Friday, February 02, 2007

On Global Warming

The Intergovernmental Panel on Climate Change (IPCC) released a report today in which it revealed that it is very confident that humans have contributed to global warming.

Before I get into this too far, I will point out that I am not an expert (yet) on this topic. However, I am interested in the topic and in the reactions you all have to the way other people (the media, politicians, businesses) talk about it.
From what I can tell in the news articles, the IPCC report said 4 interesting things:

1. Global warming is real and significant.
2. It is "very likely" caused by human activity - mainly fossil fuel combustion.
3. There is no way to reverse the effects in the short term. Even if we drastically cut emissions of greenhouse gasses, the average world temperature will continue rising for 100 years or so.
4. The effects will include rising sea levels, increased likelihood of droughts, severe weather, hurricanes, etc.

This is a controversial subject, so it is important to communicate precisely. For me, that's one of the most frustrating parts in all this. When I see news reports or read articles about this IPCC report, the reporters rarely give enough of the actual contents of the report. This seems like it often happens when it comes to global warming stories, or anything politically charged. After giving a quick summary of what the IPCC said (sometimes contradicting other quick summaries from other articles in the process), they jump straight to analysis or quotations from people we haven't heard of who may or may not be interpreting the report correctly in the first place.
I guess that's another thing I should mention. As I have studied more statistics (in the course of my actuarial exam preparation) I am increasingly wary of anyone else trying to interpret statistics.
I will give you a quick example. Suppose that I hear on the radio today that the U.S. GDP in January was up by 3%. What does that mean? It could mean that it was 3% higher at the end of January than at the end of December; or it could mean that the GDP was 3% higher at the end of January than at the end of January last year; or it could mean that GDP growth from the start of January to the end of January was on the pace to be 3% for the year. My point is that you often have to have more information than you are given in the news to properly interpret a given statistic.
Anyway, what I am saying is that when it comes to this subject, I rarely feel like I have enough information to judge anything for myself, even after reading an article or watching a report on it. So here is what I'm going to do. I'm going to list my biggest questions about global warming. I have been wondering about many of these for months or years, ever since it has started becoming a big topic. Feel free to try to answer the questions, or to add some of your own. Then, I am going to go do some research. I'm going to actually read this IPCC report (at least the summary) and anything else I can get my hands on and try to get what information I can straight from the sources. Hopefully I'll be able to answer these after I've done all that. I suspect that I will be able to answer some and debunk the assumptions underlying others, leaving me with some stubborn unanswered questions.
Note: These questions take the viewpoint that the burden of proof lies with those who claim that global warming is real and caused by human activity. Let's say that the presumed audience of these questions is the IPCC.
My questions are:

A. What are the sources of your data? How far back does it go?
Is it from urban areas? Urban areas that used to be smaller when you started taking measurements in the 1800s? Have you taken into account the fact that urban areas tend to heat up as they develop without effect on the outlying rural areas? What's up with the stuff I hear about taking ice core samples? What does that measure?

B. How do you know that this warming isn't just part of a natural cycle?
How do you know fossil fuels are to blame? It's true that we've burnt more in the last 200 years than previously, but there are many things that are different now than they were 200 years ago. Women's suffrage and pogosticks come to mind. How do you know that the relationship between global warming and fossil fuels isn't as spurious as it would be between warming and number of women voters or between warming and number of pogosticks.

C. What about the global cooling everyone was worried about 30 years ago?
Are you all the same scientists that were talking about global cooling in the 70s? If that was just a temporary trend, as it appears it was, why isn't the warming trend also temporary?

D. What can be done to mitigate the effects?
Is the long-term solution just to use less fossil fuels?

E. What about the scientific method?
This is related to some of the other questions. You can't perform climate experiments the same way you can perform experiments in other areas. If we were to design an experiment to test the causal relationship between fossil fuel combustion and global warming, it would have to look something like this:
-First we need two identical earths with identical characteristics, population, etc.
-One will be the control earth which we will simply observe.
-On the experimental earth, we will prevent them from burning fossil fuels.
-Observe for 300 years or so.
Since you haven't done that, how have you come to your conclusions?

F. Could there be any good effects of global warming?
Could this cause a net gain of arable land in the world? Less deaths because of blizzards?


Cabeza said...

Um, Jon, I said parental spanking in California, not global warming. But a rant is a rant, so I'll take it.

First off, let me add to your pile of research. I got the links to these articles from Warren. They make some good points:

On burning carbon into the atmosphere NOT from cars:

On ethanol:

On the behavior of the sun:

I like that last one a lot because it brings up points that nobody else seems to consider, and it addresses you question B. I've been asking myself that question as well. We know that the world goes through periods of warming and cooling. So how much of this is natural? How much of this is caused by us? How do we differentiate between man-made greenhouse effect and naturally occurring greenhouse effect? Nobody (at least in the media) seems to be asking these questions.

I have another point, though. Let's assume that we're not causing the deadly warming of the earth that will end in Florida being submerged (is that really so bad?). Can the hysteria still be harnessed to serve a positive externality? I mean, wouldn't it be nice if you could see the Hollywood Hills when you're in Hollywood? Wouldn't it be nice to drive into Utah Valley on a winter day and not be greeted by brown sky? Cutting back on fossil fuels will still help asthmatics, make for prettier scenery, and help people not loathe Southern California as much. Sure, people are jumping on a fanatic bandwagon, much like those fools who want to ban trans fats, but in the end the fervor for cutting back on greenhouse gases could still be beneficial.

Cabeza said...

The links posted weird so that you can't see the whole thing. But if you triple-click so that the whole line looks highlighted, then CTRL+C and CTRL+V into the URL bar, it should still work.

Cabeza said...
This comment has been removed by the author.
Nick said...

Doh! JonnyF you beat me to the post. I've been trying to study up on the topic and have tried to read papers published in the relevant journals. I don't have time now, but I just want to add one more ranting point (is that equivalent to a talking point?) to you list:

I'm tired of people on both sides of the global warming debate that try to use consensus (or lack thereof) to either prove or disprove global warming. Yes, it is true that the majority of climate scientists think global warming is happening and is human caused. Yes (talking to the opposing camp now) it is also true that there are some very prominent climate scientists who do not think it is happening, or at least do not think it is human caused. When pro-global warming people try to belittle the ignoramuses who deny global warming by using something as petty as peer pressure, that just puts a bad taste in my mouth and belittles the science behind the theory.

I'll post something more substantive later, though I must say I agree with Jared that even in the slight possibility that either global warming is not happening or is not human caused, it is still a GOOD thing that we reduce air pollution. Those of us living in salt lake are considering moving to southern california to escape the inversion.

Nick said...

By the way, here is a link to the ipcc's report. Beware- its long.

Nick said...

Oops- that last link was for the 2001 report. The new report is not "officially" online, though I heard that the bush administration has leaked the full report to the web- though I have yet to find it. They have released the summary for policymakers, though it is greatly watered down.

Julie C said...

Dan received "An Inconvenient Truth" for Christmas - an he actually watched the whole thing. There were a few points that made me laugh - such as the idea that humans could reduce their carbon dioxide emissions to 0 (I need to breath, don't I?). There was also a categorization of human beings:

(a) those who don't think global warming is a problem
(b) those who think global warming is a problem and that we can actually do something about it
(c) those who think global warming is a problem but also think we can't do anything about it

Dan placed himself in the third category - I think I'm in there too. Even if there have been climate changes, they are either (a) natural and not significantly influenced by human activities, in which case we couldn't really do anything about it - or (b) significantly influenced by human activities, in which case it's pretty much too late to do anythingg about it.