Treebeard's Stumper Answer
Our Hot and Cold House
We set records for rain and drought in Santa Barbara in the last decade. There is growing scientific consensus that global warming is real, at least partly caused by the CO2 emissions from burning fossil fuels like the gas in our cars. But how can this be when we still have such extreme blizzards (and drought) across the country? Maybe weather is random, like getting 8 heads in a row when flipping coins? My stumper is not to find the answer to global warming, but to pinpoint the question. Why is this topic still so controversial even among scientists?
Is this what global warming looks like? That's Mojo and my son Ry in the hot tub after we worked all afternoon to clear a path through the broken oak trees that blocked our road. (See my Storm Damage (26 March 1999) stumper.) Does it make sense that global warming would bring extreme weather like this foot of snow at our home in the Santa Barbara mountains in March, 1999? Then we had one of our driest springs ever in 2002. Is record breaking weather on the rise?
What's the connection between global warming and extreme weather? President Bush rejected the 1997 Kyoto Treaty intended to reduce CO2 emissions, and he's still hearing about it even from allies like British Prime Minister Tony Blair. Why is this topic still so controversial among scientists as well as politicians?
The last ice age ended only about 12,000 years ago, so of course there is real global warming. Warm air is more energetic and holds more moisture, so maybe we should expect extreme weather. Are we making it worse by burning fossil fuels like the gas in our cars? Economic costs make it attractive to deny, and clashes over values and policy - as well as science - make it controversial. We debate abortion, though "making babies" is well understood. Global warming is more interesting because the science is not all known, but the only time to act might be right now!
I should know better than to tackle this impossible stumper. Of course I can't answer anything here, but I can try to sort out some of the reasons why global warming continues to be so controversial.
- I believe the basic fact of global warming is no longer in dispute. According to the Intergovernmental Panel on Climate Change (IPCC) Climate Change 2001 and the EPA, the Earth's surface temperature increased about 1°F (0.6°C) over the last century. Increased human-generated or anthropogenic greenhouse gases, especially CO2 from burning fossil fuels, are a significant factor in this. Greenhouse gases trap heat on the Earth, like snuggling under a blanket There is growing scientific consensus that this global warming is real, and human activity is a factor. This is where the controversy begins, not where it ends.
- Warming by 1°F (0.6°C) over the last century doesn't sound very impressive. The IPCC projects further warming of 2-10°F (1.4-5.8°C) by the year 2100. That seems like a huge uncertainty with very different consequences at the extremes.
- It seems that low temperatures are rising more than high temperatures to bring up the average. This can mean earlier planting times for farmers. Is that a bad thing?
- The last glacial epoch or ice age ended only about 10,000 - 15,000 years ago, bringing us into the Holocene age. (That means "alluvium", because there's lots of it, but I always think of T.S. Elliot!) This is sometimes called the Anthropogene, the "Age of Man". Look around and there it is. Humans spread across the planet during this warming climate. Our success and history as a species is tied to the changing climate. Asians crossed the Bering Strait to become Native Americans. The Sahara grassland became desert during this time of global climate change, but human visitors left their rock art pictures of their way of life and the animals that have since vanished beneath the desert sands. Maybe the Black Sea really is the Garden of Eden. With our history, we shouldn't be surprised that climate is naturally variable over long periods of centuries and millenia, and generally getting warmer. Climate change has been good for our species, but what's next?
- The whole concept of "taking the Earth's temperature" is puzzling. Where do you put the thermometer?
- We only have detailed weather records for the last 100+ years or so. Many of these records probably reflect the "urban heat island" effects of cities. Longer climate records are becoming available with the study of deep ice cores, melting glaciers and sea ice, lake sediments, tree rings, peat and coral reef deposits, tide levels, etc., but the evidence is all indirect. This is important science work.
- There have been interesting reports of early flowering times and pole-ward migration of several biological species. Julie and I saw Chamise and Toyon flowering on a February hike at the Arroyo Hondo Preserve in the Santa Barbara foothills. I think of these as early-summer shrubs, but I live on top of the mountains, so maybe my expectations are wrong? Past records are not very good, so are these reports really significant? Natural populations are always changing, so this raises many of the same questions. For me, this is still the most interesting evidence for climate change.
- Most of the Earth is ocean, and we don't have good historical records. Now we have satellite monitoring. But without better historical records, it's hard to make conclusions about global warming and large-scale effects like El Nino.
