatons of carbon storage load in permafrost18,19 and those two feedback elements alone could create a huge shift in surface temperatures regardless of what humans emit in the decades to come.

Suppose one rejects the above contention of rapid severe warming due to these feedback effects? Even if such warming is rejected and such a rejection turns out to be correct in reality, those wishing to hold temperature increases at a ceiling of 2 degrees C still have the problem of ‘backwash warming’, warming that has yet to catch up with the influence of the current level of climate forcings. Basically the amount of climate forcing that has currently been applied to the environment has not been fully compensated for through change in average surface temperature largely due to slow feedbacks. That is to say that if all human based CO2 emissions were ceased tomorrow, the average global temperature would still increase another x degrees. Although it is not clear how much actual warming will occur through this ‘backwash’, Hansen et Al.1 estimate an additional global temperature increase of approximately 1.4 degrees C. Add that increase to the current increase from pre-industrial times of 0.6 to 0.9 degrees C (depending on what track information is used) and an increase of 2 degrees C is extremely probable regardless of what actions humans take. The graph used by Hansen et Al.1 to illustrate this additional future warming is shown below.

However, regardless of these concerns there is still time to successfully derail significant climate change, but only if the proper strategy is taken. Although the hot topic, the more trendy and popular geo-engineering strategies are unlikely to prove useful in short-term because of two significant flaws. First, they do relatively little, if anything, to alter the concentration of CO2 in the atmosphere instead they work to mask some percentage of the warming driven by this CO2 concentration. Second, they do nothing to change the concentration of CO2 in the ocean, which maintains ocean acidity and limits the ability of the ocean to remove CO2 from the atmosphere. Therefore, if geo-engineering is to be utilized the strategy must attack one of these two issues otherwise it would lack usefulness. Strategies like reforestation or bio-char would be useful, but would also fall far short of drawing out the required CO2. Also it is unlikely that exportation of CO2 into the upper atmosphere and eventually space would prove useful or even viable.

Reduction or mitigation of future emissions is an important element for limiting the total amount of temperature increase, but it is clear that the governments of the world are unwilling to create the cuts that allow mitigation to be an independent strategy that lacks further technological intervention. Currently despite the cries and curses from the environmentalist moment, it is unlikely that enough viable trace/zero emission energy can be generated to compensate for the draw down from coal and natural gas at the speeds required. Also regardless of how some environmentalist spin it, like Joe Romm of Climateprogress, China issuing a non-binding pledge to reduce carbon intensity is rather meaningless because reducing carbon intensity (with the economic growth still to available for China) instead of doing nothing is like getting a 32% on a test instead of a 19%, it is still failure. As it currently stands if the required cuts to avoid significant increases in surface temperature (2-3 degrees C) were to be made it would be a significant detriment to the overall global economic output due to less available energy. The energy gap that is created through emission mitigation for the United States was previous discussed in detail here:

http://bastionofreason.blogspot.com/2009/07/emission-adherence-in-2020-and-2030.html

So if mitigation is not occurring rapidly enough and generic geo-engineering tactics are basically worthless, what is to be done? The principle action beyond mitigation must be to draw CO2 out of the atmosphere via technological means. Technology must be harnessed solely because natural methods are just not fast enough. Not only are current carbon sinks becoming compromised due to current warming,20 but it is highly unrealistic that enough trees can be planted in the near-future to enhance land sink capacity especially when REDD, the most promising anti-deforestation proposal, has yet to expand in any significant capacity. Soil strategies using various tilling methods or bio-char may increase sink capacity by very minute amounts, but nothing to the level that is required. Thus, technology must be used.

In short all research funds that individuals want direct towards point-source carbon capture (a.k.a. clean coal) must instead be directed to non-point-source carbon capture (a.k.a. air capture). This blog has previously discussed the outstanding concerns with air capture and they are significant, but realistically the only way humans stop an increase in average surface temperature of even 3 degrees C without a miracle occurring is a combination of reducing carbon emissions and some form of air capture. Finally the development of a technology that could draw CO2 from the ocean would be an exceptionally useful tool in furthering mitigation by increasing the sink capacity of the ocean.

