Dialogue: Climate Change

Environmentalist: Our government needs to get serious about climate change! If the world doesn’t reduce its CO2 emissions fast, the earth will be heading for a climate catastrophe!

Brian: Really? What makes you so sure?

Environmentalist: Of course I’m sure; the science on the issue is settled.

Brian: Settled? So climate scientists don’t disagree with one another anymore? Remarkable!

Environmentalist: Oh, they still disagree about some things. But virtually all scientists agree that the earth’s climate is changing, and that higher CO2 concentrations in the atmosphere, due to the greenhouse effect, will result in an increased global average temperature.

Brian: I’m glad that they agree on those things! It would take a pretty loony scientist to maintain that the earth’s climate remains constant, and a pretty ignorant one to deny the greenhouse effect and that CO2 is a greenhouse gas. But I don’t see how these points of agreement, by themselves, support your statement that unabated CO2 emissions will cause a climate catastrophe.

Environmentalist: Modern industrial activities result in CO2 emissions, which increase the CO2 concentration in the atmosphere, which causes the earth to warm. No real scientist would disagree with this.

Brian: Nor do I. But tell me, how much will the earth warm for every ton of CO2 emitted?

Environmentalist: That’s a complicated question best left for the climate scientists. They’ve built a number of predictive climate models that forecast what will happen to the earth’s climate depending on how much CO2 we continue to emit. They disagree somewhat on the details, but they all agree that unless we cut our CO2 emissions drastically, catastrophic warming will result in the not-so-distant future.

Brian: What are the temperature predictions in these models based on?

Environmentalist: Mostly based on the correlation between increases in atmospheric CO2 concentrations and global average temperature, during the periods of the past where we have accurate measurements for those things.

Brian: Can’t have been for very long then. You would need some pretty good technology to accurately measure those things.

Environmentalist: Don’t worry, it’s been long enough.

Brian: Also, the scientists would have to be careful not to confuse correlation with causation. What if a factor other than increased CO2 caused much of the global average temperature rise that we observed within the last 30 or so years?

Environmentalist: Like what?

Brian: Well, there’s a phenomenon called the Pacific Decadal Oscillation (PDO) which changes phases about once every 30 years, and whose ‘positive’ phase corresponds pretty well with the 30 years of warming we’ve experienced since the late 1970s. If the PDO cycles led to cyclical changes in global average cloud cover, that could affect the climate. That’s one possibility. Also, whatever caused the Little Ice Age (1350-1850, approx) to abate might still be contributing to current warming. And, we should never forget our bright shiny friend in the sky, the Sun. Even minor changes in solar activity could have potentially profound effects on the Earth’s climate.

Environmentalist: Well… I’m sure the climate scientists took all of that into due consideration.

Brian: Why? Because scientists never make mistakes when forecasting the future behavior of complex systems?

Environmentalist: Listen, the best evidence and models currently indicate that there will be significant warming as a result of continued CO2 emissions. Though it’s theoretically possible that this isn’t true, we have to work with what we have at the moment.

Brian: Or we could spend some more time studying the issue before taking any drastic action… But for the sake of argument, I will provisionally accept these scientists’ temperature predictions. But in that case, what’s so catastrophic about a bit of warming anyway? It’s cold up here in Canada!

Environmentalist: Don’t be simplistic. That ‘bit of warming’ will cause more hurricanes, draughts, and flooding due to a rising sea level.

Brian: Will it? How interesting. So the climate scientists have evidence that in warmer periods of the earth’s history, there were more natural disasters? The Medieval Warm Period (950-1250 AD, approx) was disaster-central?

Environmentalist: Well, we don’t have good records of the natural disasters that occurred then. But we do know that in our current warming phase there have been lots of natural disasters!

Brian: And lots of diligent meteorologists to record them and alert journalists to report on them.

Environmentalist: Sure, that too.

Brian: Assuming your climate scientists are right about everything, what would we have to do to avoid this climatic disaster?

Environmentalist: Drastically reduce our greenhouse gas emissions, including CO2 emissions from industrial and transportation activities and methane emissions from agricultural livestock.

Brian:  Methane too? How do we reduce that?

Environmentalist: We have to all become vegetarians.

Brian: Ugh, sounds terrible. I love meat!

