Category: Science

New discoveries, the scientific method, and all matters relating to the scientific study of the physical world

Greenhouse gases other than CO2

Rusty metal pipes

A recent Newsweek article discussing Al Gore’s new book made reference to recently published work on how different gases are contributing to anthropogenic climate change: Improved Attribution of Climate Forcing to Emissions, written by scientists from NASA’s Goddard Institute including Drew Shindell and Gavin Schmidt.

Two especially notable points are made. Firstly, the researchers estimate that carbon dioxide (CO2) is ‘only’ responsible for 43% of observed warming, once interactions between gases and aerosols were taken into account. At the same time, methane accounts for 27% of warming, halocarbons 8%, black carbon 12%, and carbon monoxide and volatile organics 7%. Secondly, there are the policy implications that flow from this. Preventing CO2 emissions basically requires reducing deforestation and the burning of fossil fuels – with the latter being an especially challenging thing to do in a world as promiscuous with energy as ours. Reducing methane, by contrast, may be as simple as capturing and burning gases from landfills, and adopting other comparatively low-cost and low-sacrifice strategies. The authors conclude that strategies that incorporate all greenhouse gases (GHGs) are “likely to be much more cost-effective than CO2-only strategies.”

There are other complications involving GHGs, including atmospheric lifetime. CO2 is removed by various means, across different timescales. Methane doesn’t last as long, but does cause more warming than CO2 when present and often breaks down into it later. Black carbon is washed out of the atmosphere quite quickly, meaning that eliminating its production could yield reduced radiative forcing relatively quickly.

The greater importance of non-CO2 gases described in this study is potentially good news for climate change mitigation, given how challenging it has been to convince governments to accept even very minor costs in order to reduce the risks associated with climate change. Developing an improved understanding of exactly how much various GHGs alter the climate should also allow for more efficient carbon pricing, where the incentives to reduce the most harmful GHGs are the strongest.

Mapping 4°C of warming

The UK’s Met Office has released an interesting interactive map showing what the world would be like with a 4°C rise in global temperatures. Impacts considered include fires, agricultural impacts, water availability, sea level rise, loss of permafrost, extreme weather, health, and more.

The map also shows how Canada’s high latitude location will mean more than average temperature increases across the country, ranging from around 7°C to more than 10°C.

There is more information about the map over at World Changing Canada.

Can Canada meet the Conservative GHG targets?

Small red apples

The Globe and Mail is full of coverage of a ‘landmark’ new report, considering whether and how Canada could meet the stated greenhouse gas reductions of the current government (20% below 2006 levels by 2020, 60-70% below by 2050). The report was paid for by the Toronto Dominion Bank and compiled by the Pembina Institute and David Suzuki Foundation. Economic modelling was done by M.K. Jaccard and Associates Inc, Canada’s ubiquitous non-governmental providers of projections on climate plans.

The report includes estimates of what the GDP cost of meeting the government’s targets would be, for each province. Overall, the cost is estimated at 1.5% of GDP in 2020. Alberta would be the most affected, with an economy 8.5% smaller than it would be in a scenario with new restrictions on emissions. Saskatchewan is projected at -2.8% and B.C at -2.5%. Ontario would actually be 0.9% richer with regulation, while Quebec would be 0.3% poorer. Given the risks associated with climate change, such an investment seems appropriate. That is especially true when you recognize that we will inevitably have to abandon fossil fuels anyhow.

Of course, much depends on the precise methodology used to compile the report. It isn’t clear how the government’s Regulatory Framework would actually operate in practice – for instance, which compliance options firms would choose to employ, and how much of an effect that would have. The plan also assumes that carbon capture and storage (CCS) will rapidly emerge as an effective and affordable technology, though it isn’t quite as dependent on that outcome as Alberta’s even more worrisome climate plan. In an editorial by Jeffrey Simpson, he claims that:

The government must know its policies will fail. But if the Conservatives expect people can be fooled or will tune out because they don’t care or the issue’s too complicated, why not?

