Climate Instability: Interpretations of Scientific Evidence

I would like to present the speakers. Jerry Shnoor will be talking first and as you can see he has accomplished very much in his career. I won't go through each point by point but he's co-director of the Center for Regional Environmental Research at Iowa city and a member of the National Academy of Engineering and editor in chief of the Environmental Science and Technology, which I believe is the number one journal in the world for environmental science. He has written many publications and has many prizes and awards from other places. Steve Goreham will be the second speaker. He's the director of the Climate Science Coalition of America. He has been working for 30 years in environmental policy and engineering and energy issues. He has his MBA from the University of Chicago and his MS in electrical engineering from Illinois.

He's the author of two books, I won't go through all the titles. Anyway Steve I think you have some book copies outside? And you will be available for book signing after? I won't take any more time. Jerry will you present? -Thanks Billy. It's a pleasure to be here. Can you hear me? Nope? How about this one? Is that better? Okay. It's a pleasure to be here. I've worked with many people from the CEEE at University of Northern Iowa, including Bill Stigliani, for many years. We worked together when he was at the National Research Council, when he was in IIASA, that's the International Institute for Applied Systems Analysis in Laxenburg, Austria. Now ever since then in my role at the Center for Global and Regional Environmental Research at Iowa and his role here in CEEE. It's a great pleasure to be here and to talk about one of my favorite things, climate, and to try to tell you what I know about what I've learned about the science of climate change.

I'm not a climatologist. I apologize for that. I am an engineer. I'm a chemical engineer and an environmental engineer. I work closely with climatologists to run models of the effects on streams and soilds and agriculture as a result of land use and climate change. I'll try to tell you a little bit about what I've learned and why I've come to believe that climate change is a very serious problem. It is caused by humans and it's something that we should take seriously and begin to act upon. I went to Iowa State University in chemical engineering. When I graduated if you were to tell me that we could change the entire planet earth, this big blue marble that we're talking about today, I would have been a little skeptical I think. Maybe the atmosphere. If you look here it's a really thin veneer. The mass isn't actually so great. Maybe the atmosphere, the top 100 kilometers or so because we're 7.2 billion people with a gross world product that's increasing, doubling, every few decades.

Yeah maybe we could change the atmosphere. Never would I have thought that we could possibly change the oceans. It's such a great thermal mass but I'm gonna show you data which indicates that indeed we are able to do that. The thing about climate change is that it's not any one series of data or measurements. Rather it's a story. It's a story that it becomes quite compelling when you consider the multiple lines of evidence. Just in this talk today alone I will be using things from surface temperature, down borehole records, ocean temperature, PH, CO2 and so on and so on. It's all of this massive amount of information that's coming from so many domains. It's not a perfect story. There's uncertainties to be sure and I'll try to point out where some of those uncertainties are. Taken as a whole, from all these sets of data, all these lines of evidence, it's a very clear and compelling story that humans are the base of the temperature, the changes that we're seeing in climate today and I'll show you why I think so.

Of course the bases that we've been arguing, I've been taking students since 1992 to the big international meetings like the Rio Earth Summit in 1992. I've seen about 190 countries arguing for over 20 years tooth and nail about how to turn this curve upside down. For 20 years we've been arguing about this and making very very little progress. It should at first give us some pause that we're unable to even make this come to a peak, let alone what it looks like we need to do, and that is a steep reduction off of this graph, maybe an 80% reduction in the next few decades. When you emit that many greenhouse gases, when you burn fossil fuel that's been stored in the earth's crust for 340 million years since the carboniferous period, that's when the goal was first laid down, and you mine that and you burn it and you put it back into the atmosphere in maybe 2 or 300 hundred years, that's just the blink of an eye in geologic time, of course you're gonna change the atmosphere. It's a no brainer. When you take something that's been stored for 300 million years and re-release it into the atmosphere in 300 years, of course you're gonna change the atmosphere, and indeed we are.

If you went to the doctor and this were your blood gases, I submit that you'd be a little bit concerned. This is our carbon dioxide in the atmosphere and we should be a little bit concerned. We know for sure that that carbon dioxide is coming from humans. There's no debate about that. For one thing, it began in about the Industrial Revolution when we really began to burn coal in earnest with the invention of the steam engine in the late 1700s, early 1800s. It started to increase. A, the timing is right. B, the amount that's increasing each year, now about three parts per million each and every year, can be fully accounted for by our measured emissions. Both measured from satellite data and measured from reporting areas. A, the timing is right. B, the amount is right. We can fully account for the accumulation of carbon dioxide in the atmosphere based on how much we're emitting.

It's about half of what we're emitting. See the dynamics are right. We can look at the isotopic ratios. We know it's coming from the fossil fuels, some of which are as old as 300 million years old. And we can see it mixing from the northern hemisphere where most of the industrialized countries are, to the southern hemisphere. The dynamics are right. Therefore the carbon budget is out of sync. There's a lot of carbon moving around to be sure. Roughly maybe nine is due to humans, both deforestation and direct emissions. About three of that nine we think on net are accumulating in the terrestrial environment, a grading, for us, that's pretty uncertain. We really don't have a good handle on that globally. We have a better handle on this number. About two of that nine seem to be accumulating in the oceans and changing the ocean chemistry. More about that in a moment. The remainder is about four that's accumulating in the atmosphere. When I first came to the University of Iowa some years ago I had a slide similar to this it was at about 725 billion metric tons of carbon dioxide in the atmosphere.