Environmentalist: Relax; being a vegetarian is better for you and more humane to animals anyway.

Brian: Nope, still sounds terrible. Anyway, how do we drastically reduce CO2 emissions? Reverse the Industrial Revolution?

Environmentalist: Some more extreme environmentalists might want that, but more moderate ones such as myself see the solution in a green energy revolution.

Brian: So increased use of nuclear power?

Environmentalist: Nuclear is too dangerous! Plants can melt down and the waste is very dangerous and difficult to dispose of.

Brian: Hydroelectric?

Environmentalist: No way! That requires damming natural waterways, thereby destroying habitats for animals and the homes and agricultural land of humans.

Brian: Geothermal maybe?

Environmentalist: Are you kidding? Digging into the earth like that can release dangerous gases into people’s basements and could contaminate aquifers. Besides, the process still results in emissions of CO2 and methane, though less so than for coal, oil, and natural gas.

Brian: Well, what then?

Environmentalist: Solar and Wind power of course!

Brian: But those are very inefficient and expensive ways of generating power, when compared with most other sources of energy.

Environmentalist: Too bad! They’re both safe and sustainable sources of energy! Besides, I’m sure the technology will eventually improve, thus making them more efficient.

Brian: It might, or it might not, it’s very hard to say.

Environmentalist: Well, even if it doesn’t, the sacrifice is worth it. Better inefficient energy sources than environmental catastrophe.

Brian: You know, energy plays an integral part in almost every aspect of our lives, from production to recreation. Mandating that only inefficient energy sources can be used will seriously affect our standard of living in many ways.

Environmentalist: Yes, in order to avert environmental disaster, we’ll have to cut back on some of our superfluous luxuries.

Brian: No, energy is not just used to produce superfluous luxuries; it is used to produce almost everything nowadays. Scarcer energy supplies will mean higher prices for almost everything, ‘necessities’ as well as ‘luxuries’, and a lower standard of living for everyone, whether you are rich or poor, in the First World or the Third World. 

Environmentalist: Well guess what? A climate catastrophe would also reduce the standard of living of everyone.

Brian: It might. But you know, a warmer climate would extend the growing season in many places, and a higher concentration of CO2 in the atmosphere would be better for plant growth.

Environmentalist: Yeah, but a lot of agricultural land would be flooded due to rising sea levels.

Brian: More people generally die of cold-related deaths than they do of heat-related deaths. So a warmer climate would be healthier in that regard!

Environmentalist: Tell that to the people whose cities are flooded…

Brian: Well, it sounds like if what your scientists predict will happen does happen, then some areas of the world will be made less suitable for human habitation, and some more suitable. Is that accurate?

Environmentalist: Yes, I suppose. But a lot of our major population centres were built in low-lying areas, which will be made a lot less suitable for human use as a result of climate change.

Brian: Ok, but would you agree that the greater capacity humans have to adjust to a changed climate, the more the negative effects of any climate change can be mitigated?

Environmentalist: Yes, of course.

Brian: Well, the more resources that we have at our disposal, the easier it will be to adjust to any climate change. Resources could be deployed to build dikes and sea walls to protect our cities against the rising sea level, like they did in the Netherlands. Or, resources could be deployed to quickly build new centres of human settlement in more suitable areas.

Environmentalist: All sounds very expensive to me. Why not just mitigate the threat instead, like I recommend?

Brian: Firstly, the mitigation measures that you propose may well be more damaging to our overall standard of living than just carrying on and making the necessary adjustments if/when a significant climate change does occur. Secondly, even if we did everything possible to ensure that humans didn’t affect the climate significantly, we know for certain that natural forces will eventually result in a significant climate change. So, whether caused by humans or not, we will eventually have to adjust to a significant climate change anyway. As such, we might as well be as well-prepared for it as possible, which means not sabotaging our industrial apparatus by severely restricting CO2 emissions.

Environmentalist: Sounds reckless and irresponsible to me. You are playing with people’s lives you know? You ought to be more careful.   

Brian: My friend, though you won’t recognize it, I could say the exact same thing about the policies that you are proposing. Threatening industrial civilization itself is equally, if not more, dangerous than threatening the Earth’s climate. If there’s one thing that you take away from this conversation, I hope it is that.