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Tim Werner

After reading about suspended particulate matter and its effect on human health earlier this week, I found this article very interesting because it further investigates the effects of black carbon, specifically on climate change. New estimates reveal that black carbon’s heat-trapping capacity is about 1.1 watts, which is second only to Carbon dioxide and substantially greater than estimates made in 2007. However, the role of black carbon in global climate change is very complex. Since black carbon has both warming and cooling effects in the atmosphere, it is difficult to determine the net effect of its emission. Although black carbon quickly washes out of the atmosphere, it can still have effects afterwards on ice by absorbing heat and melting ice and reducing the ice’s ability to reflect sunlight; some of the carbon from the emissions lingers in the atmosphere longer than the soot, and therefore continues to absorb heat.

Before the new study that revealed black carbon’s heat-trapping capacity, scientists had already developed technology that could be used to reduce emissions from coal-fired plants and stoves. The new findings that black carbon is second only to carbon dioxide in heat-trapping capacity should encourage people to reduce emissions and utilize the cleaner technology, if they have any concern for global climate change. As a complement to the previous article on health effects of suspended particulate matter, this article presents more convincing evidence to reduce future black carbon emissions by addressing its effect on global climate change.

Holley Beasley

Carl Zimmer gives insight into the complexities of solving the global warming issue. While all scientists can agree on the existence of global warming and of its detrimental effects, they are still working to figure out what type of pollution exactly is causing it and determine the full spectrum of effects each type of pollution has on the environment. So scientists are trying to educate the public on a topic that they, themselves, are still learning about. But that is exactly what they need to be doing, because we can't wait for them to completely eliminate their margin of error on their results. We need to act now, by encouraging the installment of stoves that release less black carbon into peoples' homes with subsidies and by increasing the tax on diesel.

One thing I was a little confused about is that Zimmer says we need to be careful and target the black carbon we eliminate, because some of it is good. While that may be true, most of it is bad, so I think it should be worth eliminating that little bit of good in order to get rid of a whole lot of bad.

Doug Poetzsch

Putting this in a framework we talked about in class, Zimmer seems to be arguing that the marginal damage from certain types of black carbon emissions is much higher than the marginal abatement costs. Diesel fuel and dirty coal burning are two examples where Zimmer thinks soot emissions are doing the least good and the most bad for global climate change. Since in these two areas marginal damages are greater than marginal abatement costs, it would make economic sense for us to reduce our emissions of black carbon through diesel and coal sources until marginal damages equal marginal abatement costs.

Still the confidence interval for the real impact of black carbon is very wide. It appears as if more research needs to be done before a conclusive result can be formed. Still, if black carbon does have as big of an impact on climate change as this study suggests, than perhaps by eliminating it we can slow down the earth's warming process and avoid the high end (5 degrees Celsius) of the range projected to take place in the next century.

Emily Foggo

This article claims that black carbon soot is responsible for 1.1 watts per square meter of the energy that is trapped on earth and contributing to global warming. This statistic places black carbon soot second only to carbon dioxide emissions, which are responsible for 1.56 watts per square meter of the energy trapped within the atmosphere. While this statistic is staggering, I think it is critically important to address the confidence interval with which it comes. In 2009, Doherty and her colleagues stated they were 90% confident that the effect of black carbon soot on the environment was between .17 and 2.1 watts per square meter of energy. From an econometric standpoint, this confidence interval is huge. If black carbon soot were only responsible for .17 watts per square meter of the energy contributing to global warming, then it would only have 10% of the effect that carbon dioxide emissions have. If, however, black carbon soot were responsible for 2.1 watts per square meter of energy, then it would have 130% of the effect of carbon dioxide emissions. This range is simply way too large for me to trust, particularly at a 90% confidence level.

With that being said, I still believe it should be a priority to reduce our black carbon soot emissions as much as needed. Until scientists perform further studies, we may not know exactly how dangerous soot really is in the environment, but that does not mean we should ignore the effects completely. We now know soot is not only hazardous to human health but it is also, to a certain degree, hazardous to planetary health. So, regardless of the strength of the effect, we should invest in efforts to reduce emissions now and worry about pinpointing the exact effects later.