Another editorial argues that the targets were set without a plan for achieving them established. Very disappointingly, it then goes on to argue that since meeting Canada’s targets would involve “unacceptable damage to Canada’s economy and national unity,” the targets should be further loosened. What this ignores is the critical issue of dealing with climate change. If Canada and the world fail to adopt effective mitigation policies, the alternative isn’t going to be unity and prosperity amidst ever-higher greenhouse gas concentrations and temperatures. The future of Canadian and global prosperity depends on maintaining a climate that is compatible with human prosperity. Furthermore, it seems absurd to say that growth of 8.5% below business-as-usual is a terrifically awful thing to inflict on Alberta. That’s the kind of impact that might arise as the result of some modest global economic blip or disruption in fossil fuel markets. Only in this case, the cost would be borne in order to help Canada make a credible start on the critical path to a low-carbon economy.

The ethics of letting Alberta and the oil sands off the hook are also highly dubious. People don’t have the fundamental right to keep doing what they have been, even when it becomes overwhelmingly obvious that their actions are harming others. Aside from those suffering now from the air and water pollution associated with rampant oil sands development, there is the key issue of the defenceless and innocent members of future generations who will suffer as the result of these emissions. Indeed, extracting and burning just 10% of the oil sands resource would release 15 billion tonnes of carbon into the atmosphere, a quantity sufficient to have a significant temperature effect in and of itself. In addition, continued failure to act on the part of Canada makes it less likely that a strong international agreement will emerge. Given the importance of reaching such an agreement soon, and setting the world on the path to decarbonization, more foot-dragging from Canada is shameful and inappropriate.

Among others, I have long argued that the targets lacked a credible plan for implementation. The government seems to be banking on the fact that they won’t be around in 2020 or 2050 to be held to account. As such, nearer term targets – such as those in the 10:10 campaign – could be usefully adopted in Canada. Anything else leaves too much of a gap between promises and mechanisms of accountability.

The full report is available online (PDF).

Climate change and food production

A recent report from the International Food Policy Research Institute highlighted the degree to which climate change threatens global agricultural output:

In parts of the developing world some crop yields in 2050 could be only half of their 2000 levels. Irrigation may not help: climate change will hit irrigated systems harder than rain-fed ones. And the hope that gainers from climate change will outweigh losers looks vain: the damage from higher temperatures and erratic rainfall will be too big.

Couple that with ever-increasing population, and you have a recipe for a lot of suffering and strife.

Flu vaccine ethics

Electrical meters

An article in today’s Globe and Mail argues that it is selfish for people to refuse the H1N1 flu vaccine, given the risks it creates for other people. The argument is a pretty strong one. The chances of suffering serious side effects from the vaccine are very low, the illness is a serious one, and people who could get vaccinated choosing not to do so does very plausibly cause harm to others.

Firstly, people hospitalized with preventable swine flu will occupy beds and the attention of medical staff, to the detriment of other patients. There is also a chance they will make medical personnel sick. Refusing to get vaccinated also threatens those who are immunosuppressed.

Medical ethics is often a challenging field in which to reach conclusions about what behaviours are admirable, which are dubious, and which should be prohibited. There is often a trade-off between individual autonomy, individual risk and reward, and collective risk and reward. In this case, I think those who choose not to get the vaccine as mis-applying their autonomy. That is on account of a faulty perception about the risks and rewards they face. That said, I am wary of saying that people other than primary care providers should be mandated to take the vaccine. If anything, that might produce a more harmful backlash in the long term. That said, I think it is fair to say that people who choose not to get the vaccine probably aren’t acting very intelligently or empathetically.

[Update: 18 November 2009] I got the vaccine tonight – the first evening when it was available for non-priority groups in Ottawa.

The climate impact of pets

A new book estimates that the climate change impact of pets is considerable:

In a study published in New Scientist, they calculated a medium dog eats 164 kilograms of meat and 95kg of cereals every year. It takes 43.3 square metres of land to produce 1kg of chicken a year. This means it takes 0.84 hectares to feed Fido.

They compared this with the footprint of a Toyota Land Cruiser, driven 10,000km a year, which uses 55.1 gigajoules (the energy used to build and fuel it). One hectare of land can produce 135 gigajoules a year, which means the vehicle’s eco-footprint is 0.41ha – less than half of the dog’s.

They found cats have an eco-footprint of 0.15ha – slightly less than a Volkswagen Golf. Hamsters have a footprint of 0.014ha – keeping two of them is equivalent to owning a plasma TV.

Just another thing that needs to be tallied up when considering one’s individual climate impact. It is also another reason to support carbon pricing, such as through an economy-wide carbon tax. Such a tax would make people consider the climatic impact of their pets more appropriately, and possibly consider smaller and/or vegetarian options.

