There is a lot of confusion about what is known about global climate change. Some "misunderstandings" are deliberate—-some people stubbornly refuse to believe any fact they wish were not true—-but I will leave the dissection of such political controversies to my esteemed colleagues on this blog. Instead I will concentrate on the scientific misconceptions, many of which are due to the loose use of terms or the conflation of similar but distinct ideas.
1. There have been changes in the composition of Earth’s atmosphere over the past 150 years: TRUE. The most famous example is the 20% rise in the average concentration of carbon dioxide (CO2) in the atmosphere over the past 50 years, as measured hourly (!) by the Mauna Loa observatory. The increase in CO2 concentration has been gradually accelerating over time, and the measurements are confirmed by similar experiments performed at remote locations around the globe, from Alaska to Antarctica. Measurements of CO2 concentrations for earlier centuries are available from ice core samples taken from around the world. Together, the ice cores and the direct atmospheric observations show unambiguously that the increase in CO2 began in the mid-1800s after having been stable for a thousand years. Furthermore, scientists have measured the interglacial fluctuations in CO2 levels over a much longer period and current levels well exceed any previously known level for at least the past 420,000 years.
2. Humans have been responsible for increase in CO2 in Earth’s atmosphere: TRUE. We can measure the amount of emissions of CO2 due to changes in agricultural land use and from burning fossil fuels. Data is available for industrial emissions for over two centuries. The figures are consistent with the observed rise in the atmospheric concentration of CO2. Approximately 1/3 of the increase has been due to changes in land use, and the other 2/3 from fossil fuels.
3. Sufficient increase in the CO2 concentration will cause global warming: TRUE. Every single model of global climate change indicates that this is the case, and we have the planet Venus to look at as an example. Scientists differ in their predictions of how much of an increase is required to trigger catastrophic warming, largely due to the existence of many other influences on atmospheric temperature (including solar output, and perhaps unknown factors), and the sensitivity to positive and negative feedback in the system. So we know that a sufficient increase will cause global climate change, but we are not sure quite how much is sufficient. Even the Republican-led EPA agrees.
4. Global warming has occurred over the past century: TRUE. Yes, even the EPA agrees that we know "for certain" that at least 1 degree (F) of global warming has occurred since the 19th century (they also concur with the man-made increase in CO2). All agree that warming has occurred over both hemispheres, and over land and sea. However, large annual and even decade-long variances are quite normal, as are differences in the trends for sea temperatures, and temperatures in the troposphere vs. the stratosphere. You have to look long-term and broadly to see the full trend—but when you do, the trend is unmistakable. Tree rings, ice core samples, and many other scientific methods confirm that the recent, rapid increase in temperature is significant and unusual, at least since the last Ice Age ended, and possibly for much longer.
5. Humans are responsible for the global warming that has occurred over the past century: LIKELY. We have a smoking gun and can see a dead man lying on the ground, but we cannot speak with certainty; we cannot be sure that the global warming we are seeing is due to human activities. The Intergovernmental Panel on Climate Change (IPCC), whose findings are used as the basis for environmental policy around the world, even by the Bush Administration, said early it was "unlikely" that the warming was due entirely to natural causes, and added in its most recent formal assessment report that it was there was now, "new and stronger evidence that most of the warming observed over the past 50 years is attributable to human activities."
6. Global temperatures will rise in the future: VERY LIKELY. Because it is widely believed that most of the current rise in CO2 is due to human activities, because it is known that a sufficient increase in CO2 will cause global warming eventually, and because the projected increase in CO2 emissions over the next few decades from the growing global economy will bring atmospheric CO2 concentrations to sufficiently dangerous levels as determined by virtually every model of climate change, the IPCC predicts there will be global warming of somewhere in the range of 2.2 to 10 degrees (F) over the next century, if nothing is done. There are many possible uncertainties and possible cooling effects that lead to the broad range of predicted temperature changes, and in some parts of the world, the resulting changes in weather patterns may instead induce local cooling—but the IPCC warns that a global, average increase of even the lowest projected size, "would probably be greater than any seen in the past 10,000 years."
7. Global temperature rise will cause ocean levels to rise, increasing hurricanes, and more violent weather: MAYBE. An increase in ocean levels is a very likely outcome--indeed, there are already measurable increases--but none of the other climate changes are certain, because they require better models of weather than we currently can produce. So in case you were wondering, "The Day After Tomorrow" is an amusing but silly film.
None of this has to do with the ozone hole, increasing methane from cows, decreasing trees in the rainforest, loss of species diversity, nuclear power, El Nino, the Arctic Oscillation, or the vast left-wing conspiracy. It's just good science.
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The agreement that there is a global warming problem and that we caused is more and more accepted, as Dr. Strangelove says, even by the Bush administration.