Courtney Ridenhour

Doherty’s study further reinforces that what we face isn’t entirely a consumption problem. As we discussed in class, we face a coal problem. With an estimated 400+ years of coal reserves, and energy use in developing countries is predicted to increase fivefold, coal poses a greater problem. The new information on the damage costs of black carbon further this point.

The study found coal is a “potent source of warming from soot.” A forest fire produces black carbon and organic carbon molecules – the latter offsets the warming from the former. This is not the case for burning coal. There is no counterbalancing effect, driving the costs only higher.

Paul R

This article was interesting in the fact it explained how black carbon works. I have heard of carbon dioxide but black carbon doesn't seem to be publicized as much. Black carbon being washed out of the atmosphere seems interesting. In terms of the atmosphere it sounds easier to correct. We have atmospheric chemicals that are used to make rain occur over forest fires. This might be one interesting way of clearing out the atmosphere. Similarly to the particle matter and fine pms we learned about in class. Carbon dioxide is not the only impact on the environment and should be taken into consideration in our cost curve. Unfortunately similarly to carbon dioxide it is found naturally through forest fires which actually can help the environment through clearing room for new species which otherwise wouldn't be able to thrive.
As a side note I thought we had a wood burning energy source on campus. Would be interested to know if anyone else knows anything about this. Would be an interesting study to see how much black carbon it produces per school semester.
_Paul Reilly

Shawn Swaney

Emily, I'm glad you brought up the statistics, as it was a part of the article that my attention was drawn to upon reading. The range of watts/square meter is so large, especially when you consider that carbon dioxide emissions (something that society and scientists deem as prevalent) are listed at 1.56 W/sq meter. This signals to me that "black carbon" is an area that needs to be looked into further. It shows promise that a team of 31 scientists were solely focused on this topic.

In the future, further evaluation of soot emissions and taking advantage of its inevitability could prove incredibly useful. When you think of issues like rising sea level, I often think that it is an inevitable consequence of global climate change. Nw being able to look at the positive effects of soot in the atmosphere, I have confidence that there is a feasible way to slow the rising sea level.

Hampton Ike

This article addresses an interesting and complex element of emissions and atmospheric pollution. The piece we read earlier last week regarding the ultra-fine particulates and their role in around half a million deaths was stunning. The effects of "black carbon" are certainly visible as was evident in the Beijing Olympics, when athletes withdrew or wore masks around the city to prevent any encounter with the heavy pollution. I do have to disagree with the article with respect to placing black carbon as the second most influential form of pollution behind CO2.
Firstly, carbon dioxide remains in the atmosphere for upwards of four hundred years, constantly heating the earth the entire time. The black carbon particulates according to the author do not remain in the atmosphere very long, though they do reduce albedo of arctic landscapes when they mix with precipitation. I certainly agree that black carbon emissions should be reduced, but I think he grossly overestimates the marginal damage function with respect to the soot. Furthermore, the watt per meter squared statistic that he presented of 1.1 for black carbon was a very rough estimate. What I mean by rough estimate is that, he presented a 90% confidence that ranged drastically from above CO2 at 2.1 too well below other factors of pollution at .17. I think that before addressing the black carbon problem with any explicit and specific legislation a much more accurate study regarding the impact of black carbon must be done. I am not saying that nothing should be done, but I think the focus currently should be on reducing well known greenhouse gas emissions as well as ultra fine particulates and other such documented and well understood sources of climate change.