- Major storms and drought are definately getting more expensive. That's not surprising with the rapidly growing population, but it doesn't mean that weather is getting more extreme. The Colorado snowstorm last week was "the state's worst snowstorm in 90 years" (here). So 1913 was worse?
- Climate is different from weather. Weather is what happens day by day at a particular place that is sometimes wet, dry, hot, cold, windy, foggy, etc. Climate is the long-term average for a region. I have been collecting Santa Barbara weather records on my SB rain page. Based on my records, I can talk about our California mediterranean climate, but I still can't predict the weather next week, and an unexpected summer rain doesn't mean sudden climate change. That's why recent blizzards and droughts and heat waves don't prove anything unless there is a long-term trend that changes our idea of the local climate.
- Weather and climate are chaotic in the math sense of having "sensitive dependence on initial conditions". Small changes in initial conditions can lead to big changes in the outcome. But mathematical models of climate are the only tool we have to look ahead at how climate may change.
- Climate models are limited by complicated feedback loops like these:
- More CO2 from fossil fuels --> more plant and plankton growth --> less CO2 --> less warming
- More CO2 from fossil fuels --> more warming --> more water vapor in atmosphere --> more greenhouse effects --> even more warming
- More CO2 from fossil fuels --> more aerosol and sulfate particles --> more cooling --> status quo
- More CO2 warming --> shut down Gulf Stream --> more cooling in Europe
- Melting icecaps and glaciers --> lower albedo and less heat reflection --> more warming
- More heat --> more heat absorbed by the oceans --> not much change
- The oceans have a huge thermal inertia. The first batch of pancakes always takes longer to cook than the second because you have to heat the griddle. That's why the solstices comes at the beginning of summer and winter rather than in the middle. (See my 15 Nov 1996 stumper.) It's a buffering effect that evens things out and delays the peaks. It could take centuries for the oceans to warm up from global warming. It could also take centuries to cool down despite any policy changes.
- Atmospheric ozone depletion is a different problem, though I think many people have confused the "greenhouse effect" and the "ozone hole" ever since the 1970s, and still do. I believe there is general agreement that ozone depletion is a risk, and that banning chlorofluorocarbons (CFCs) like the freon in spray cans and refrigerators and air conditioners has made a real difference in the world. It is possible to change the global environment by controlling emissions. Hey, it was no big deal!
- Even a simple game like flipping a coin 100 times and counting the longest run of heads or tails shows that we should expect the unexpected. We did a class experiment flipping coins for my World Record Breaking Stumper (28 Feb 2003). Our average longest run was 8 heads or tails in a row and three groups had runs of 15. By the math, we should expect a longest run of about log2(n) heads or tails when flipping n coins. That's the closest power of two to the total number of flips, between 6 and 7 for n=100. I asked a few kids to fake the results, and their average longest run was only 5. Then I went through my Santa Barbara Rainfall Data starting with 1934-1935 as a close-to-average base year. In the 67 years since then, we set five high rainfall records and ten low rainfall records. The closest power of two to 67 is
26=64, and 6 is close to 5 and 10. We don't flip a coin for rainfall, but it's an interesting reminder that we should expect weather records to be broken over the long haul.
- The economic feedback loops are complicated too, including:
- More $$ spent reducing CO2 --> more $$ to develop new technologies --> fewer problems
- More $$ spent reducing CO2 --> less $$ spent on other problems --> more problems
I believe that air and water quality have gotten better over the last few decades, at least close to home. That was money well-spent that created jobs and new industries as well. Incomplete information is a fact of life for both policy makers and scientists, and both need to revise their conclusions as new evidence appears. It's no wonder that calculating the costs and benefits of global warming strategies like the Kyoto Treaty is so controversial. The problem is that it's easier and cheaper to wait for "more research", but the only time to act might be now.
This global warming controversy has me thinking of Pascal's Wager. Maybe it's more familiar as a bumper sticker:"If you're living like there's no God, you'd better be right."Here's part of what Blaise Pascal really said in article 233 of section III of his Pensée's (1660; Trotter translation):"God is, or He is not." But to which side shall we incline? Reason can decide nothing here. There is an infinite chaos which separated us. A game is being played at the extremity of this infinite distance where heads or tails will turn up... Which will you choose then? Let us see. Since you must choose, let us see which interests you least. You have two things to lose, the true and the good; and two things to stake, your reason and your will, your knowledge and your happiness; and your nature has two things to shun, error and misery. Your reason is no more shocked in choosing one rather than the other, since you must of necessity choose... But your happiness? Let us weigh the gain and the loss in wagering that God is... If you gain, you gain all; if you lose, you lose nothing. Wager, then, without hesitation that He is.
