Video: “The Evolution of Global Warming Science: From Ideas to Scientific Facts” Warren Washington
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Chris Petersen: Our next speaker is Dr. Warren Washington, a Senior Scientist and Head of the Climate Change Research Section in the Climate and Global Dynamics Division at the National Center for Atmospheric Research. We are proud to note that Dr. Washington earned a bachelor’s degree in physics and a master’s degree in meteorology from Oregon State University, followed by a PhD in meteorology at Pennsylvania State University. Washington’s areas of expertise are atmospheric science and climate research and he specializes in computer modeling of the earth’s climate. Washington held the office of President of the American Meteorological Society in 1994 and for 12 years served on the National Science Board, which provides oversight over the National Science Foundation and advises the executive branch in Congress on science related matters. From 2002 to 2006 Washington served as Chair of the National Science Board. You should also note that Dr. Washington published his autobiography last March and it is available in all the usual places, such as Amazon. Dr. Washington’s talk is titled "The Evolution of Global Warming Science: From Ideas to Scientific Facts." Please join me in welcoming Dr. Warren Washington. [Applause] [1:23]
Warren Washington: Thank you very much. It’s quite an honor to be here and I’m going try to make some of the connections between Linus Pauling and climate change, although I don’t think he actually did any research directly in this area. I also want to touch on the issue of science policy which, of course, he did have a lot of influence on. I’ll be speaking about the history of understanding climate change and global warming and some of the early thinkers. Also, I will talk about how we can place limits on global warming by adopting new energy strategies that are less dependent on fossil fuel. This will limit how much global warming will occur by the end of the next century. Clearly, this is an intergenerational problem. At the end of my talk, I will say a few words about the parallels between Linus Pauling and Al Gore on the issues of the political action. In the upper left-hand corner of my slide is one of the early thinkers about global warming, and that’s Joseph Fourier, who actually carried out some early calculations about the fact that terrestrial radiation energy can be absorbed by the various gases. He did not really talk about global warming, but he just came up with one of earliest ideas about absorption of infrared radiation in certain gases such as carbon dioxide and water vapor. The next person was John Tyndall who actually built some laboratory experiments that took into account the absorption in water vapor as well as carbon dioxide and he made some inferences about how this might influence the earth’s climate. If you had little or no greenhouse gases on a planet, then you would have a much colder climate. Tyndall was able to foresee some of these early ideas about how the climate maintains a specific temperature.
Note Svante Arrhenius is in the lower left hand corner of the slide who, like Pauling, received the Nobel Prize in chemistry. Arrhenius actually did some calculations that were relevant to climate change where he estimated that if you doubled the carbon dioxide in the atmosphere, the atmosphere or climate system would warm up by 5 to 7º C, which is pretty close to what we find with our more realistic climate models. However, I should note that almost all of the assumptions he used were wrong, but he got the right answer. Arrehenius’s overall concern was over the growing use of coal and other fossil fuels and whether they would change the climate. Another person who had early ideas was T.C. Chamberlin in 1896, who speculated about the effect of carbon dioxide variations as being causes for going in and out of ice ages. I believe Chamberlin started some of the early thinking about the carbon cycle and how much was stored in the atmosphere,the ocean, vegetation and the terrestrial biosphere. However, it was all qualitative; he didn’t have any measurements of any significance. [6:19]
At this point, scientists were only dealing with the quantitative effect of all of these ideas. In about 1938, Callendar, who was actually an engineer, had a hobby of dealing with the weather and the climate. He did some calculations with a very simplified model and became alarmed about global warming and believed that we really need to start cutting back on fossil fuels. Again, his work was marred by the fact that we didn’t really have good measurements of what was going on in the atmosphere. In the lower left hand corner of slide there was new measurement started at the end of the International Geophysical Year (IGY). There was some extra money at the Scripps Institute of Oceanography and they hired a physical chemist who did something quite remarkable. He was dedicated to finding out how much carbon dioxide is actually in the atmosphere. Up until that time, the measurements of carbon dioxide were quite imprecise, in fact the measurements inaccurate by factors of two in some cases. What Dave Keeling, the physical chemist, did at Scripps was to set out to actually measure carbon dioxide from air samples from Mauna Loa, Hawaii. He devised a more accurate method of detecting carbon dioxide concentrations. What came out of this research was the famous Keeling Curve which showed a year to year increase of carbon dioxide concentration. In fact, if you exaggerate the upward trend of carbon dioxide as shown in the subsection of the figure, you can see a seasonal cycle. These were the first accurate measurements of carbon dioxide concentration. [8:25]
The rate of increase was very alarming to many of us scientists because all the efforts that were put forward in the last few years have not resulted in a tapering off of the increase of carbon dioxide. [9:30]
Here, I want to point out the global surface temperature trends, and these graphs are from the NASA GISS group, but there’s also two other groups around the world - one in England and one in the NOAA that have generated similar global surface temperature trends. You can see in all three of them a substantial warming from 1880 until the present. Something of the order of 0.8 or 0.9 degrees centigrade is a very rapid increase of temperature. I don’t need to tell all of you that the glaciers are melting over virtually all parts of the world, with the just a very few exceptions, and this rate of rapid melting of the glaciers seems to be accelerating. In fact, there will be some parts of the world where people who are dependent on glaciers, like in the Andes, for freshwater are not going to have substantial amounts of freshwater in the future. [11:15]