Overall the environmentalist movement needs to shift gears; it is somewhat humorous in that its members vent frustration at the portrayal of the question of global warming like it is a legitimate debate, yet these same individuals do the same by continuing to talk to species annihilators (global warming deniers) in a context of trying to convince them. At this point in time the debate is over; anyone who believes that humans are not the driving force behind climate change will not change his/her opinion regardless of what facts and evidence are highlighted, it is not worth wasting more time trying to convince them. The only thing that will convince these individuals are negative climate events that directly affect them, nothing which can be provided by environmentalists. In addition further discussion and proposition of foolish and inefficient boycotts of high emitters bad guys like Exxon should cease because truly such a strategy would be ineffective and just take time away and personnel away from more meaningful and effective endeavors. Instead it is time to move into research and innovation mode.

Solutions and strategies need to be prepared for when they are needed in the future. An honest assessment of what energy technologies will be needed to replace coal and natural gas will need to be identified. Just a quick note for those wind supporters, wind will not even come close to providing the necessary energy for global growth or even growth in the United States, especially if wind speeds continue to fall. Is nuclear really that expensive, preventing its widespread adoption, or is the expense only contingent on using 2nd generation technology over 3rd or 4th generation? What new energy strategies will need to be researched? There are many more questions beyond the few mentioned above that demand discussion and attention. Also these discussions cannot be broad based with weak statements like ‘oh all sorts of trace emission energy sources like wind, solar, nuclear and geothermal will be needed for the future’. No, these discussions must be full of details and specifics, so businesses and researchers know exactly what the future markets demand and expect.

In the end although mitigation is important, remediation is also important because the environment has reached a point where nature cannot restore the balance on its own. There are important questions to be asked regarding remediation and it is time for the environmental movement to start focusing in on those questions rather than lamenting or championing the latest meaningless poll regarding the public’s view of global warming, clean energy or whatever else is the subject of the poll de jour.

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1. Hansen, James, et, al. “Target Atmospheric CO2: Where Should Humanity Aim?” The Open Atmospheric Science Journal, 2008, 2, 217-231.

2. Tans, Pieter. NOAA/ESRL (www.esrl.noaa.gov/gmd/ccgg/trends)

3. Climate Change 2007: Synthesis Report. Intergovernmental Panel on Climate Change.

4. Myhre, Gunnar. “Consistency Between Satellite-Derived and Modeled Estimates of the Direct Aerosol Effect.” Science. June 18, 2009. DOI: 10.1126/science.1174461.

5. Clement, Amy, Burgman, Robert, and Norris, Joel. "Observational and Model Evidence for Positive Low-Level Cloud Feedback." Science. July 24, 2009. 325: 460-464. DOI: 10.1126/science.1171255

6. Kohler, Peter, et, Al. “What caused Earth’s temperature variations during the last 800,000 years? Data-based evidence on radiative forcing and constraints on climate sensitivity.” Quaternary Science Reviews. 2009. 1–17. doi:10.1016/j.quascirev.2009.09.026

7. Charney J. “Carbon Dioxide and Climate: A Scientific Assessment.” National Academy of Sciences Press: Washington DC 1979. 33.

8. Hawkins, Richard, et, Al. “In Case of Emergency.” Climate Safety. Public Interest Research Centre. 2008.

9. Santer, B, et, Al. “Identification of human-induced changes in atmospheric moisture content.” PNAS. 2007. 104: 15248-15253.

10. Dessler, A, et, Al. “Water-vapor climate feedback inferred from climate fluctuations, 2003-2008.” Geophysical Research Letters. 2008. 35: L20704.

11. Åkerman, H, and Johansson, M. “Thawing permafrost and thicker active layers in sub-arctic Sweden.” Permafrost and Periglacial Processes. 2008. 19: 279-292.

12. Jin, H.-j, et, Al. “Changes in permafrost environments along the Qinghai-Tibet engineering corridor induced by anthropogenic activities and climate warming.” Cold Regions Science and Technology. 2008. 53: 317-333.

