Guest blog #25: Ashwin Salvi on greenhouse gases and reforestation

Here are some thoughts from Ashwin, a previous guest blogger, on reforestation. I appreciate the post, particularly because its nature is different than what is typically written about on the blog.

Over the past few years, there has been a lot of talk about carbon dioxide (CO2) sequestration to combat climate change. Sequestration is, in a nutshell, the capturing of airborne CO2, which has a warming effect on the climate, and storing it in liquid or solid form, either underground or on the surface. Darshan has written about such geo-engineering approaches and the ethical and procedural justice issues surrounding them previously. Today, I want to focus a bit more on the technical aspects of sequestration.

A recent Michigan Energy Club lecture got me thinking about CO2 sequestration via reforestation to reduce the presence of CO2 in the atmosphere. While replanting trees is a good idea, the issues are a bit more complicated once they are unpacked a bit.

Firstly, it is important to note that growing trees does absorb a considerable amount of CO2 from the atmosphere. It is estimated that that global forests absorb ~20% of CO2 emitted from fossil fuel combustion. However, all living things respire; trees also emit CO2 via respiration! While the amount of CO2 released through respiration is less than the CO2 absorbed for their growth, the point is that we cannot forget that the CO2 and trees is not a one-way operation. In addition and possibly more significant, trees also emit a variety of hydrocarbons (HC) that can lead to increased tropospheric ozone levels. Of course, these biogenic emissions are completely natural. (Click here to read about an interesting study comparing HC emissions from different trees.) It is what is anthropogenic that is of deeper concern.

Furthermore, it also matters where reforestation takes place. Trees growing in tropical climates are more effective at absorbing CO2 than those growing in higher latitude forests. Higher latitude forests have actually been seen to produce a net warming effect on the climate. The darker leaves of these trees absorb more heat and outweigh the cooling effect CO2 absorption and evapotranspiration. This is because the albedo, or reflectivity, of the earth’s surface changes from a higher value (with snow), to a lower value (darker leaves), making less of the incident solar radiation reflect back into space. In addition, higher latitude forests experience seasonal effects, reducing their ability to absorb CO2 due to tree hibernation.

Tropical forests are seen to be more effective at CO2 absorption due to faster growth rates stemming from year round growth, abundant sunlight and rain. In addition, evapotranspiration from the leaves of trees also contribute to a net cooling effect.

Let’s think further down the line, though, toward the end of the tree’s life. The tree spent its entire life absorbing carbon from the atmosphere and now that the tree is dead, where does the carbon go? Well, as the tree decomposes, the carbon goes back into the atmosphere as CO2 and methane, with methane being one hundred times more potent a greenhouse gas than CO2. So while, the tree does a great job taking carbon out of the atmosphere while it is alive, the problem of greenhouse gases in the atmosphere really isn't solved, but just kicked down the road; the tree is just an ephemeral holding box. Therefore, trees as a means of CO2 sequestration will help in the shorter term, but a longer term solution (like reduction of emitted CO2) must be what is tackled.

Adequate answers?

My contention is that the scale of the largest problems a social structure or culture can create is larger than the culture is able to deal with. Let's take the example of climate change. For years now, countries have done very little substantively to address the issue. Sure, there may be some countries that have adopted renewable energy standards, while some have signed and ratified the Kyoto Protocol and have made progress towards reducing their climate-changing emissions. But unfortunately, we can still wave many Small Island States like the Maldives bye bye--the levels of greenhouse gas emissions has steadily increased over time, and we are probably not going to keep surface temperatures below semi-acceptable levels:

“I am very worried. This is the worst news on emissions,” [IEA chief economist] Birol told the Guardian. “It is becoming extremely challenging to remain below two degrees. The prospect is getting bleaker. That is what the numbers say.”

The IEA says that for a two degree increase to be averted, global energy-related emissions in 2020 must not be greater than 32 Gt. This means that over the whole of the next decade, emissions must rise by less than they did between 2009 and 2010. (emphasis added)

The agency also estimates than 80 percent of projected emissions from the power sector in 2020 are “locked in” – that is, they will come from existing power plants or those currently under construction. This will make it even harder to meet the two degree target, Birol says.

