Science – Page 58 – a sibilant intake of breath

Mistaken assumption about the politics of scientists

An interesting study reveals a disjoint in the United States between how scientists rate their political views and what the general public expects them to be. Whereas 56% of scientists describe themselves as liberal, along with just 2% as conservative and 42% as ‘neither,’ members of the general public surveyed expected 64% of scientists to answer ‘neither,’ 20% to be liberal, and 9% to be conservative. The study also found that scientists are less skeptical of government and more critical of business than members of the population at large.

The blogger commenting on the study predicts that two things would happen if people learned the truth:

“The public would consider scientists to be less authoritative as a neutral source on policy questions, and
Since scientists are respected, the public would become less conservative and more liberal.”

This raises some interesting questions about the relationship between expertise and legitimacy, in relation to the roles of scientists in decision making – the central topic of my M.Phil thesis.

HFCs and climate change

A study published in Proceedings of the National Academy of Sciences updates estimates of the amount of warming that will be caused by hydrofluorocarbons (HFCs) between now and 2050, in a scenario where specific policies to address them are not implemented. These gasses were created as replacements for chlorofluorocarbons (CFCs), which were used as refrigerants and propellants before they were found to destroy stratospheric ozone. The study estimates that without preventative action, HFCs will cause 9-19% as much warming as carbon dioxide (CO2), by 2050. In a scenario where the concentration of CO2 is kept below 450 parts per million (ppm), unmitigated HFC emissions would be the cause of between 28% and 45% of warming.

While CO2 is the most important gas that needs to be managed to produce a stable climate, other powerful gasses like HFCs need to be dealt with, as well. This is being brought about to some extent through the operation of carbon markets, but care must be taken to avoid designing markets that can be exploited, as well as design systems where both CO2 emissions and emissions of powerful trace gasses are effectively discouraged.

One other element illustrated by all of this is how virtually any new technology that gets widely adopted has some sort of negative environmental consequences. This should be borne in mind when hoping that technological progress alone can produce a sustainable world. The technologies of the past always created problems along with new capabilities and benefits. Those of the future will inevitably do likewise.

Sci-fi as a prescriptive genre

Science fiction may be the most prescriptive fictional genre. Firstly, it forces people to consider the consequences of actions and choices across a long timespan. Secondly, it helps to reveal the core ethical values people have: it presents both our aspirations and things that inspire fear, disgust, and outrage. Finally, it makes statements about contemporary ideologies by presenting them with false hindsight.

As such, though sci-fi has a sometimes deserved reputation as an escapist genre, it can also be among the most directly ethically and politically engaged. It also serves a historically valuable purpose, by revealing how those in the past imagined the future. For instance, look at Asimov’s projection that everything would be nuclear-powered in the distant future, even small toys for children. It is no surprise that today’s sci-fi has ecology as a key focus. It would be fascinating to know how it will be read in a century.

Carbon-neutral aviation

The climatic impact of aviation

At present, virtually all freight and passenger-carrying aircraft operate in one of two ways: burning kerosene to turn a propeller, generating thrust that the wings partially convert to lift, or generating thrust by burning kerosene in a jet engine. Virtually all of that kerosene is produced by refining petroleum. As such, burning it adds to the stock of greenhouse gasses in the atmosphere. These include carbon dioxide (CO2) (a basic product of the combustion) and other greenhouse gasses (GHGs), like nitrous oxide (NO2). It is also possible that aircraft have an effect on cloud formation (both by producing vapour trails and inducing cirrus cloud formation), but my understanding of the science is that scientists aren’t sure whether that has a net warming or a net cooling effect. The latest IPCC report says:

Moreover, the uncertainties on some aviation forcings (notably contrail and cirrus) are still high, such that the overall radiative forcing consequences of changing cruise altitudes need to be considered as a time-integrated scenario, which has not yet been done. (p. 355)

Helpfully, the report does identify that, if contrails prove to be a significant problem, they “can be easily avoided – in principle – by relatively small changes in flight level, due to the shallowness of ice supersaturation layers.” There is also some uncertainty about the relative emissions of short-lived but potent GHGs like nitrous oxide, compared with long-lived but less potent ones like carbon dioxide. All told, the report does conclude that aviation has a “larger impact on radiative forcing than that from its CO2 forcing alone.”

