The Free Press reports on a new climate change study, this one focused on the Alberta oilsands. Andrew Weaver and his team at the University of Victoria have analyzed the comparative emissions resulting from world supplies of coal, oil, and natural gas, and from individual sources like the oilsands in particular.
Weaver, a leading climate scientist, expressed surprise over the results. The oilsands, if completely consumed (burned), would produce enough carbon dioxide to raise the global average temperature by 0.36 degrees Celsius. The world’s total oil supply may not even be enough to raise the total temperature by a full degree.
In contrast, the world’s natural gas supply could raise global temperatures by three degrees, while the world’s total coal supplies could raise temperatures by a whopping 15 degrees. Weaver thus concluded, “The conventional and unconventional oil is not the problem with global warming. The problem is coal and unconventional natural gas.”
In a certain context this makes sense. If it comes down to a question of which fossil fuel tap we should turn off first, the answer is clear enough. But there are a number of ways this information can be misleading.
First of all, the values reported in the article consider total emissions from consuming total stocks of each of these fossil-fuel types. But what we really want to know is the rate at which each type of fossil fuel is contributing to emissions, ideally with respect to the amount of useful energy produced.
Natural gas, for example, is “cleaner” than oil, releasing less greenhouse gases when producing the same amount of energy. It simply happens to exist in vastly larger quantities in the world. Coal, on the other hand, is both dirtier and exists in greater supply than oil.
A second concern with Weaver’s comments are that they suggest we do have to choose which fossil fuel we need to focus on eliminating, even though each one is often used for different things. The majority of oil emissions come from vehicles and gas-powered machinery, while coal is usually used to produce electricity, and natural gas is often used for heating in homes. Transitioning away from all of these dirty energy sources can and should be done in tandem, and include building non-coal fired power plants, switching to lower- or zero-emission vehicles, and finding alternatives to natural gas heating.
A third concern actually is noted in the article. This analysis only takes into account the emissions produced from consuming the fuel stocks in question, but extracting, processing and transporting all require energy, and themselves contribute to emissions. In other words, we burn oil and coal in order to run the machinery that digs out more oil and coal. The process used in the oil sands is particularly energy-intensive.
The fact is, even if we were to stop mining or burning coal right this instant, a degree of warming from the burning of the world’s oil, though certainly better than 15 degrees, is not something to sneeze at. When you consider that it could actually be close to twice that, taking into account the greenhouse gases released in the extraction, there’s actually no doubt that the ocean level rise, ecological effects and weather pattern changes will result in a very different world than today.
I can appreciate Weaver’s efforts to give us a quantitative sense of what we’re up against. This information could be critical in policy and even individual consumer decisions (for example, natural gas heating we find is preferable to electric if you’re stuck on a coal-based grid). But I have to warn against focusing on any one culprit to the exclusion of others.
To make a long story short, coal may be a heavy-hitter, but it’s certainly not the only “climate change bad guy.”
Photo credit: Staplegunther via Wikimedia Commons