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Posts from November 2011

Thinking about climate change

Wednesday 23rd November 2011

Climate change is a significant topic that affects the lives of pretty much every living human. As such, discussions about the subject can often get quite heated, with two distinct camps. One side says that climate change is caused by carbon dioxide emissions, and that the consequences for humanity will be absolutely dire. The other side seems to claim that the climate isn’t changing, or that the other side are making things up. To stoke up their claims both sides resort to bad science, misrepresentation of good science, and lots of good old ad hominem attacks. Here are a few things which we know to be true, at least as far as we can be sure about these things:

  1. Climate is changing. It always has, it always will.
  2. Global temperatures have risen.
  3. CO2 levels in the atmosphere have risen in the last circa 200 years, driven by industrialisation.
  4. CO2 is a greenhouse gas. Its presence in the atmosphere does have a warming effect (we’re dependant upon this for our survival!)

Sensible discussion of the topic has to start from at least these facts, as they represent the state of our current knowledge. It is ridiculous to claim that any of these 4 are untrue, because as far as we know all the evidence suggests that they’re not. But equally, sensible discussion of this topic cannot simply stop here. Because these facts raise some questions which need to be answered before we can devise any meaningful response to this issue:

  1. To what extent does CO2 cause changes in temperature? If there is x amount of CO2 added to the atmosphere, what is the corresponding change in temperature?
  2. To what extent is this a problem? What is the cost of doing nothing to stop climate change?
  3. If we can find ways to reduce/stop CO2 emission, what are the costs of doing so?

To think about those three questions, I’ll break them down into the appropriate subject areas. Question 1 is about the science, about working out what’s happening with the climate. Question 2 is about how we can deal with the effects of climate change and the cost of doing so, and so is really about engineering. And the heart of the third question is about reducing the reliance on energy sources which cause CO2 to be emitted (as energy use is the principal cause of CO2 emissions).

Science

When we’re talking about climate, we’re talking about a huge, chaotic system. To start to understand how it works, we’re talking about modelling the flow of fluids (namely water and air) across the entirety of the Earth’s surface, taking into account countless different variables and the way they interact with each other. This is really hard to do, at least with any accuracy. And it’s really hard to look at such a system and to derive the effect that one particular variable has (namely CO2 concentration). So to come back to the first question I posed. Do we know the extent to which CO2 causes warming? No, we don’t. We can run all kinds of models to find some sort of estimate, yes, but finding out whether that model is accurate is not a trivial problem.

There’s lots of confusion about this, it seems. One side of the climate debate tries to make out that climate change is caused by anything but the activities of mankind, whilst the other is pretty set on the idea that it’s all down to CO2. Both sides vilify the other, and that doesn’t really make any sense. We can’t yet say – with any certainty – what effect the CO2 generated by our activities is having on the environment; but CO2 is a greenhouse gas, so it really isn’t a leap to say it’s having some effect.

A good example of this problem can be found when we examine the temperature change over the last decade, and compare it with the change in CO2 concentration in the atmosphere:


Temperature data are global averages from the HadCRUT3 dataset of temperature records. CO2 concentrations recorded at Mauna Loa Observatory, Hawaii.

The basic theory is that CO2 is causing mean temperatures to increase, and yet looking at the above graph, it’s rather hard to find such a relationship. HadCRUT and BEST both show that there has been no warming in the last decade (in fact, the HadCRUT data used here show that mean temperatures have decreased very slightly), even though CO2 concentration has steadily increased. More than likely, we can’t draw too many conclusions from this; 10 years is quite a small period of time when discussing climatic events which take place over a significantly longer amount of time. But at the very least, it causes us to question the claims about the significance of CO2. Because if CO2 really is as dangerous as we’re told, has such a dominant effect that we need to make drastic steps to reduce the amount we emit, we really should have seen accelerated warming in this period.

