How much does US oil contribute to carbon emissions? Not as much as you think.

Environmentalists tend to overestimate the contribution of oil to global emissions. But that doesn't mean we shouldn't cut down on our fossil fuel use.

Financial Dependence Can Cause Bias

Generally when I find myself having to clarify my position from a previous column, I find that I did not explain myself as well as I should have. Such is the case with last week’s column Environmentalism is a Profitable Business.

There were several ways in which that column was misunderstood, but I want to be clear that I was not arguing that people are drawn to environmentalism for the money. I believe that in most cases they are drawn to the cause because they genuinely care, but in some cases that has led to the creation of organizations that have done very well financially. Because these organizations often put out misleading information, and due to the fact that some peoples’ livelihoods have become tied into the success of these organizations, I questioned money’s role in the promotion of misinformation.

A friend suggested that sometimes organizations go “off the deep end” because they have large donors who are off the deep end and want their cause promoted. And that would be exactly what I am talking about; an example of money leading to misinformation.

Misinformation for the Greater Good?

Last week’s post discussed misinformation about fossil fuel subsidies. To recap, there was a recent “Twitter storm” in which the message was that fossil fuel companies are wallowing in subsidies of up to a trillion dollars a year. The truth of the matter is that nearly 90% of the subsidies cited were for fuel subsidies for poor people. So I questioned whether promoters of the “trillion dollar story” are unaware of this, or whether they are knowingly misleading people “for the greater good.” But my larger point was whether a problem can be solved if you don’t understand the nature of that problem.

Many environmental organizations focus their efforts on U.S. oil consumption because of its role in global carbon dioxide emissions. I suspect people overestimate that role. So what I want to do here is to quantify that role, because my impression is that they are focusing a disproportionate amount of time and energy on a tiny portion of the problem. (I also wanted to satisfy my own curiosity; the truth is that I didn’t know the answer when I started writing this post).

So the question I want to answer is this: Of the 70 PPM rise in the atmospheric carbon dioxide concentration in the past 46 years, how much of that was due to U.S. oil consumption?

U.S. Oil Consumption & Carbon Emissions – Drilling Down Into the Numbers

While the U.S. does consume a lot of oil per capita — and to be clear I have advocated for policies to cut down on our oil consumption — Americans represent only 5% of the global population. Hence, while our impact may be disproportionate, in total it is a relatively small fraction of the total.

In Global Carbon Dioxide Emissions — Facts and Figures, I noted that over the past 46 years (since 1965), the global carbon dioxide concentration has increased by 70 parts per million (PPM). I calculated that cumulative U.S. emissions over that time frame were 255 billion tons of CO₂ , which would have contributed 18 PPM toward the 70 PPM rise. Certainly 5% of the global population contributing 26% of the total rise in carbon dioxide concentrations is a disproportionate impact.

However, this was the total for oil, coal, and natural gas. Cumulative oil consumption for the U.S. from 1965 through 2011 was 37 billion metric tons. I contacted BP to ensure that my calculations were consistent with theirs, and they indicated that they are assuming 3.07 metric tons of carbon dioxide released per metric ton of oil equivalent consumed.

In the past 46 years, the U.S. has consumed 37 billion metric tons of oil which would have contributed 114 billion metric tons of CO₂  to the atmosphere. Plugging back into our correlation between tons of CO₂  and PPM of CO₂  in the atmosphere (see footnote), we can see that U.S. consumption of oil in the past 46 years contributed 8 PPM of the 70 PPM rise in the atmospheric CO₂ concentration.

On an annual basis, at current rates of consumption, U.S. oil use would be responsible for a 1 PPM increase in the global CO₂  concentration every 5.5 years. Certainly, that’s a measurable contribution, but it pales in comparison to the other contributors. If we could cut oil consumption in half in the U.S. for the next 30 years, it would only make a 3 PPM difference. Global coal consumption — dominated by Asia Pacific with 69% of global demand in 2011 — emits enough CO₂  to add more than 1 PPM to the global CO₂  concentration every single year.

Conclusion: Fighting the Relatively Minor Problem

My point is that we have a small problem and a big problem. Fixing the small problem does not fix the big problem, and yet the resources of these organizations are primarily directed at the small problem. I certainly have not gotten press releases from environmental organizations discussing how they are fighting against rising emissions in China, but I am besieged by emails calling for more support in their fight against the Keystone XL Pipeline.

It’s as if a man goes to a doctor and is diagnosed with lung cancer and an ingrown toenail. The doctor throws all of his time and effort into fixing the ingrown toenail, while the man dies of cancer. Certainly the ingrown toenail may need treatment, but treating it is really irrelevant with respect to the larger problem. That’s not just my opinion — that’s what the numbers indicate. U.S. oil consumption is nearly irrelevant with respect to the big picture, and a lot of time and energy are being spent on a minor part of a much larger problem.

In my next column, I want to look at some of the specific claims around the Keystone XL pipeline and about Canadian oil sands to put those numbers in perspective.

Footnote: According to this analysis, the average amount of CO₂  emissions that causes an atmospheric increase of 1 ppm is 14.138 billion metric tons of CO₂ . The U.S. contribution of 255 billion tons over the past 36 years would then contribute 255/14.138 = 18.1.

Note to readers: I am traveling over the next two weeks, and my Internet access may be spotty. So responses to comments and emails may be delayed.