Chris Nault

The study that this article revolves around is a very important discovery that will enhance how we treat climate change and the ways in which we can help to slow climate change. This article shows that scientists now know the major effects that soot, or black carbon, has on global warming, with some of the effects enhancing warming and some causing atmospheric cooling. What I believe to be one of the most important issues discussed in this article is the complexity surrounding black carbon and its effects on climate change. Not only does this black carbon arise from a wide range of sources, but it also has numerous effects on climate change, some good and some bad. From this arises questions about which sources of black carbon are easiest to curb emissions from and also which sources of black carbon are having negative effects on climate change and which sources of black carbon are actually helping cool the atmosphere. Discovering just how important a role black carbon has in climate change is critical, but I think that further studies must be done in order to determine how to slow these emissions, especially those emissions that contribute to climate change.

Nick Cianciolo

This article is fairly interesting. Although I have to say I agree with Emily that these statistics simply cant be taken very seriously. If an economist tried to draw causality for something with those weak numbers they wouldn’t be able to get published unless it was a new, enlightening theory. The distinction between different types of black carbon emitters is something I had never considered before. I didn’t realize some forms of carbon have cooling effects. This article has one major flaw in logic that made absolutely no sense. “Developing countries, in particular, could put in place regulations about burning diesel to upgrade their rapidly growing auto fleets.” That costs a significant amount of money… who would bear these costs? Developing countries are the least able to bear costs of upgrading things like the automotive fleet. Yet they state it in the article as if it is a casual small thing to do.

Emily Zankman

As others have stated above, I was surprised about the lack of publicity about the harmfulness of black carbon emissions. However, one of the points in the article that I found most promising is the fact that black carbon emissions wash out of the atmosphere fairly quickly. In my Coastal Policy class, I am currently researching about which flood protection measures in New York City would be most effective given the increasing rising sea level rates and the coast’s susceptibility to damage in extreme weather events (such as Hurricane Sandy). In this research, one of the points that was commonly made is that although it is important to reduce carbon emissions, because CO2 stays in the atmosphere for extended periods of time, the benefits of reducing carbon emissions would not be felt for another 100 years. In light of this article, I wonder if perhaps it would be a more effective, at least in the short term, to focus efforts on reducing black carbon emissions such fuel emissions and coal burning.

Ellison Johnstone

Like others who have commented, I was surprised to learn of both the magnitude of the damage produced by black carbon as well as the lack of knowledge about the pollutant by the general public. Despite being a little skeptical of some of the statistics found by Doherty and her colleagues, I still believe that black carbon presents a serious issue in combatting climate change. It is certainly hopeful that black carbon does not stay in the atmosphere for nearly as long as carbon dioxide does. I think that this presents an opportunity to us to really stem climate change if we can somehow act to reduce the right sources of black carbon very quickly. However, I have some serious doubts about the process of creating effective policy out of the existing knowledge of black carbon. It has been difficult to create policy to reduce carbon dioxide despite very strong and reliable evidence that it is causing massive climate changes. Black carbon is a much less well known issue, which will make it more difficult to rouse the public into supporting policy regarding it. Furthermore, if there is not hard and fast statistical data about its effects, this problem will be compounded. Finally, I also have concerns about the plausibility of black carbon policy in developing countries. Such nations are where major problems result from soot coming from small cooking stoves. Although the technology may exist to easily replace such stoves, I would guess that the costs of doing so would be extremely high. Creating and implementing policy on black carbon, then, will be a major hurdle in future years. However, if it can be done, there is the potential for major progress on climate change.

Dylan Florig

One consideration that came to mind while reading this article was that the black carbon-spewing energy sources have to be replaced by something. This could cost huge sums of money in those developing countries where black carbon is particularly prevalent. The decision for the environment's sake is easy, but when it comes to actually implementing these changes, there are costs that could turn out to be particularly tough for many countries and firms to pay. At the same time, we could create jobs and help the climate in the long term if we invested in better infrastructure and incentivized "going green" for companies that have old equipment, particularly in developed countries like the United States.

I also thought this article was interesting because it made the logic behind black carbon's heating effects seem so simple. It's strange to think that its dark color that absorbs heat is all it takes to create warming in our atmosphere. I was surprised that I hadn't heard of black carbon before, since it seems like it would be fairly easy for scientists to find that it is coming down on snowy areas of the globe. I'd also like to know just how much effect this has on global temperatures. It's not as if the polar ice caps are half covered with black soot, so it's interesting that a relatively small amount of black particles on the snow can have such a big impact on temperatures.