13. Dorrepaal, E. et, Al. “Carbon respiration from subsurface peat accelerated by climate warming in the subarctic.” Nature. 2009. 460: 616-619.

14. Booth, B, et, Al. “Global warming uncertainties due to carbon cycle feedbacks exceed those due to CO2 emissions.” Geophysical Research. 2009. 11: 4179.

15. Cook, K, and Vizy, E. “Effects of Twenty-First Century Climate Change on the Amazon Rain Forest.” Journal of Climate. 2008. 21: 542-560.

16. Phillips, O, et, Al. “Drought sensitivity of the Amazon rainforest.” Science. 2009. 323: 1344-1347.

17. Sabine, C, et, Al. “The Oceanic Sink for Anthropogenic CO2.” Science. 2004. 305: 367-371.

18. Schuur, E, et Al. “Vulnerability of permafrost carbon to climate change: Implications for the global carbon cycle.” BioScience. 2008. 58: 701-714.

19. Tarnocai, C, et Al. “Soil organic carbon pools in the northern circumpolar permafrost region.” Global Biogeochemical Cycles. 2009. 23: GB2023.

20. Canadell, J, et, Al. “Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks.” PNAS. 2007. 104: 18866-18870.

Air Capture Update – Is GRT’s Air Capture Device Viable?

Back in the July this blog wrote a detailed post about why the development of certain technological strategies to work in consort with emission reduction would be necessary to ward off significant climate change.

That post can be found here: http://bastionofreason.blogspot.com/2009/07/turning-clock-back-reducing-atmospheric.html

One of the more promising technologies was air capture, which involves capturing already emitted atmospheric CO2 instead of focusing on newly emitted CO2 for power plants. However, neither the system proposed by David Keith or Frank Zeman appeared to be cost effective and the system that Global Research Technologies (GRT) has proposed under the guidance of Klaus Lackner is still quite mysterious when it comes to the kinetics and costs.

Interestingly perhaps some light can now be shed on the GRT system in that in a recent interview with the Columbia University school newspaper, the Columbia Daily Spectator, (note that this interview has been recently taken down and appears to be no longer available) Mr. Lackner is reported to have said regarding the GRT device: “And even with current ‘dirty’ electricity, these machines are 80 percent efficient: Only 20 percent of what they sequester is cancelled out by their electricity use.”1 By knowing the efficiency of the device a cost per net ton of CO2 removed can be calculated. Also note that it is highly probable that Mr. Lackner misspoke in that statement in that the CO2 is not technically sequestered, but simply absorbed by the air capture device. This post is assuming that long-term sequestration of the absorbed CO2 typically within underground rock formations is not included in the efficiency calculation.

First, it is appropriate to assume that the current electrical grid, which is comprised of a balanced mix of electricity sources, is being used to power the device. As is typical 2007 grid percentages will be utilized in the analysis, for 2008 and 2009 data are not accurate assessments due to the recession. In 2007 coal made up 48.97% of the grid and produces approximately 1 ton of CO2 per MW-h generated;2 natural gas made up 20.08% of the grid and produces approximately 0.4 tons of CO2 per MW-h generated (when burned at maximum efficiency);2 petroleum made up 1.58% of the grid and produces approximately 0.75 tons of CO2 per MW-h;2 the rest of the grid can be assumed to be made up of trace/zero emission sources (nuclear, hydroelectric, wind, biomass and solar). Taking these elements into account it can be determined that electricity provided from the grid on average will produce 0.8594 kW-h of electricity/lb of CO2 emitted into the atmosphere. Knowing that the efficiency of the system is 80% the total amount of kW-h of electricity required to capture 1 gross ton of CO2 can be calculated at 0.17188 kW-h/lb of CO2.

Second, assume the same price on electricity per kW-h as was previously assumed in the sequestering post (9.1 cents). Knowing the system capture energy requirement, efficiency and the cost of electricity, a cost per ton of CO2 can be calculated → 0.091 dollars/kW-h * 0.17188 kW-h/lb of CO2 captured * 2000 lb/ton = $31.28 per gross ton CO2 captured. Of course that value is only the gross value, efficiency must be inserted into the equation to calculate the net value of $39.10 per net ton of CO2 capture. Based on these calculations it appears that GRT’s device is much better than the devices proposed by both David Keith and Frank Zeman.