This figure is actually from recent IPCC Assessment Report number 4, but I wanted to just give you some idea of the various factors that we can identify from observations. Here we see the observed carbon dioxide concentrations measured after 1957. The earlier values of carbon dioxide before 1957 are obtained from glacier ice cores where the ice has actually trapped air inside from previous time periods. These same air samples also show changes in methane. Sulfate aerosol particles goes through a very interesting period where it was fairly low, and then it increases, and then it actually went down because of the air pollution controls. It is also possible to infer the changes in surface temperature going back in time over hundreds of thousand years, however, there is some uncertainty about how far you can go back with fairly accurate measurements. The instrumental records are shown on the slide in red; all the others come from tree rings and other proxy data sets. If you look at the projection from the models, we’re indicating that by the end of this century, we’ll go from a two degree up to a six degree increase in temperature. And so this will be a remarkably large increase compared to the last thousand years. [13:33]
Now, I’d like to shift a little bit and talk about computer modeling of climate change. This is a little bit closer to what I’m involved in. On the left of the slide is V. Bjerknes. In 1904, Bjerknes actually wrote a paper on how you could solve the mathematical equations that governed the flow of the atmosphere - and in principle, the ocean, and the climate. In principle, this set of equations governs the weather and climate systems. He didn’t attempt to do that because those equations are non-linear partial differential equations involving space and time, so you need to have a way of actually doing that and computers weren’t available then. [14:31]
The gentleman on the right is L.F. Richardson and he has some parallels to Linus Pauling in the sense that he was a Quaker who lived in England and didn’t want to take a military part in World War I, so he volunteered to be an ambulance driver in France. He took it upon himself to actually do a weather forecast by hand. Now, it wasn’t quite by hand; he had a little hand mechanical calculator. During the WWI episodes, wars were quite different than now. In those days everyone waited around, idle most of time, for battles to happen so he had lots of free time and he actually carried out a calculation for a small area over France, solving the massive set of equations. Now, he took into account virtually everything. He took into account the dew on the grass and the evaporation off of vegetation. His forecast was a failure in terms of accuracy, but he set forth the methodology that we all use now as we make weather and climate forecasts. He wrote a book about it and included every step in the process. It is interesting to note that we present day climate modelers are applying, in one way or another, all of concepts that Richardson mentioned in his famous book. For example, he imagined having an orchestra theatre where he would have everyone with a hand calculator doing some part of the calculation and he would be in the orchestra pit with three different flashlights. If someone was going too fast he would put the red light on them and they would slow down their calculation, and then if you were going too slow he would shine the green light on them, and he would shine a yellow one to caution someone to keep them at the pace of your nearest neighbors. So he really anticipated the idea of parallel computers. Now, because his calculation was so enormous and so difficult, no one tried it again until John Von Neumann and collaborators came along and put together a team at Princeton University’s Institute for Advanced Study which developed one of the first electronic computers. This group used a simpler model than Richardson to make the first short range weather forecast which was very successful. This started the building of weather and climate models. [17:36]
I want to briefly mention something about the development of climate models. At the time I started in 1964, we were working with separate atmospheric and ocean models. They weren’t coupled to each other but they were under development. Computers were very slow then, so we had to simplify the models greatly in terms of what kind of physical processes to include, and we had to have very coarse resolutions because the computers just wouldn’t handle higher resolutions. There were only small teams. On the team that I was involved with, it was only 4 people at a major national center. Now I’ll skip over to the far right of the slide and you can see atmospheric and land surface and vegetation models are going forward, ocean models, sea ice models, you couple all these models. You even include things like sulfate aerosols, which are very important for reproducing the effects of air pollution and volcanic eruptions. In addition to carbon cycle, we have dust and sea spray and carbon aerosols, interactive vegetation - in other words the vegetation can change if the climate changes. We include other biochemical cycles such as the nitrogen and the methane cycles. Presently, we are putting into our models ice sheets dynamics and thermodynamics because ice sheet changes are very important in determining sea level changes. People want to know how much sea level is likely to change in the future. The next slide shows a schematic of what’s in the present day climate models. We go all the way from incoming solar radiation, where we have interactions with various cloud types such as stratus clouds and cirrus clouds, which are the very high clouds. Now I might point out there has to be a balance in between the incoming solar radiation and the outgoing infrared radiation at the top of the atmosphere, and right now the climate system is out of balance because of the increased anthropogenic carbon dioxide. So we don’t have on that balance right now. Its a few watts per meter squared globally averaged different than zero.