Carbon neutral possibilities

A couple of logical possibilities exist for making air travel carbon-neutral, though they differ in practicality. Electric planes are conceptually possible, and small versions exist. As I understand it, the big problem is storing enough energy in light enough batteries. My sense is that we are nowhere near being able to do this for large commercial aircraft. Similar issues exist for hydrogen aircraft, in term of storage, and there is the added question of where we get the hydrogen. To me, biofuels seem like the most plausible near-term option. That being said, there are technical issues to be overcome within aircraft themselves, such as the gelling of biofuels at the low temperatures found at high altitudes. While some airlines have tested multi-engine planes with a single engine running on a biofuel/kerosene mix, as far as I know nobody has flown such a plane exclusively using biofuels.

Additionally, not all biofuels are carbon neutral. Ethanol derived from corn might actually represent more greenhouse gasses than an equivalent amount of gasoline, once you factor in fertilizer production, emissions from farming and farm equipment, ethanol fermentation, etc. The same might be true of palm oil derived biofuels, given how their production can lead to the destruction of rainforests that are major carbon sinks.

My sense is that the air travel industry has yet to demonstrate that it will be able to exist in a carbon neutral world, regardless of how expensive tickets become. That being said, it does make sense to displace emitting activities in order from lowest cost to highest cost. If we can replace fossil fuelled ground vehicles with electric vehicles running on renewable power, we should do so first before pouring enormous effort into trying to produce a carbon neutral aircraft. That being said, there does seem to be a strong moral imperative to reduce emissions generally, including by limiting the amount of long-distance travel we undertake.

As usual, I expect any mention of aviation to produce a lively discussion.

Cell phones while driving

Over at Slate, William Saletan argues that cell phone use while driving is dangerous enough to warrant a ban. This is because the magnitude of distraction is comparable to an illegal level of intoxication, and because it arises from the mental effort involved in conversation, not the physical handling of a phone. As such, hands-free handsets do not address the problem.

As a cyclist who frequently rides in proximity to cars, it makes sense to me that driving and using a phone should be illegal. Drivers of cars are voluntarily undertaking an activity that poses a serious risk to the lives of others. As such, it is entirely proper to require them to conform to rules that reduce the probabilities of causing injuries and deaths. I am less sure about how the law could be effectively enforced. Technical measures are conceivable, but will always carry the risk of false positives and false negatives. Simply relying on police officers who spot offenders to issue tickets would not be very comprehensive. Can anyone think of a good way by which such a restriction could be enforced?

Climate change and the Colorado River

A study conducted by the University of Colorado at Boulder has concluded that there is a 50% chance of the Colorado River system “fully depleting all of its reservoir storage by mid-century assuming current management practices continue on course.” The authors of the study have determined that could reduce average stream flow by 20%, which translates into a 50% chance of fully depleting reservoir storage. That storage capacity amounts to more than 60 million acre feet, nearly four times the ordinary annual flow of the river.

To appreciate the potential significance of such a development, one need only consider that the river powers more than a dozen dams, and serves the water needs of 30 million people. Replacing the electrical output provided by the dams would be a very difficult matter, and the water restrictions that would accompany declined availability would challenge agriculture, industry, and residential development. The study illustrates some key points about climate change:

People in rich developed states are also vulnerable
Serious impacts could arise in the medium term
Significant aspects of our current economic system could be disrupted in the coming decades, if we fail to reduce our emissions

Hopefully, these messages will get through to voters and policy-makers, and the kind of mobilization required to cut emissions will begin.

