Posted on 1 April 2015 by Guest Author

This is a re-post from And Then There's Physics

After it being shown that Matt Ridley is benefitting from coal mines on his estate, you might think that he would take a step back and be a little more circumspect in his promotion of the use of fossil fuels. You would, of course, be wrong. His latest is an article in the Wall Street Journal arguing that fossil fuels will save the world.

It’s quite a remarkable article that essentially seems to be arguing that fossils fuels are not even close to running out, that renewables/alternatives are not going to be competitive for a long time, and that because we need energy in order to progress economically, fossil fuels are – and will be – the way forward. In some sense, he may well end up being right; fossil fuels are very efficient, produce energy very easily, and may well end up being the dominant energy source for years to come. The question is really whether or not this is the best way to proceed. To be fair, Matt Ridley does ponder this issue, saying

To throw away these immense economic, environmental and moral benefits, you would have to have a very good reason. The one most often invoked today is that we are wrecking the planet’s climate. But are we?

As you might imagine, he concludes that the answer to his question is “no”. His justification for concluding this is what I thought I might focus on here.

Matt starts with

Although the world has certainly warmed since the 19th century, the rate of warming has been slow and erratic. There has been no increase in the frequency or severity of storms or droughts, no acceleration of sea-level rise.

I don’t know how he defines “slow”. Over the last century, we’ve certainly warmed more than at any time in the last thousand years, or even longer. There’s certainly been an increase in the intensity and frequency of extreme precipitation events. Sea level rise is certainly accelerating and, in fact, it was recently suggested that sea level rise is accelerating faster than we had previously thought.

Matt then goes on to say

Arctic sea ice has decreased, but Antarctic sea ice has increased.

So what? Increases in Antarctic sea ice doesn’t somehow cancel decreases in Arctic sea ice. Also, if you consider volume, rather than area, the increase in Antarctic sea ice volume is probably occuring about ten times slower than the reduction in Arctic sea ice volume. Furthermore, if you consider land ice, its losing mass at an increasing rate.

Matt then claims that

[a]t the same time, scientists are agreed that the extra carbon dioxide in the air has contributed to an improvement in crop yields and a roughly 14% increase in the amount of all types of green vegetation on the planet since 1980.

Possibly, but most scientists agree that if we continue along a high emission pathway, the impacts will likely be severe.

Matt Ridley then goes on to say

Only in the 1970s and 1980s did scientists begin to say that the mild warming expected as a direct result of burning fossil fuels—roughly a degree Celsius per doubling of carbon-dioxide concentrations in the atmosphere—might be greatly amplified by water vapor and result in dangerous warming of two to four degrees a century or more. That “feedback” assumption of high “sensitivity” remains in virtually all of the mathematical models used to this day by the U.N. Intergovernmental Panel on Climate Change, or IPCC.

Well, he’s wrong that there is an assumption of high sensitivity in the models. The feedbacks, and the resulting sensitivity, is an emergent property of the models, not something imposed upon them through some kind of initial assumption. It’s certainly true that there are assumptions in the models that may influence the resulting feedback effect and the resulting climate sensitivity, but that’s not the same as there being an assumption that climate sensitivity is high.

He then continues with

And yet it is increasingly possible that it is wrong. As Patrick Michaels of the libertarian Cato Institute has written, since 2000, 14 peer-reviewed papers, published by 42 authors, many of whom are key contributors to the reports of the IPCC, have concluded that climate sensitivity is low because net feedbacks are modest. They arrive at this conclusion based on observed temperature changes, ocean-heat uptake and the balance between warming and cooling emissions (mainly sulfate aerosols). On average, they find sensitivity to be 40% lower than the models on which the IPCC relies.

Well, it’s true that there have been recent papers suggesting that climate sensitivity may be lower than some other estimates suggest. However, these new estimates do not rule out that the transient response may be close to 2K and that the equilibrium repsonse may exceed 3K. It’s one thing to increase the possibility that climate sensitivity may be low, but it’s another to use that to argue that we should essentially ignore that it could still be high. Additionally, these estimates rely on assumptions that suggest that these estimates should be treated with caution and that – in fact – they can’t really be used to claim that the other estimates are somehow flawed/wrong.

Matt Ridley even says

the warming rate has never reached even two-tenths of a degree per decade and has slowed down to virtually nothing in the past 15 to 20 years.

Well, if you use the skeptical science trend calculator and consider the period 1984-1999, the trend is 0.26 ± 0.151 K/decade, so Ridley is wrong that it has never exceeded two-tenths of a degree per decade. Also, if you consider the past 20 years, it is around 0.1 K/decade. Yes, it has slowed down since then, but it is probably still warming at more than 0.05K/decade.

So, it’s one thing to argue that we should continue to drive economic growth through the dominant use of fossil fuels; it’s another, though, to justify this using arguments that are – at best – flawed and – at worst – completely wrong. There are two basic things that annoy me about the kind of argument that Matt Ridley makes. One is simply that the possibility that climate sensitivity might be low, does not mean that we shouldn’t consider the consequences of it being high. You don’t do a risk analysis by arguing that everything might be fine. The other is the issue of irreversibility. As Bart Verheggen points out

many changes in climate are not reversible on human timescales.

So, yes, fossil fuels have been an amazingly successful energy source that has done much to drive incredible economic growth. Yes, reducing our emissions and trying to change to some other kind of energy source is not going to be easy. Physical reality, however, doesn’t care if it’s difficult or inconvenient. If we make the wrong decisions now, there may be little we can do to correct this if (more likely, when) it becomes obvious that we should have chosen a different path forward.