However, although it seems better there are a variety of issues that remain regarding this value. First, just from a physics standpoint the above calculation seems very suspect. If accurate the GRT system only requires about 60 kJ to capture 1 mole of CO2. Without actual scientific documentation, heck even with it, it is extremely difficult to take that value seriously. Also the calculated value is already significantly lower than the $100 per ton of CO2 value that is frequently cited by GRT for the operation of their device, which does not make any sense.3

Second, regarding the above issue, there still appear to be no scientific publications on the device that GRT proposes, thus there is no genuine information regarding its abilities and capacities outside of the sound-bite blurbs that GRT representatives, most notably Mr. Lackner, give to the press like the above efficiency number. This lack of empirical evidence regarding how efficient and effective the device is leads to continued questioning and concern about the actual abilities of the GRT device. If the resin used in the device is proprietary and prototypes have already been tested where efficiency numbers can be declared then it naturally seems suspicious that no publications regarding the device have surfaced, at least where one could find them through conventional means.

Third, there is still a lack of information pertaining to the amount of water used per net ton of CO2 absorbed. The water question is critical because as discussed in the sequestering post, it is highly probable that the world will face significant water shortages in the near future and having to use millions to billions of gallons of water in air capture for a reduction of just 1 ppm could very well sink air capture as a viable remediation technology. Based on the limited information regarding the functionality of the GRT absorption resin it definitely appears to require water to function properly; however, there is no information regarding how much is required.

Fourth, the passive transport system is an attribute of the GRT device that may cause serious viability problems. Based on press releases and discussions with the press,3 it appears that the device as it is currently structured can absorb 1 ton of CO2 per day or 365 tons of CO2 per year if average day capacity is maintained throughout the year. This value is dreadfully small, for it would require approximately 21,370,000 devices to remove only 1 ppm from the atmosphere in a given year. Although it is reasonable to assume that the absorption value will increase with scale-up it is unlikely that the overall value using passive transport will exceed an average of 3 tons per day (1095 tons per year or 7,123,334 devices for 1 ppm per year).

Currently initial capital construction costs are estimated at $200,0001 (which means it will probably end up costing more). In the future Mr. Lackner believes that these costs will scale down to $20,000,1 but that seems unlikely; realistically $100,000 is probably as cheap as these devices will go. Splitting the difference half at $200,000 and half at $100,000, it would currently cost 1.0685 trillion dollars [in just initial capital costs not including maintenance or operational costs (note that operational costs are the real killer)] to construct the number of devices necessary to achieve a 1 ppm per year reduction at a 3 tons of CO2 per day absorption rate.

Overall it seems highly unlikely that anyone or government would invest such capital in a device that generated such small returns, especially without any viable long-term market for the capture CO2 (as discussed in the sequestering post). Mr. Lackner likes to use automobile production as an example to justify his future cost-estimates and the will of the public to invest in air capture, but such reasoning is seriously flawed because of the aforementioned lack of a long-term market for captured CO2. It is troubling that Mr. Lackner believes that the soft drink, oil and sanding equipment industries will provide viable markets that will be able purchase gigatons of CO2 annually.

Therefore, an active transport system needs to be utilized, even though such an addition would increase energy required to absorb CO2, which would increase the cost to absorb CO2, but such a cost increase is necessary if significant climate change is to be avoided. Recall that the primary advantage of air capture over simply planting trees is speed, an attribute the GRT system does not maximize. Without an active transport system, which literally sucks air into the system, it almost seems more rational to simply plant a bunch of trees than bother building an air capture network.

The more information available the better when it comes to evaluating where the government and private investors should put their money. Air capture might be the only real hope for humanity when it comes to avoid detrimental climate change. Unfortunately there appear to be a significant number of problems with the system proposed by GRT even despite the lack of available information. Note that the technical literature section of their website is still coming soon.