Carbon-neutral Tuvalu

Tuvalu, one of the small island states that faces a literal threat of obliteration due to climate change, has vowed to generate all of its energy from renewable sources by 2020. The estimated cost of doing so for the nation of 12,000 people is US$20 million.

The approach is a sensible one, given that the only hope for such states is swaying the world’s major emitters into being more aggressive about emissions reductions than they would otherwise be. Nevertheless, the prognosis for states like Tuvalu and the Maldives is pretty bleak. When rich states talk about ‘dangerous’ climate change, they seem to be defining it largely in terms of their own national interest. Furthermore, most states still haven’t adopted targets consistent with stabilizing greenhouse gasses at a level likely to avoid more than 2°C of temperature increase, and none have taken serious steps towards implementing a plan capable of reaching those targets.

The Desertec solar plan

As reported in The Economist, Munich Re has invited 20 large companies to form a consortium, intended to build concentrating solar power stations in Africa and the Middle East, as well as the high voltage direct current (HVDC) lines required to bring that power to Europe. The stations will use molten salt heat storage, so as to be able to generate power day and night. Munich Re, the world’s largest reinsurer, is motivated by concern about its exposure to climate change. Fully implemented, the scheme would cost $560 billion and provide 15% of Europe’s projected energy demand in 2050. The complete system would cover 17,000 square kilometres of territory.

Desert solar as a renewable energy option has come up here before.

All told, the plan is very promising. It is refreshing to see companies thinking strategically about the long-term harm climate change could do to them, as well as the long-term opportunities associated with renewable energy. A report produced by the Wuppertal Institute for Climate, Environment and Energy and the Club of Rome determined that the project could produce 240,000 jobs in Germany, as well as €2 trillion worth of electricity by 2050.

Even more importantly, it could demonstrate the feasibility of the desert concentrating solar / HVDC option, which could be extended to the Southern US and elsewhere. As David MacKay explains, this is one of the renewable options where the figures add up, and it could be possible to generate the kind of energy societies demand. Here’s hoping the Desertec plan helps lead the way.

Projecting sea ice minimums

Over at RealClimate, there is a discussion about projecting the summer sea ice minimum in the Arctic. As readers may recall, the 2007 minimum was unexpectedly low. 2008 was still worse than projected by the IPCC, but not as bad as 2007. All indications are that this year’s minimum will still be below even the most pessimistic IPCC projections.

In addition to being less extensive than before, the Arctic sea ice is also thinner and newer – less and less consists of multi-year ice, and an increasing share consists of ice that forms in the winter and vanishes during the summer months. All this is bad news for species that depend on the sea ice, such as polar bears.

Palin’s content-free opposition to carbon pricing

Sarah Palin, former governor of Alaska, has produced an op-ed for The Washington Post attacking the Waxman-Markey bill, and the idea of using cap and trade to reduce greenhouse gas emissions. She argues:

It will prevent economic recovery.
It will make energy too expensive.
Job losses will result.
Costs of agriculture, transport, and manufacturing will rise.
Drilling in Alaska and building pipelines is a better option.
The US has lots of coal, and could build a lot more nukes.

Notably, she doesn’t even pretend to offer a solution to climate change, the primary problem the Waxman-Markey bill aims to address. This is remarkably myopic. Even if we accept that all of her assertions are true, this op-ed brings us no closer to making an intelligent decision on climate change and energy policies, since it doesn’t really contemplate alternative mechanisms through which climate can be stabilized and dependence on non-renewable fuels can be overcome. To imply that the US can get by with a bit more drilling is deeply fallacious. Similarly, it is misleading and dangerous to suggest that the American economy would keep ticking happily along indefinitely, even if climate change was totally unrestrained and allowed to follow its most destructive course.

We can only hope that the US Senate will be a bit more far-seeing in its analysis and deliberations, more willing to consider the key motivations for energy policy, and ultimately seized of the importance of sending a strong and growing price signal, so as to progressively and deeply curb the release of harmful and threatening greenhouse gasses.