Answers to questions that I'm frequently asked, on this site, at seminars, or at the coffee shop. Under construction....

If you cannot find your favorite questions, send them in by using the comment option on this page.

Global warming

Do you believe in global warming?

A better question would be: do you believe that human activities have the potential to affect global climate? The answer to that is yes. Let's discuss.

Three important observations have been made. First, the scale at which we are emitting green house gases is large enough to affect atmospheric concentrations. For example, there is a very strong correlation between atmospheric carbon dioxide concentrations and the level of human carbon dioxide emissions. So, no question there. Second, there is clear and mounting evidence that the averaged global temperature is rising. Third, comparing carbon dioxide concentrations over many thousands of years to global averaged temperatures, it appears that temperatures increase at the same time as carbon dioxide concentrations increase.

Looking at these observations, it is tempting to jump to the immediate conclusion that carbon dioxide emissions are causing global warming, and that the globe will continue to warm if carbon dioxide emissions continue to grow. Also, most leading global climate models do predict a temperature increase for increasing carbon dioxide emissions. Now, it is true that these models are not guaranteed to be accurate. Global climate prediction involves many physical processes that have complex interactions. We can certainly not claim that the models are correct, nor that we understand the underlying physics sufficiently well. But, what they do show is that there is a potential that increased GHG emissions affect global climate. That together with the observations made, convinces me that there is a clear risk that our behavior will impact global climate. And the consequences of this impact can be severe. If there is a risk, with potentially severe consequences, we should insure ourselves against it. No question.

By how much will global temperature increase over the next 30 years or so?

We can not say. Maybe a lot, maybe not that much. The physics is too complex to make accurate predictions. But, that does not mean we can just forget about it all together. As I argue above, the risk that global temperatures will rise is there. We can not afford that risk.

Is there anything we can do? Are we not too far down this path to change anything?

The worst we can do is nothing. And yes, I do believe that we can make a difference. There is no immediate silver bullet, but there are various ways to reduce emissions and change behavior: efficiency, renewables such as wind and solar, electric transport, carbon capture and storage, cleaner fossil-fuel production, cleaner coal burning. We need a portfolio of actions. But most of all we need to stop arguing about who is right and who is wrong and accept that there is a risk, and that we should to our utmost to mitigate it.

Fossil Fuels

Are we running out of oil anytime soon?

Nope, we are not. The easy-to-produce oil reserves are declining, but there is plenty of oil to be found that is non-conventional, including heavy oil, shale oil, tar sands. Estimated resources are a couple of trillion barrels total: enough to last us for quite a few decades. This is also a frightening thought: there is oil, it will likely be produced unless we wean ourselves off oil by moving to alternative transport, but both production and consumption of this oil is damaging to the environment.

Can the US become energy independent any time soon?

No, we cannot. I know this is claimed by many a politician, but it is impossible. We currently import over 10 million barrels of oil per day, more than half of our consumption, and mostly used for transport. I'm not a fan of biomass production for ethanol, but even if we did go that way, there is not a chance we can replace our imports with nationally produced ethanol, not in the next few years and not in the next few decades. The only way to make an immediate impact on imports, and reduce our oil dependency is to consume less. High mpg cars, fewer car trips.

Is it true that we are importing most of our oil from the Middle East?

No. Here are approximate import numbers: almost 20% from Canada (!), around 12% each from Mexico, Saudi-Arabia and Nigeria, 10% from Venezuela and the rest from a list of other countries, all supplying 6% or less. Total imports from OPEC countries are around 40%. Surprised that Canada is our biggest exporter?

Renewables

Why are you such a strong proponent of solar energy?

Because solar energy is the most abundant resource, far exceeding any other renewable energy resource we know of. If we develop technologies to capture this energy effectively, we are in good shape.

Is wind cost-competitive?

Yes, now it is, on good sites onshore. Off-shore wind is still more expensive in terms of costs per kilowatthour of energy produced as compared to coal-fired, gas-fired or nuclear power plants. But that is also only if external costs (health effects, pollution) are not taken into account. It's frequently claimed that without tax incentives, wind would not be economical. This is a bit unfair, as ever y energy resource is subsidized, one way or another.