For me, climate change has been caused because of a continued reliance of society on technology. Sure technologies have become more efficient, afforded people longer lives, increased mobility, the ability to talk to people from across the world, and so on; I cannot deny this. But it would be foolish to not think that many of those technologies have resulted in ecological degradation and climate change, be it electricity generation, mining, and transportation. Technology and society have a dynamic role--one shapes the other in an endless interplay. At the same time, however, our answers to the problems of technology have created more technologies...and more of them...and more of them, rather than ask deeper, more powerful questions.

What this represents is a mindset that is ingrained in the social structure. This ingraining takes away our ability to think about what is causing the problems we face. Instead, we try to forcibly bin or address the problems we've created using the structures in place. Add on top of this political processes and inequality of power, and we are mired in gridlocked decision-making, in which traditional forces of society are called upon to address problems it could not foresee. I can see how "internalising the externalities" (say by having a carbon tax) can alleviate problems of greenhouse gas emissions, how "efficiency" can lead to decreased extraction of materials from this Earth. But are the mindsets [a reliance on technology, "It really doesn't matter if I do anything to reduce my environmental impact, what we need is a large movement," etc.] and social structures [like large government, like "industry," like "free (ish, kinda, maybe sorta) markets," etc.] we have really adequate enough to deal with the problems we've created? I am not so sure.

What does this mean we do in our daily lives? It means that we continue to question what is thrown at us, that we continue to question the motives of large entities (for many governments and corporations advocate for "solutions" that do not hurt the bottom line), that we make choices here and now that would be obvious in a more sustainable world.

Specific concerns about the bridge in Detroit

This post is a continuation of yesterday's post, which was inspired by comments from Matthew. I will address some specific concerns he had about another post from a few days ago. But before that, I want to mention the specific reasons why the bridge is being built.

Many of you probably know that the Ambassador Bridge, owned by Matty Maroun, is the largest trade crossing in the US. This bridge is privately owned, and the monies from the crossings go directly to Maroun's Detroit International Bridge Company. The State has basically been missing out on money for the longest time; the Ambassador Bridge is basically a monopoly. Therefore, they've decided to have their own bridge. On looking at the environmental impact statement (EIS) made by the Michigan Department of Transportation (MDOT), the reasons for the new bridge are to:

• provide safe, efficient, and secure movement of people and goods across the U.S.-Canadian border in the Detroit River area to support the economies of Michigan, Ontario, Canada and the United States
• support the mobility needs of national and civil defense to protect the homeland
• provide new border-crossing capacity to meet increased long-term demand
• improve system connectivity to enhance the seamless flow of people and goods
• improve operations and processing capability in accommodating the flow of people and goods 
• provide reasonable and secure crossing options in the event of incidents, maintenance, congestion, or other disruptions

Given these reasons, I will address Matthew's specific concerns...

Yes, the bridge will undoubtedly cause more local air pollution, this is true of all development not just the bridge. 
This is an interesting point of contention. There are various perspectives. One is that Delray has been a heavily industrial area - cement, paper, steel, coal, waste water, oil refining, etc. - for many decades, and zoning laws have allowed industry to move in right next to residences. Now, the bridge can do one of two things for industry - by taking up a one hundred and sixty acre footprint, there are that many fewer acres left to fill industry in. This is the position taken by MDOT. So maybe some air pollution is being mitigated? Whoe knows. On the other hand, industry may want to be closer to the bridge, given that there will be easier access to Canada. This is the position of Southwest Detroit Business Association. This may increase air pollution in the area. My position is that people should not be living in Delray at all, and while localised air pollution many be diffused because of the bridge, the cumulative and global impacts of the pollution cannot be neglected.


You suggest, but have not shown, that not building the bridge will be better for the environment overall. Not building the bridge may mean that the net number of miles that goods are transported is increased, which would mean each of your concerns would be amplified not reduced (i.e. it seems unlikely that the alternative is mostly local production of goods). 
I looked into this, and MDOT does a wonderful job at skirting these issues. In the detailed EIS statement, MDOT says, 