Scott Diamond

This article explores the environmental damage caused by the emission of black carbon, commonly referred to as atmospheric soot. Recent findings indicate that black carbon has the ability to trap a great deal of heat, the power of which is approximately twice as much as was previously estimated by officials. Black carbon has the capacity to increase global temperatures by absorbing heat from the sun, but it can also foster cloud growth that has the ability to cool the atmosphere. As a result, scientists have had difficulty determining the net effect of soot. Current estimates of the effect of soot vary wildly as the confidence interval ranges from .17 and 2.1 watts per square meter of energy. This lack of precision in measurement notwithstanding, I think that targeting reductions in black carbon is a desirable goal especially in light of its negative health effects and how quickly existing black carbon can be washed from the atmosphere. Once again, technological innovations are cited as being the key to reducing the consumption of diesel fuel and coal.

Austin Pierce

It seems as if black carbon is a very viable target for reduced emissions, as it not only has health implications but also has a much quicker rate of removal from the atmosphere. Furthermore, the author presents two sources of production that could easily be reduced. On the coal, this would also provide some form of spillover in the CO2 levels, as even other fossil fuels generally have lower levels of CO2. On the diesel front, I believe that people are overestimating the cost to developing countries based on our USA-centric view. Professor Casey mentioned how the technology for many of these things is already being implemented in countries such as Europe, and if I remember correctly, it is around the same price for such an efficient/clean car as for a gaz-guzzler in the USA. With the pairing of the health and environmental consequences, I believe this is a good place to start to look for lowering levels of warming-emissions.

Brett Murray

It is clear that precautionary action needs to be taken in order to reduce black carbon emissions due to its adverse effects on both health and climate change. Although black carbon is an emerging topic of research that is just becoming explored, there are multiple sources of evidence that already link black carbon (soot) and particulate matter to adverse health effects caused by the combustion of coal and diesel fuels, which I only expect further studies to validate even further. In addition, the new estimate of black carbon's heat-trapping power is more than double than the previous estimates. As this topic is researched in greater depth, the potential consequences of these new estimates from this study could prove to be substantially better or worse than the effects discussed in this article. Thus, it seems like we should be taking precautionary measures until we better understand the effects of black carbon rather than continuing with business as usual (which is of course what we are and will continue doing).

Ultimately, significant action to reduce soot and particulate matter emissions will hinge on the development of new policies. For example, despite many of the adverse consequences associated with the combustion of coal, many power companies continue to rely heavily on coal as one of their primary fuel sources for electricity generation. This is a cheap fuel sources that is linked to significant capital investments in facilities and equipment. Thus, these companies will not start using alternative fuel sources, such natural gas and renewable energies, until government policy offers some sort of incentive or reason to be more concerned with their black carbon emissions. These alternative fuel sources are substantially "cleaner" (& cheaper with natural gas) in comparison to coal combustion, yet companies will maintain their dependence on coal due to the lack of effective policy that aimed at mitigating the effects climate change.

Julia Murray

Like many others, I was surprised to read that black carbon (soot) has such a large effect on global climate change. Others also pointed out that this effect is very imprecise, because the confidence interval ranges from .17 watts to 2.1 watts. While it is true that this is a very wide range and that further research will need to be conducted to determine a more precise estimate, it is also important to realize that we do not have enough for scientists to conduct more and more studies to get extremely precise estimates. Even with preliminary research, it is important for scientists to educate the public about issues related to climate change. As we read in some of our articles for class last week, the public has a very different perception on how scientists view the problem of climate change. Part of this problem comes from the public not being aware of research because it is not as precise as it should be. If we wait around too long to find the exact effects, then it may be too late to take action. Since it is clear from the research that black carbon has some negative effect on the Earth's climate, it is important that we take action now to help alleviate the problem.