I won’t go through every one of the aspects on the schematic, but we include snow cover, soil moisture, rivers, ocean circulation, sea ice, marine biology, precipitation and so forth. All of these are integral parts of a state-of-the-art climate model. [21:08]
If you look in the upper left hand corner, you’ll see very coarse resolution for the ocean as well as over the land and as we go to the bottom right you can see the resolution has improved significantly, so the mountains and coastal representations are a lot better. You can see that even in our next IPCC assessment, we will have more realistic horizontal resolutions in somewhere around ten to twenty kilometer squares, whereas in the early days we had five hundred kilometers. This is made possible by making our climate models work on thousands of computer processors, all at the same time. Imagine these processors working on various parts of the world’s climate system. Here I want to point out that we even include some of the natural forces, such as climate forces by the Mt. Pinatubo eruption which occurred in 1991. When we put in the effects of carbon emissions into the atmosphere we get global warming. Here is a schematic from Time magazine, 2001. Now, I might point out that in 2001 the U.S. was the largest emitter of carbon dioxide; however, now China seems to be emitting more carbon dioxide into the atmosphere than the U.S. They are building a new coal fired power plant every week. So, you can imagine that there’s going to be a great increase in carbon dioxide concentrations in the atmosphere. Now, I’m going to skip through this next slide fairly quickly. This is a neat plot that I got from a paper in the Proceedings of the National Academy of Sciences. If you look over here you can see populations. The U.S. is dark red. And if I look over here in the left hand side you will see that most of the accumulative emissions of carbon dioxide are caused by the U.S. We are a big accumulative emitter. If you look at Europe, which is in orange, and go over here you can see that Europe and the U.S. are the primary cause of the present level of concentrations of carbon dioxide. Now I might point out that when you burn a fossil fuel, whether it is coal, natural gas, or oil, that that newly generated carbon dioxide molecule has a lifetime of the order of a hundred years and some of those molecules will have a lifetime of five hundred years. So it’s not the type of pollutants that you put in the atmosphere that get washed out in a few days. Carbon dioxide has a very long lifetime and we have to take that into account. But anyway, you can see that the developing countries, for example, have very large populations but their emissions in total are relatively smaller than Europe and the U.S. I hope this gives you an idea of who’s actually contributed to the existing global warming. [25:08]
I want to show an animation of globally averaged surface temperature from 1870 to the year 2100. Note the cooling effects after each of the volcanic eruptions. As the animation goes into the future, you see the climate system is warming. The top part of the animation shows the geographical warming pattern. Note the year to year variation where there is lots of climatic noise, but over time, the climate system becomes warmer. Most of the warming takes place over the Arctic and over the continental areas. We carried three different scenarios for the IPCC in which the A2 scenario is the largest and close to business-as-usual. [26:38]
This slide shows what the climate is likely to look like at the end of the twenty-first century. You have been reading these stories in the media about a very large sea ice decreases in Arctic sea ice. I believe the experts are estimating that the 2007 summer time is the lowest on record and that by 2040 or 2050 there will be virtually no sea ice at the end of the summer season. [27:12]
Let me skip through this fairly quickly because of limited time. What can we do about the future? The Europeans have set, as a goal, that we should only have two degrees warming from 1870 until the year 2100. We work closely with the integrated assessment scientists. They are experts in energy, economics, and land surface changes that could affect the carbon cycle. They look at different parts of the world, in this case fourteen regions, and they actually generate future emission scenarios based upon certain assumptions and projections of how things can go. Usually the integrated assessment experts give the climate modeling community high and low emissions strategies as shown in slide on the left hand side. We often show our results in averages for December, January and February and June, July, and August. Also, we show a low emission scenario and a business as usual scenario. So the world has in its power the capability of deciding if we are going to have a low energy strategy - in other words, use more renewables, even nuclear energy, or conservation, to prevent significant future climate change? I think that we have that in our power. The public seems to have woken up about this. As for mitigation and adaptation, we’ll probably have to do both. We will continue to develop earth system models that will show us how we can cause less harm to the environment. There will be a sustainability issue that we all have to deal with in the future. How should we sort out the balance between population, climate change, energy systems, food production, health issues and ecological systems in a way that prevents substantial climate change in the future. [29:39]