All that being said, having a pet is a lot less carbon intensive than having a child. For those out there who are using dachshunds or tabbies as alternatives to procreation, carry right along.

LED lighting, effectiveness and efficiency

Perhaps the only thing that will ever silence the various overblown objections to compact fluorescent lights is when they are replaced by solid state lighting systems, based on light emitting diodes (LEDs).

Unfortunately, as a post on BoingBoing points out, there is still a way to go before such lighting systems will be viable options for most people. For one thing, they are still expensive. For another, the light they produce may start out not being white, or drift away from being white over time. Worse, it is very difficult for people to distinguish between high and low quality products currently on offer.

Another problem is that LEDs aren’t unambiguously more efficient than fluorescent lighting systems: “The more lumens per watt, the better the energy efficiency. The kind of fluorescent lamps used in offices–the long, narrow ones that are called T-5 or T-8s in Technicalland–regularly get more than 100 lumens per watt. An LED T-8 lamp tested by CALiPER last year got 42.” It seems those of us pushing for more energy efficient lighting may have to continue rebutting claims about mercury and flickering for some time yet.

Growing climate skepticism in the US

Red leaf in a pond

In an awfully pathetic development, a recent poll conducted of 1,500 American adults by the Pew Research Center found that the proportion agreeing that “there is strong scientific evidence that the earth has gotten warmer over the past few decades” has fallen from 71% to 57%. Now, only 36% of people agree that human activities are the drivers of temperature increase.

This is an astonishing result, a year after the IPCC’s Fourth Assessment Report argued that “[w]arming of the climate system is unequivocal” and that “[m]ost of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic (human) greenhouse gas concentrations.” It is especially sad given the fact that the supposed scientific debate about the causes of climate change is largely mythical. Despite that, status quo supporting groups have apparently done an excellent job of misleading the public, perhaps aided by the increased concern that now exists about the state of the global economy.

The basics of the situation are quite simple. No competent chemist would disagree that burning fossil fuels adds carbon dioxide (CO2) to the atmosphere. Similarly, it is simple to observe that air with more CO2 blocks more outgoing infrared radiation, warming the planet. Both of these things are explained by chemical and physical theory, and observed in practice. Admittedly, it takes more work to understand why this warming could be dangerous; still, the scientific backing for that claim is incredibly robust and based on peer-reviewed scientific work done around the world over the course of many decades.

Obviously, a lot more work needs to be done debunking climate change deniers, both by directly responding to misleading arguments and through other means. The terrifying thing here is that our actions now will have irrevocable consequences, largely beginning a few decades out, but continuing at least for thousands of years. The fact that so many people remain confused about climate – and very few support effort on the scale required to deal with it – is really bad news for future generations.

A trillion tonnes of carbon

Previously, I described how Andrew Weaver used different estimates of how sensitive the Earth’s climate is to greenhouse gasses to determine how many total emissions humanity can have without causing more than 2°C of warming. The 2°C figure is commonly cited as the level of warming that is unambiguously ‘dangerous’ – either because of the harm it would do directly or because warming to that point would kick off positive feedbacks that would then make the planet hotter still.

A new site simplifies this analysis, arguing only that: “If we are to limit global warming caused by carbon dioxide emissions to less than 2°C, widely regarded as necessary to avoid dangerous climate change, we need to limit total cumulative emissions to less (possibly much less) than” one trillion tonnes of carbon (equivalent to 3.67 trillion tonnes of CO2). This is probably too high an estimate, given that the IPCC estimates climate sensitivity to be between 3.6°C and 4.5°C. At the low end, that means we need to cap total emissions below 0.661 trillion tonnes of carbon; at the high end, the limit would be 0.484 trillion tonnes. The website estimates that our emissions to date are around 0.555 trillion tonnes.

In the event that actual climate sensitivity is a high but possible 8°C, cumulative emissions of just 0.163 trillion tonnes of carbon would be enough to produce 2°C of warming.

Still, ‘trillionth tonne’ is an accessible concept and it is interesting to watch the numbers update in real time. One especially interesting figure is this one: “We would not release the trillionth tonne if emissions were to start falling immediately and indefinitely at…” At present, their estimate is about 2.1% per year. A higher rate of reduction is necessary if the trillion tonne figure proves overly high.