But not much is being done. I think there are two political reasons for this. First, the benefits of solving the problem won't be realized for many years. Second, how we fix the problem has major distributive implications right now. While the whole world would benefit in the future, who pays for the fix today is a nasty little problem.
For example, because of agricultural subsidies in the developed world, developing countries have no choice but to industrialize. Doing so makes them pollute more per person (I think) and per unit of energy consumed (I'm sure) than we do in the developed world. But should these countries be asked to cut back on energy consumption now that they're just beginning to improve their citizens' lives a little?
If the developed world reduced its pollution levels and energy consumption levels would that mean a loss of jobs? It might generate jobs in specialized pollution reduction industries but it would also endanger jobs in other, more established, industries. Who among us would volunteer to become unemployed for the sake the environment 20 or 30 years from now?
What we are all hoping for is that Professor Frink and his lab assistants will come up with some magical technology (like cold fusiion or something) that will cut the political Gordian knot before the coastal regions of Europe and America flood. But is that a realistic strategy?
// posted by Raised By Republicans
RxR asks what can we do to prevent the projected global warming during the 21st century? It's the classic Tragedy of the Commons, a multi-way prisoner's dilemma (doesn't it always come back to that?) Unfortunately, even if we cut emissions now, the concentration in the atmosphere will continue to grow for perhaps decades before it levels off and begins to drop again--so by the time everyone can see the effects, it will be too late to prevent them. The Kyoto treaty, flawed though it may have been, is at least a start in the right direction: a global agreement is going to be needed.
Sure, Professor Frink and his lab assistants may come up with some great sources of energy in the future (fusion anyone?) but I would argue that we've already come up with two magical technologies to solve the problem: solar power and nuclear fission. Other alternative or "renewable" energy sources (e.g. geothermal, tidal, wind, biomass) simply do not offer enough potential.
There's a marvelous lecture on energy you can look at that which shows the potential of various alternative energy sources. I'll summarize it here. For scale, note that in 2000, the U.S. consumed power at a rate of 400 GW (gigawatts), and current rates, we'll need to at least double that over the next 25 years.
Wind: If you covered the ENTIRE land-area of the U.S. with wind farms, you would get 600 GW. An area the size of Ohio would give about 8 GW. Even that is probably infeasible.
Geothermal: If we filled the ENTIRE land-area of the U.S. with geothermal wells, we could get 630 GW. An area the size of Ohio would give about 9 GW. Even that is probably infeasible.
Biomass (plants for fuel, like ethanol): If you covered the ENTIRE land-area of the U.S. with plants grown solely for fuel (not food) we would get about 4500 GW. An area the size of Ohio would give 60 GW. Even that is probably infeasible.
Hydroelectric: If we dammed EVERY river on Earth, the maximum obtainable would be about 1500 GW, but the Earth is already getting 600 GW from hydroelectric (not including Three Gorges and other projects under development), so Earth as a whole only has 900 GW more to exploit. The U.S. share would be much less, since we are only 7% of the Earth’s area and we've already filled out most of our hydroelectric potential. Optimistically, we might get 100 GW this way... but it would devastate our river system.
Solar: If we covered the ENTIRE land-area of the U.S with solar panels, we would get a whopping 180,000 GW (yes, this includes inefficiencies, nighttime, bad weather, etc.) Now we're talking! An area the size of Ohio would yield 2500 GW. We could get the 400 GW that we need for the next 20 years with "only" 8000 square miles of solar panels. Yes, this is an enormous investment, but at least it is more feasible than any of the others so far.
Nuclear: Today's fission plants can produce about 1 GW each. If you want 400 GW, you'd need 400 new nuclear plants. That would be 20 per year for the next 20 years. Even if we had to make 60 per year of smaller plants, it would still be the most feasible alternative.
If we invest in nuclear and solar, we can start slowing down our use of fossil fuels while creating jobs, not destroying them. It's a start.
How much for covering all of Alabama?
// posted by LTG
More serious comment. Does collecting that much solar energy have any other impact on the planet? Would it reduce global warming if, basically, 400GW of solar energy is not being pumped into the earth, but rather expended by us?
"I must say that's a remarkable idea you have there Herr Doktor."
Seriously, great information!!
Of the two most likely (nuclear and solar), I would say that nuclear is limited by the intense political problems. The Not In My Back Yard forces are particularly strong with nuclear power now that FX is making made for TV movies about terrorists turning nuclear plants into giant bombs.
Solar would seem to be the easiest to promote politically. The only people who would lose on it would be energy companies who currently rely on fossile fuels - especially oil and gas.
It seems to me that we could get a huge increase in solar power usage by freeing up the market for power. This is an example of what I mean by market based progressive policy by the way. We could allow individual people and businesses to sell their excess solar generate power back to the grid. Right now, some states allow this and then only under a range of restrictions (aka market distortions) that favor the big energy companies.