I just want to mention that there is a role for skeptics, they keep us honest and more correct. In many ways the National Academies were put together in part to address issues in science including those raised by skeptics. Not only our academies, but other academies throughout the world have looked into the scientific issues raised by the skeptics and in most cases the flaws in their arguments have been dealt with, especially in this latest Intergovernmental Panel on Climate Change Assessment Report. It’s healthy for science to have skeptics; however, when you have people like Rush Limbaugh out there, giving over-simplification of the science and outright misinformation, I think that does a great deal of harm. Free speech must prevail, however on scientific issues, we must rely on credible sources. I believe the Bush administration in particular has taken the wait and see approach and it is ignoring scientific advice. I don’t think that’s the way to go. I think we could have been much more aggressive about dealing with climate change and cutting back on carbon dioxide emissions. There aren’t good parallels for climate change. I don’t think that air pollution or water pollution are good parallels in the sense that you can deal with those on a local basis and in a period of a year or so, you know that pollution has decreased.
I believe the connection between climate change and national security will be a growing problem for the world to face. Also, the effects of a failing ecosystem and species loss will be more apparent in the future. Environmental justice is another societal issue. I show slides from a talk that I gave at the American Meteorological Society annual meeting earlier this year. All people are going to be effected by environmental change and climate change, however, the people without power and who are poor will be effected the most. I think that we all have a responsibility to make sure that they’re not overly harmed any more than the other people are. Here I show a figure from the July issue of the AARP magazine where they stressed some strange green fellows… I’m pleased to be in the figure. This is the only time in my life that I’m larger than Arnold Schwarzenegger [audience laughter], but I think it’s going to take all types to sort of deal with this problem. Benjamin Franklin wrote in the Poor Richard’s Almanac "when the well’s dry, we know the worth of water." And I think that we really need to sort of deal with this problem up front.
Finally, clearly both of these gentlemen, Linus Pauling and Al Gore have felt a very strong need to sort of deal with the major problem. In Linus Pauling’s case, of course, it’s the proliferation of nuclear weapons and in Al Gore’s case, getting out the message about climate change. I think that in both of these cases , they’re doing a very noble activity for humanity. I’ll end there, thank you very much. [Applause] [33:28]
Chris Petersen: Any questions for Dr. Washington?
Audience Member: I didn’t see anything in your model about the interaction between the carbon dioxide and the ocean. It seems like as the ocean’s currents change it would change the chemistry that goes on in that interface.
Warren Washington: Yes, the ocean is a very important and integral part of our climate model. I didn’t have time to show here in this presentation the interactions with the ocean. We have a version of our model that does have an active carbon cycle that includes an atmospheric part, an ocean part and a terrestrial part. We include interactive vegetation and circulating ocean biogeochemistry. One of the surprising things that we found was that most of coupled carbon cycle and climate models have found a very strong positive feedback; in other words, as the climate warmed up you enhance the carbon dioxide emissions that go into the atmosphere and therefore having a positive feedback on the warming. One of our young NCAR scientists, Peter Thornton, has found that if you add a nitrogen cycle to the overall system you see a lot less of a feedback. And the problem is that in order for vegetation to grow it needs nitrogen, so that nitrogen cycle is a very strong limiter on how much positive feedback that you get. I’m a big fan of carbon cycle models coupled to climate models, but they’re still in their infancy in terms of our understanding. For example, we don’t know how much carbon dioxide goes into the oceans very well, and how much goes into the soils. There are lots of scientists who are studying that but I would say that we still have fairly large error bars. [35:33]
Audience Member: The question of positive feedback is in the media this idea that a hippie might...