Now, for the sake of clarity, I am most definitely not saying that CO2 does not cause warming at all; simply that we haven’t properly quantified the warming effect that’s caused by our CO2 emissions. And that, whilst the temperature rose during the 20th century, we probably don’t know the whole story of why that happened; most likely it’s been caused by a number of things, and human activity could be a large or a small component (for instance, we know that solar activity has increased during the last few decades). Climate is variable, it always has been and it always will be, and so there isn’t a steady baseline to make comparisons from. We can’t say that CO2 and temperature have both risen, therefore increased CO2 has caused the temperature rise; it simply isn’t that straightforward. And it’s rather foolish to dedicate lots of resources to the cessation of CO2 emission, when we don’t know whether that really is causing unnatural climate change.

Engineering

So. For the sake of argument, let’s ignore everything I’ve just said. Let’s make the assumption that CO2 is driving climate change, and that if we continue to pump it into the atmosphere it’ll cause a global temperature rise that will cause the environment to change. How could we deal with that?

Fundamentally, this is a problem about the maintenance of the natural and built environment. That’s not a new issue, we’ve been doing this for millennia, and engineers have been doing it using a scientifically rigorous approach for centuries. It’s what Civil Engineering is all about, and we’ve gotten pretty good at it by now. So, let’s look at one particular issue that is likely to be a problem, should global temperatures continue to rise: higher sea levels.

The first step in solving an engineering problem is to work out what exactly the problem is, so we’ve got to find out how much the sea is likely to rise. At the moment, the consensus seems to be that the sea level will rise between 75cm and 2m in the next 100 years. It’s quite hard to visualise what that looks like, what that really means for us. Happily it’s quite easy to model this, to see which bits of land will be flooded after a given change in sea level:


Map of British Isles with 2m rise in sea levels. Areas of land which are below the increased sea level are shaded blue. Source: geology.com.

Not a particularly significant change, actually. The worst-affected area is landlocked anyway, so I guess it might not be encroached by the sea, although flooding may become more likely. But if we really wanted to, these are problems which we can easily solve. If a place is under threat from a 2m sea level rise, then we can build a dyke (or similar) to stop it from being flooded. If flood risk in a region is increased, then there are lots of techniques we can use to deal with that too. Or, in some cases it might be best to simply move away from the areas which are likely to flood, as there’s still plenty of higher land left. None of these approaches should really be that costly, certainly in comparison to some of the alternatives.

These problems can be solved, and in many cases are already being solved. It’s also worth mentioning that on the global scale, climate change might actually cause positive effects in some locations, for example by moderating the climate of places which are currently very cold. And so when we examine these issues to try to think about how to deal with the possible effects of climate change, it quickly becomes apparent that this is something that we know how to do, and that climate change really isn’t the end of the world.

Energy

Now let’s go even further with our assumptions by saying that we’ve decided that we should try to reduce the amount of CO2 we emit. The largest cause of anthropogenic CO2 emission is the burning of fossil fuels for energy. Therefore to make a meaningful reduction in emissions, we must use alternative sources of energy as much as possible.

Several countries have agreed to targets to reduce their CO2 emissions, and there are several policies which are in place to try to achieve this. Firstly, there are high taxes on CO2 emission, in order to discourage activities which cause pollution. There are also subsidies available for the production of certain (supposedly) sustainable sources of energy – wind power, solar power, etc. – to encourage people to install these facilities. And to try to make current fuels “greener”, a certain amount of bio-ethanol is blended with petrol and diesel used for transport.

There are problems with this: it’s expensive, and often grossly unfair. Taxes on energy affect everyone; directly in the price we pay for transportation, heating and electricity, and indirectly in the price we pay for goods. You might argue that, well, we’re wealthy, and we can afford it. And we probably can. If we think it’s an acceptable trade-off, then we can probably afford to sacrifice some luxuries, or lose a certain amount of investment – and jobs – even with the current state of the economy. It makes life difficult for ourselves, but not impossible.