This is a remarkable passage for mathematical game theory as well as personal theology. It's easy to see the choices as a game matrix. Choose one from the left and one from the top, and see where they cross:
God exists God does not exist Wager for God Gain all Small loss Wager against God Misery Status quo
Let's try rephrasing Pascal's Wager in terms of global warming:"If you're living like there's no human-caused global warming, then you'd better be right."
"Global warming is a problem, or it is not. But to which side shall we incline?... There is an infinite chaos which separates these... Let us weigh the gain and the loss in wagering that global warming is real... If you gain, you gain all; if you lose, you lose little. Wager, then, without hesitation that global warming is real."
IS a problem
is Not a problem
Wager for Global Warming Better future Small loss Wager against Global Warming Huge problems Status quo
Maybe global warming is such a threat that we must act now despite incomplete knowledge and economic costs. I'm happy with that conclusion. Then I had the thought that the war being waged today in Iraq as I write this (on March 23, 2003) has a very similar logic: America must wage preemptive unilateral war against Saddam Hussein despite the high cost in money and lives, because the cost of not acting is far greater."If you're living like Saddam Hussein is not a global threat, then you'd better be right."
"Saddam Hussein is a global threat, or he is not. But to which side shall we incline?... There is an infinite chaos which separates these... Let us weigh the gain and the loss in wagering that Saddam Hussein is a real threat... If you gain, you gain all; if you lose, you lose little. Wager, then, without hesitation that Saddam Hussein is a real threat."
IS a global threat
is Not a global threat
Wager for War Stability and peace Some loss Wager against War Terrorism and war Status quo
No... Wait... This is wrong... We risk losing much more than "some loss" in this Iraq war... This is about the value of human life and our nation's prestige and future... This gaming strategy could allow anything...
These rude choices all sound so familiar. They squeeze difficult real problems into a simple 2x2 game grid, but there are always more choices. There are problems with Pascal's Wager by all accounts. It has an existential attraction, but you can use it to justify almost anything. That religious-like conviction can blind us to the real human costs and benefits of our actions, even in war when people are dying. We still have to make hard decisions that will effect our lives one way or the other, and the lives of many around the world. Scientists and policy makers both have to make hard conclusions based on incomplete knowledge. We count on them to revise their conclusions based on new evidence. There is growing scientific consensus about the facts of global warming (at least) that must be addressed with more than talk...
As a philosopher/naturalist/science teacher, I'm happy to leave this as a stumper. Global warming deserves a huge list of links, but there are other sites that do that better. Here are a few starting links for your own research:
- The Intergovernmental Panel on Climate Change (IPCC) has the complete Climate Change 2001 report available to read or download at their website. The EPA Global Warming site, the NOAA Global Warming FAQ, and the NOAA Paleoclimatology Global Warming site are important resources with links. The Washington Post Global Warming page has links to recent news stories. There is discussion of the 1997 Kyoto Treaty at PBS and the Global Warming Information Center.
- I found J.D. Mahlman's Science and Nonscience Concerning Human-Caused Climate Warming (1998) an excellent introduction to the controversy. The author is with the NOAA Geophysical Fluid Dynamics Laboratory. There's another short intro here.
- Of course there's controversy. In one corner of the ring, there's Al Caruba's "Global Warming: The Perversion of Science", JunkScience.com, and maybe Skepticism.net. In the other corner, we have groups like the Environmental News Network, Friends of the Earth, GlobalWarm.com, and GlobalWarming.com. President Bush rejected the Kyoto Protocol without a vote in favor of more research and voluntary controls and he's hearing about it at home and abroad. There's always another side. Some states like California are setting their own standards. Judge for yourself.
- Bjørn Lomborg's The Skeptical Environmentalist (Cambridge, 1998/2001) is a serious rebuttal to environmentalist claims, including global warming. Lomborg is an associate professor of statistics in Denmark. His book is literally heavy and packed with charts and footnotes leading to the conclusion that the "air and water around us are becoming less and less polluted. Mankind's lot has actually improved in terms of practically every measurable indicator." I'm not surprised that there is growing controversy about the book and author.
- Along with Pascal's wager, there is Pascal's triangle, matrix, theorem, limašon, etc. There are many links on Blaise Pascal at MathWorld. There's good discussion of Pascal's Wager at the Stanford Encyclopedia of Philosophy and the Internet Encyclopedia of Philosophy. There are more links here, including the Atheist's wager.
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