If we did this people would have a finacial incentive to put solar pannels on the roofs of their houses/businesses. This would generate a market for production, sale, installation and maintanance of home solar generators (i.e. MORE JOBS). Also by decentralizing the power grid, we would get away from the monopolistic practices of the current power companies who take steps to ensure that there is always a slight shortage of electricity (to maximize the price). If there were millions of potential providers, incentives to buy your home solar unit would go up as demand for electricity went up. And since it would be nearly impossible for millions of home owners to form a cartel, that demand would be met with incresed supply.
So the next time a Republican tells you that being pro-business is the same as being pro-market, ask them about energy policy and ask them why Dick Cheney is so secretive about his meetings on the issue!
// posted by Raised By Republicans
LTG: By absorbing nearly all incoming light instead of reflecting a sizeable portion of it, a large area of solar panels would increase somewhat Earth's net energy intake from the Sun. Of course you are correct that some of that energy will be used up for work, but not all of it--in fact, most of it will eventually be dumped as heat. And furthermore, energy re-radiated as heat is precisely what gets trapped by the greenhouse gases (energy re-radiated as light is much less susceptible to being trapped--the sky effectively transparent to visible light.)
So if the solar panels absorb twice as much energy as the ground would have, and yet half of that energy gets dumped as heat anyhow, then globally speaking, it's a wash.
But to clarify, it would still generate environmental gains because of the reduced green house gases in the atmosphere, right?
Oh, and also my point about cheaper energy by breaking the monopoly.
// posted by Raised By Republicans
My main point in writing this post was to point out that anyone who tells you that (a) greenhouse gases have not increased due to burning fossil fuels, or that (b) there has been no global warming, is quite simply wrong. Furthermore, while there is room to argue that (a) has not caused (b), we know for certain that (a) will cause (b) in the late 21st century (if not earlier) if we don't stop pumping more and more CO2 into the atmosphere--because by then we will have artificially doubled the concentration of greenhouse gases even under the most conservative scenarios. The result, under the most conservative scenarios, is several inches rise in the ocean level, possibly much more.
Figuring out what we should do about this is a whole different issue, but let's at least put a stop the garbage being ladled out on the conservablogs that global warming and greenhouse gases are myths.
Rxr: Yes, any non-Carbon-burning replacement for fossil fuels would reduce emission of greenhouse gases. But please note that even were we to stop all man-made CO2 emissions cold turkey tomorrow, the global temperature would still rise for a few decades until it stablized... only then might it drop.
And I fully agree that making solar (or nuclear, I must add) power cheaper would break the monopoly on fossil fuels except for the need to burn gasoline for internal combustion engines. Until we have hydrogen fuel cells, the need for lots of fossil fuels will still be hanging around. Did I mention that nuclear power provides hydrogen in abudance?
I disagree about the effect nuclear power would have on the energy monopolies. Nuclear power plants are not something anyone would build on a small scale on their own. They require enormous amounts of capital up front as well as expensive security and regulatory expenditures.
Remember the existence of the monopoly is not a result of fossile fuels per se but rather the way the power grid is arranged. So getting rid of fossile fuels would not neccessarily get rid of the monopoly.
The more I think about it (given Dr. Strangelove's great info) the more I think solar is the only way to go, environmentally, economically and politically. We should really push hard for solar (combined with the ability to sell excess back to the grid) and back off of nuclear power.
// posted by Raised By Republicans
An article in the NY Times on M,ay 15th (Sunday) Old Foes Soften to New Reactors discusses why, "Several of the nation's most prominent environmentalists have gone public with the message that nuclear power, long taboo among environmental advocates, should be reconsidered as a remedy for global warming." Sen. John McCain also cited nuclear power as an option we needed to invest in. Just thought it was a remarkably timely article, given my otherwise timeless (?) post.
Nuclear reactors have a number of political problems in addition to general distrust by environmentalists.
What to do with the waste? Who will take it? Nevada? That plan is still generating controversy.
How to guard it and regulate safety. A failure of security or safety at a nuclear power plant is - however unlikely - very very bad.
Solar power has neither problem and generates large amounts of energy. It has the added benefit of decentralizing the power grid which makes sabotage of the grid more difficult and breaks the monopoly of the power companies.
I'm sure John McCain's star power will convince many people to go nuclear. And while I'm not neccessarily opposed to nuclear power, I think it is a second best solution to a problem for which there is a 1st best solution available.
// posted by Raised By Republicans
There was a great article recently (can't find it, but here's another on the same subject ) that states that spring is coming earlier in the northern hemisphere. Animals are emerging from hibernation up to 10 days earlier, migrations are happening earlier, and flowers blooming earlier. This is solid evidence for the idea of the warming of the earth, because the animals aren't fooled by the so-called "faulty measurements" cited by conservatives and Michael Crichton.
// posted by LTG
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