"...With respect to global warming, to date no national standards have been established regarding greenhouse gases, nor has EPA established criteria or thresholds for greenhouse gas emissions. But, on April 2, 2007, the Supreme Court issued a decision in Massachusetts et al. v. Environmental Protection Agency et al. that the USEPA does have authority under the Clean Air Act to establish motor vehicle emissions standards for carbon dioxide CO2 emissions. However, the Court’s decision did not have any direct implications on requirements for evaluating transportation projects. Further, because of the interactions among elements of the transportation system as a whole, project-level emissions analyses for greenhouse gases are less informative than those conducted at the regional, state, or national level. Because of these concerns, FHWA concludes that CO2 emissions cannot be usefully evaluated in this EIS in the same way as other vehicle emissions. With With respect to health impacts, the “Interim Guidance on Air Toxics in NEPA Documents” indicates that presently there is not adequate science to reliably include exposure modeling or risk assessment in the air quality analysis. The Interim Guidance explains that modeling tools to generate air pollution emissions cannot be properly used at the project level because they are based on certain assumptions with regard to trip length and amounts of congestion and were based on a limited number of tests of mostly older vehicles. Dispersion models that would indicate how much particulate matter and air toxics are in the air were developed to deal with carbon monoxide, which is relatively non-reactive, and their intent was to determine maximum, not more typical levels. Further, little is known about background pollution levels in many areas. Even if emission levels and concentrations could be estimated, exposure assessment and risk analysis have their own shortcomings, due to extrapolation to annual levels, for example, let alone multiple years."

There are a few things I'd like to mention regarding this. First, and the most obvious, is that the environmental impacts have not been addressed at all with this study - I will save you the pain of having to go through this terrible assessment. I don't understand why it is called an environmental impact statement at all. Second, even if the assessment was conducted, the reasons why the bridge is being built would still completely supersede the environmental impacts. MDOT would say, "Deal with the impacts." Third, such life-cycle assessments can be tailored to give you the answer you want, based on the variables you choose to include in the assessment. My stance is this, the impacts are debatable, what is not debatable is that these impacts are negative.


Having more local revenue could increase peoples salaries which may be more positive than the air pollution is negative. It is not reasonable to assume that people’s lives won’t be dramatically improved by having additional money (e.g. better healthcare, education, healthier food, more money for environmental remediation, etc.). 
I don't think that there should be a tradeoff between salaries and pollution. As I have written about before the choices we've made so far have always pit one important thing against another. What such behaviour connotes is that a degraded environment is necessary for people's lives to be "better." What this also means is that we convert the most important thing, our environment, into something expendable and movable (money), through degradation, and then use that expendable thing we've created to buy back the most important thing. Speaking of entropy, I think there are losses here...

What if scientists quit?

As any person that does research would tell you, any probing into nature and complex systems always raises more questions than answers. As a chemical kineticist, I can assure you that people haven't even agreed on the kinetics of hydrogen+oxygen, the simplest group of reactions physically possible in combustion. (I am at times worried that fist fights will break out at conferences over peoples' differences in the understanding of these simple kinetics.) As humans, we are curious, and it is nice to "know" more about how things and the world work. But inevitably, the rise of more questions makes us think that we should find the answers to those questions, which inevitably leads to more research. In no way am I saying that all research is bad, but I believe that there comes a time when more research is not the best use of our time, of our energy, of our emotions.

Climate change is a fitting example of this. We have known for decades now that greenhouse gases are responsible for climate change, and that it is humans that are responsible for the emissions of these greenhouse gases. Yet, there is more and more research being done into climate change, and more and more articles and assessments being published, and more and more grants being written, and more and more time and effort and money being expended. We are never going to know how the climate works totally, but we do have a good enough understanding of how it does. And more fundamentally, we know (we know, we know, we know, we know!) that our behaviour, our ethics, are driving us to release more and more greenhouse gases. What should we do about this knowledge? (Of course the techno-optimists will say, 'We need better technology.' Well, we know how well that has worked out...) More research is probably leading to more lost time.

What if scientists said, 'Enough is enough! The best use of our time is to actually mobilise and act on our findings, not to beat a dead horse and learn more about the nuances of climate.' What if scientists quit? What if they boycotted "research" and became activists? Many of you might say, 'Well, scientists are socially awkward, and they'd be terrible organisers.' Okay. But think about the power that they have. They are the ones bringing in money to institutions of "learning." They are the ones that are teaching the youth about the issues. And they are the ones that know full well how our behaviours are leading to ecological degradation. We know all that we need to know to make huge strides towards treading lightly on this planet. We just need to take those steps.