Callie Deddens

This article reminded me once again of how much we don’t know when it comes to human behavior and environmental effects. It seems that every aspect of human life comes with a large environmental price tag and the story is never simple. In this case, reduction of black coal comes with the reduction of helpful byproducts as well. In that scenario, the marginal damages do not significantly outweigh the marginal abatement costs. However, the unexpectedly positive message is that in some cases black coal emissions can be reduced relatively inexpensively. Nonetheless, it is clear that a great deal more must be learned in order for the whole story to be understood. As others have commented, the wide confidence interval for energy storage is a little staggering. It reminded me of why the public can be quick to scoff at new research that suggests that their behavior should be altered. Like we talked about in class, people are more likely to believe statistics that confirm their beliefs. I wouldn’t be surprised if some people who read this article would prefer to believe that the reality falls on the low end of the spectrum.

Kate LeMasters

Black carbon emissions are linked closely to carbon dioxide emissions in this article, as both are concentrated sources of global warming, but that does not mean that the solutions to both pollutants are equivalent. They present different effects and call for different solutions. Unlike some comments, I do not think that cutting black carbon is equal to cutting carbon dioxide. For one, black carbon has mixed effects, which makes it a more difficult situation to analyze. Black carbon also has instantaneous effects, so the discount rate that we discussed in class today would not have an effect. The costs today are not less than the costs in the future, so that could change perceptions on actions to take. However, that may create an incentive to pay now instead of later because it is constant.
More striking to me is how localized black carbon emissions are. While carbon dioxide emissions are undoubtedly a global issue, black carbon has more of a local argument. This has significant implications for developing areas that are experiencing an auto boom, as Nick described. Not only does localization have a practical application, it has a moral and ethical one as well. Because developing nations typically have less “green” standards and are in an industrial and automotive boom, they will emit more black carbon (at least on market level) and will have to pay the economic, environmental, and humanitarian costs. Nick rightly questions who should pay for these costs, as placing them all on developing nations is not justifiable. In order for developing countries to truly develop, they must achieve industrial success before they can implement a lower energy-intensity strategy. This problem indeed makes black carbon a global issue, as the cost borne by developing nations must be partially absorbed by developed nations in order for developing nations to reach a threshold at which energy intensity declines. At this point, black carbon emissions, specifically those related to carbon dioxide emissions, will decrease, as many high-energy intensity emissions include both. This result will then place less of a burden on developing nations and help to lower global warming effects through both black carbon and carbon dioxide emissions.

Nathan Plein

I thought that this was a very interesting article and informative in explaining what black carbon actually is. The thing that struck me the most was the complexity of this particle and the amount of research still needed to be done to understand its effects. The cooling and warming effects of these particles is something that I had never heard of and is something that could play a big role in terms of the action we do or don't take against black carbon in the future. I do agree too with some of my classmates above in that this is a different issue than CO2 and should be approached differently.

Another important aspect that this article highlighted was that black carbon not only has an effect on warming the planet, but also has more direct impact on modern life, such as air quality, rainfall in India, and soot in the Himalayas. These more "localized" cost could play a big role in us being able to pass some sort of regulation against black carbon.

Daniel Molon

This article looks into the environmental damage cause by black carbon. Black carbon, or atmospheric soot, is often overlooked in the pollution debate by carbon dioxide; however, black carbon is the second biggest heat-trapper in the atmosphere at 1.1 watts per square meter. So, black carbon is a significant pollutant that should be addressed, but, as the article points out, some black carbon goes into the atmosphere and is used as a shield to prevent heat from entering, and when black carbon is released so is organic carbon molecules, which blocks sunlight and cools the atmosphere. The conclusion scientists have come up with is that by cutting all black carbon production, there would be zero net change in terms of global warming. Black carbon also produces harmful health effects, as it makes people sick and reduces water supply, by making ice melt faster when it falls on glaciers. So, even though reducing black carbon may not be the most efficient way to improve the global climate change dilemma, it is still worth addressing in order to improve overall human health.

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