Warren Washington: Right.
Audience Member: ...make up a situation saying that the methane, released from Siberia, or wherever...
Warren Washington: Right.
Audience Member: How do you view those scenarios, with your models.
Warren Washington: On the permafrost? Is that what you’re talking about or...?
Audience Member: Okay, let’s take the permafrost. [36:01]
Warren Washington: Okay, on the permafrost we do see in our models a very strong melting, especially as we go from the mid-century into the end of this century. The thing that we don’t have in our models is a good way to figure out how much of that permafrost melting will lead to methane release. I think that we need to try to improve that part of our model so that we can make sure there’s a feedback that is accurate. Here again, we’re limited by the number of measurements of these sort of processes, because it’s easy for us to model it, but you want to have your submodel based upon a good understanding of the various processes going on so that those are represented accurately in the model. Now I would say permafrost is still a source of uncertainty. [37:06]
Audience Member: How do you feel about expanding your knowledge to include some social science? I’m thinking here of the important role played by governments…
Audience Member: And the role played by corporations…
Warren Washington: Right…
Audience Member: In a sense your models begin after they take action.
Warren Washington: Right.
Audience Member: And you measure something that they have produced. [37:40]
Warren Washington: That’s a very good point and what we’re trying to do at NCAR and other centers is engage the academic community, especially the social scientists and the economists, as full partners. It is difficult because we don’t speak the same languages, but we know that’s the direction we have to go. The shifts in political landscape are the most unpredictable part of it. I like to make the point that if Ralph Nader had not been in the Florida election, we would have had Al Gore as president. We ended up with George Bush whose views on climate change were a world apart from Gore’s. I can only imagine how different the national policy may have been on the issue of climate change would have been if Gore was elected.
Audience Member: [Interjecting] You say it needs more work… [Inaudible]
Warren Washington: I think it needs a lot more work. When you deal with the social sciences, there are a lot of things like psychology of people, and how they get influenced, and how they make decisions and so forth. But it’s a factor that we need to put in our research on climate change. The nice thing about doing it from a modeling standpoint is that we can run different scenarios; we can include a societal factor, or leave this factor out, and we can test it and we can do "what if" experiments, but there’ll always be uncertainty with whatever comes out when you put the social factors in there. [39:22]
Chris Petersen: Last question.
Audience Member: One of your illustrations was… included two Time magazine covers.
Warren Washington: Uh huh…
Audience Member: Since I don’t read Time magazine, I’m left with my 1950’s and 60’s image of Time as being fairly reactionary, conservative. I wonder what is the media position today, say other than the Wall Street Journal editorial page which is notoriously off the charts? Is the media with the concept of global warming or are there hold-outs that say it doesn’t exist, it’s disproven? [39:59]
Warren Washington: Well clearly the Wall Street Journal is on one end of the spectrum. Fox News is another one that is very conservative. I have my favorites like the New York Times. It’s kind of sad to a certain extent because there ought to be a clear separation between the editorial page and the news pages. I feel that journalism hasn’t held up with its responsibility to give unbiased news. For example, if I’m talking to a lecture like here, media says "Well, we want to give balanced news". So they find my old colleague Fred Singer, some of you know, and I know Fred very well going back to many years ago, twenty years, over twenty years ago. And then you have Fred Singer on the podium along with some other scientist who represents over two thousand scientists that were involved in the IPCC, and then he comes out with this rather simple statement, "No I don’t believe that," so forth and so on; the people that are listening to it don’t know that there is one scientist who is very credible and represents a consensus, and somebody who is up to mischief. Fred represents, too often, the oil and gas industry and gets handsome fees for it. And yet he’s not providing objective science. And I think science - especially when it gets into the policy area - needs to be objective. That’s what the policy makers should try to do, use objective information. That’s why we have the National Academy of Science and the other learned bodies that give advice to the policy makers.
Chris Petersen: Thanks Dr. Washington. [Applause] [42:34]
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