Many people have talked about the role of scientists and engineers in public policy. Robert Pielke Jr. does a good job at delineating those roles in his book The Honest Broker. But the roles that he talks about assumes that scientists rest within the current structures of society that lead to much inertia - the government-university-industry complex. Only a handful are out there, writing more publicly, trying to organise and mobilise.

What we lose through "efficiency" - Jevon's Paradox and complexity

My previous posts (here and here) focused more on the less quantifiable aspects of "efficiency," such as taste and flavour, as well as balance in nature. Today's post is a more technical post, primarily focusing on energy and economics, following up on my last two posts. Humans have always had a tendency and will to make things more "efficient" - we would rather our shopping be done at one place, we would rather a computer simulation take half as long as it currently does, we would rather pay half of what we do for our heating bill. What we believe is that making things and activities more efficient will allow us time to do other things, or allow us to do more for less. In practice however, this has a perverse feedback associated with it - we may end up using more by making things more "efficient."

A recent article in The New Yorker by David Owen was titled, "The Efficiency Dilemma: If our machines use less energy, will we just use them more?" Owen writes about Jevon's Paradox, which was first written about by a young English economist, William Stanley Jevons, in 1865. The paradox states that instead of using less by making things more efficient, we end up using more. This phenomenon is called "rebound." When the savings through efficiency are canceled out and overwhelmed by increased consumption, the phenomenon is called "backfire." When something becomes more efficient, the implicit price of it drops from a neo-classical standpoint (and we all know that the world runs, unfortunately, on neo-classical economics), thus spurring increased demand.

Owens gives a most wonderful example about refrigeration and air-conditioning, both energy-hungry processes. As refrigerators have become more efficient, refrigeration capacity in the world has increased multi-fold. Furthermore, the effects of better refrigeration are not limited to refrigeration only. We are tempted to buy more food to store in refrigerated conditions, and by the time we get to eating them, much of the food is spoiled anyway. Here, not only do we waste the energy going into refrigeration, we waste and throw away all of the energy, chemicals and resources that went into food production, through transportation, storage and agriculture. In fact, (and this was incredibly shocking to me), one quarter of US freshwater use goes into food that is eventually thrown away. As you may be able to tell, after a certain point, it becomes difficult to know what the true effects of efficiency gains are when moving to studying small systems to larger systems; issues only become more complex, becoming much more difficult to address. (I have written about complexity here, here and here.) Owen makes the point that, along with advocating for "efficiency," there must be other measures adopted simultaneously to make sure gains are not canceled out by increased consumption. Indeed, without further measures, you may be left in the boat of the United Kingdom, which has seen marked increases in "efficiency," but only increased greenhouse gas emissions.

There are several questions worth thinking about here: Do we need things to be more efficient? What is so wrong with things being inefficient, especially from a personal time standpoint? What are we going to do with any efficiency gains that will come our way?

Trash, to me, seems like a natural outcome of this "efficiency," "centralisation," and "convenience" mentality.

Why focus on trash and waste?

Katie asked me a pointed question on Thursday, while we were talking about nuclear waste - "Some people say focusing on a problem like trash takes away from devoting energy to more significant environmental problems. What do you think?"

Trash is visceral. We feel trash. We smell it, touch it, and hear it, sometimes every day, several times a day. When we go out to dinner, we use napkins to wipe our hands. When we crack open a bottle of wine, we rip off the wrapping hiding the cork. As soon as we're done with a plastic bottle of orange juice, some of us lift lift the lid of the trash can in our kitchen and throw the bottle out. The yard of a college fraternity house is littered with plastic cups on game day. We hear the early trash collectors with their huge truck at the crack of dawn, lifting and crushing pounds of trash. A trash bin filled to the brim releases a putrid smell that just makes us want to walk away. Indeed, trash, when we are near it, suffers way less from a problem of perception than do our other friends, such as greenhouse gases. Take carbon dioxide for example. When we flip on the light switch, the light appears here, but the odorless, colourless carbon dioxide is emitted elsewhere. How many of us can visualise such an invisible threat? What does 385 parts per million mean? That means that out of a million, there are 999,615 parts of other gases. Greenhouse gases suffer from a perception problem.

But that doesn't mean that trash and greenhouse gases aren't related. The social, economic and philosophical structures in place that cause the formation of trash and greenhouse gases are the same. Trash is just a different manifestation of the same problem - consumption without limits, carelessness about the future and disrespect for the ecosystems of the present.