Subsidies are less excusable. It’s the classic argument that subsidies distort the market and make it less efficient. Which is a good argument; we want to use alternative sources of energy when it’s actually efficient to do so, not just because we think we should, as that simply makes energy more expensive than it needs to be. This is also deeply unfair, as it benefits those who can afford to invest in “green” energy, at the expense of those who cannot. Frankly, I think it’s inexcusable to drive up energy prices for the majority with a scheme to provide cheap energy to the minority who are wealthy enough to buy into the scheme.

On the subject of unfairness, there’s also a broader point to be made. Firstly, we’re telling poorer parts of the world that they need to not emit CO2, but often the only affordable sources of energy available in such parts of the world are those which cause lots of CO2 to be emitted. So in a way, we’re asking less developed parts of the world to stay undeveloped, to stay poor. Which limits access to things like healthcare and education in those parts of the world, and so undoubtedly causes a huge amount of damage (or rather, it would if they all listened to us).

On top of this, we impose “green” policies which directly cause actual damage. For example, the requirement that fuels be blended with bio-ethanol has had the effect of raising the price of some foods. This increased price has meant that some people simply haven’t been able to afford to eat, which is thought to have caused at least 192,000 extra deaths last year. Some of the poorest people in the world are being starved because we want to burn their food to reduce our CO2 emissions. Whatever your views on climate change, that should make you mad.

What should we do?

The point that I’m trying to make is that our approach to climate change needs to be more intelligent. The science is very complicated, and probably not well-understood enough to be the basis of policy decisions which can have profound effects. We cannot say with confidence that we are the cause of the changes in climate that we observe.

Given this, it seems sensible to have a different approach to dealing with climate change: to analyse the costs and the benefits of the situation, to work out what really is the best course of action.

The cost of doing something about the possible threat of anthropogenic climate change is massive, as it calls for a fundamental change in the way we do things. It calls for us to abandon the sources of energy which allow us to access many of the resources we need to maintain our standard of living, and it calls for us to deny poorer parts of the world the opportunity to grow and develop and improve their basic standard of living. That is a massive cost. Given that the modest things we’ve already done have resulted in hundreds of thousands of deaths, it’s scary to consider the possible cost of doing more.

Additionally, the potential benefits of reducing CO2 to combat climate change are comparatively small. All we’d do is avoid a certain amount of engineering work which would be required to adapt to the changing environment. It’s not clear that we’d save all that much; the built environment will need to be maintained in the coming years regardless of climate change, and so all we’d do is change the parameters of problems that need to be solved anyway. But solving those problems becomes infinitely easier if we maintain our access to cheap, abundant energy.

Fundamentally, it seems to me that our response to the possible threat of anthropogenic climate change is wholly disproportionate. We’re causing more harm than we could ever hope to stop; we’re spending lots of money (and causing lots of deaths) for solutions that might not work, for a problem that probably isn’t that severe. Whatever way you slice it, that isn’t an intelligent trade-off.

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The Eurozone

Wednesday 2nd November 2011

It’s a bit like a bad joke at the moment.

Last week, the Eurozone leaders announced their latest agreement to save the Euro. Essentially, what they announced was what it is that they’d like to do, but they haven’t really worked out the details of how they’ll do it. It’s only small details that are left to sort out, for example where exactly the money is going to come from…

So they haven’t really agreed much at all. And the stuff they did agree, doesn’t even solve the underlying problem. So for the umpteenth time, the EU leaders have just kicked the can down the road.

Straight after it was announced, some people were sort of facetiously wondering how long it’d take before the plan would fall apart. As it turns out, less than a week! Because the Greek leaders have decided to have a referendum about whether to sign up to the plans. EU leaders aren’t used to the concept of people having a say on Europe, so this has perplexed them. And everyone is worried that when the referendum takes place next year, the Greek voters will give the wrong answer.

Meanwhile, Greece is on track to have a primary surplus by 2012. Which will mean they can safely default, and the EU can go screw themselves…

What’s amazing is just how dysfunctional it is. The Eurozone leaders get to ponce around, looking self-important whilst managing to completely dodge the issue, making it all the more likely that the whole thing goes tits up. It would be quite hilarious to watch, if it weren’t all quite so serious.

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