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1. Columbia Newspaper Article; [Although the article no longer appears to be available a copy of text was made before it was taken down and is posted below]

2. “Electric Power Industry 2007: Year in Review.” Table ES1. Summary Statistics for the United States, 1996 through 2007. Energy Information Administration. May 2008.

3. Various Press-Releases and News Articles from GRT Wesite: http://www.grtaircapture.com/

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Columbia geophysics professor Klaus Lackner is building a device that can take carbon right out of the air. The machine, which is often described as looking like “a goal-post with Venetian blinds,” counteracts climate change in the same way trees do: by collecting carbon to keep it out of the atmosphere. But his devices are 100 times better at it and could address climate change without disrupting infrastructure, industry, or productivity. Lackner claims that “with the best technology currently available, I can get about a ton a day, maybe a little more, with a unit that can fit in a standard shipping container.”

These air capture devices could also be set up anywhere—from Antarctica to the Sahara. It doesn’t matter because, as Lackner points out: “You can have a car in San Francisco producing CO2 and a collector in the desert of Australia taking it back. It’s all the same CO2.” Once the machines are set up and plugged in (they do require some electricity) they are essentially passive, just collecting carbon dioxide as air flows across their “blinds,” which are strips of a special material developed by Lackner and his colleagues for grabbing CO2. And even with current “dirty” electricity, these machines are 80 percent efficient: Only 20 percent of what they sequester is cancelled out by their electricity use.

After they collect the carbon, Lackner and his team can go in one of two directions. They can either incorporate the CO2 into stable carbonates and bury it in the ground, or they can combine it with water to make synthesis gas: the precursor to synthetic gasoline and oil. This solution is especially promising because it could create a closed cycle of energy in which carbon dioxide is captured and re-emitted with no net increase in harmful greenhouse gasses.

Of course, one machine tree isn’t enough. We would need a million of them to mitigate climate change and up to 10 million to return to pre-industrial carbon levels. Surprisingly, this is feasible. As with cars, building just one air capture device would be extremely expensive, but mass-producing them in a streamlined system is 10 times cheaper. “To put that in perspective,” Lackner says, “the world produced 73 million cars in 2006 … so several million air capture units is not unreasonable.” “And,” he adds, “we clearly have enough room to park 10 million cars.”

Lackner is currently raising money to construct a full-scale prototype of his air capture device, which he estimates will cost about $200,000. Though this seems a high price, Lackner is confident that it will eventually fall to car-level: about $20,000. “We could actually collect carbon without ruining the world economy or changing how things are done,” he says. “With 3 or 4 factories, we’d be in the game.”

The air capture industry could also scale up just as the automobile industry did—starting out with small niche markets and higher prices and then, as manufacturing becomes more efficient, lowering costs and expanding into wider and wider markets. There are, in fact, a number of industries, including soft drink production and sanding equipment manufacturing, that must purchase large quantities of concentrated carbon dioxide to produce their goods. “That gives us a leg up,” says Lackner. “We can start with a few tons of CO2 in one location, and as we gain experience we can build more units that are cheaper, and our potential market will get larger.”

Air capture is unlike other climate solutions in that it addresses the problem directly and won’t require an overhaul of infrastructure or policy. Switching to electric cars, for example, would require a completely new and highly convenient refueling system, and would have a huge impact on trade and trade relations. Because Lackner’s devices are modular and can be installed anywhere, they don’t require that we develop a new transportation system or change the way we do things. Also, air capture is an ideal fit for the cap-and-trade system already in place because it collects carbon in a precisely quantifiable way.

When asked about his efforts to generate political interest for his work, Lackner laughs, “Well, we’re talking about it right?” It takes time to convince people that a technology is real and viable, he says, and it takes time to convince people it has policy implications. “It [climate change] also has to hurt before people will act, and we could well be too late by that time.”

Still, Lackner sees a bright future for climate and energy research. “Business as usual manifestly does not work, but we desperately need the energy,” he says. “So to me, this is one of the most exciting fields to be involved in.” A solution to climate change is about more than just science—it’s about economics and politics as well. “This field will not succeed,” he says, “unless it combines the restraints of all fields into one way to think about the problem.”