Now it's about 800. Clearly we're accumulating more and more carbon dioxide in the atmosphere. You might say it's 400 parts per million, that's a trace gas right? It is. It's a trace gas in the atmosphere. But why it makes a difference, the so what, the philistine question is it's a radiatively important trace gas. Even at trace levels it makes a difference in the earth's energy budget. I'll show you. One of the reasons that CO2, even though it's a trace gas, and other greenhouse gases matter is because they absorb at certain bandwidths, certain wavelengths here, here, here, and along in these smaller ones. It's absorbing infrared radiation. That's the heat from the earth that's coming off of the earth so in the atmosphere as we build off these greenhouse gases it's like putting a blanket over the earth or rolling up the windows of your car in the summer time.

It absorbs that back radiation and causes anything with more than two atoms per molecule is capable of this because it can begin to vibrate. CO2 as you shine infrared radiation on it it begins to vibrate. That captures the radiation and causes heat to build up. That's exactly what's happening. Also ozone can be important, although it's not a long term trace gas. And water vapor is very important. More on that later. As best as we can tell from measurements and models, the earth's energy balance is out of whack by about one watt per square meter. That may not sound like much because 340 or 342 are coming in from solar radiation and according to this 339 are going out. About one watter per square meter. It may not sound like much but it's enough to begin to warm the earth and cause some pretty significant changes like melting ice. The result of that out of whack energy budget is the increase in temperature on average over the whole planet.

This isn't really what bothers me, the 0.8 degrees celsius or 1.4 degrees fahrenheit increase in temperature overall. It's really the variance in that, the extremes, that are more troubling. For areas like the arctic it's really quite a lot, maybe two or three degrees celsius already causing that. We think we understand that. It's a positive feedback loop in the parlance of climate change, in that as the earth first begins to warm the arctic ice, which is floating, starts to melt. That white reflective surface yields to a dark sea. The dark sea warms more, melting more ice, which causes the albedo to decrease even more and it's just a positive feedback loop. That's why the arctic is so much warmer than the average here in Iowa of maybe 0.8 degrees celsius. The clearest signal to the climatologists is this temperature signal in the last 30 some years, since 1980.

The 1980s were warmer than recent history. The 1990s were warmer than that. The 2000s were warmer than that. We've had a series of monotonic increase in the global average temperature in recent decades. I tell my students that you can think of climate change is the long term manifestation of our energy balance. Weather is what we talk about today that it's raining today. Climatologists talk about decade as maybe the single data point. They're interested in decades to centuries to millennia to hundreds of thousands of years and that's what we're talking about today. We really have about three good data points. 80s were warmer than before, the 90s were warmer than that, and the 2000s were warmer than that. There's some interesting controversy over this sort of pause which we've seen in the 2000s. It's shown here it's still the warmest decade on record but we think that's due to an increase in heat in the oceans that has been transferred, which I'll show you in a little bit. We know that the carbon is coming from us and we know that it's a radiatively important trace gas and we know that it is beginning to warm the earth.

Here's how we know it. First, if you shine infrared radiation onto greenhouse gases it will get warmer. That's a fact. At one point it was called the kinetic theory of gases but that theory has been proven so many times. If you shine that infrared radiation 100 times on the same bag of greenhouse gases you'll get the same reseult 100 times. It's a fact that these are radiatively important trace gases. We have satellite measurements of the outgoing long wave radiation from the top of the atmosphere. We can see that we're missing the spectrum in exactly the wavelengths that I showed you earlier where it's being absorbed by the greenhouse gases. We're missing those wavelengths. What's more, we can see since 1970 a decrease in the total energy going out. That's consistent with the fact that you've laid a blanket over the earth and you're beginning to keep that heat in.

Furthermore, we have surface measurements also of the spectra and the amount of radiation coming back down from the absorbed long wave radiation in the atmosphere. All of these make up the story. This multiple lines of evidence. The compelling story that's consistent with first the atmosphere warms and it's a top down warming from there. The result is the changes in this energy result in increasing temperatures. It's not one study. The way science works is you have a hypothesis. That hypothesis, at the same time you have an alternative hypothesis of what could be causing the same phenomenon. You begin to do experiments and you reject the alternate hypothesis and finally the remaining hypothesis is a proven theory. It's a theory that everybody accepts like the law of gravitation, that the apple will fall from the tree each and every time that it's released by it's stem it'll fall down. That's what's happened here. We had the original measurements in 2001.

Followed up by all of these peer reviewed published measurements. They don't agree 100%. There's uncertainty in the values. But taken as a whole the multiple lines of evidence very very compelling. When you try to calculate how much radiation could be trapped by these greenhouse gases this is the latest assessment in the IPCC. It was released in September of 2013 by hundreds of scientists around the world working on there. It's pretty hard to get my colleagues to agree on anything, I must tell you. To get hundreds of scientists to sign off on these reports is actually very very difficult. This is the consensus. You also can see there's big uncertainty in how much methane is doing, how much black carbon is going in the atmosphere. The error bars can be large. Yes there's uncertainty in the estimates, but that uncertainty again leads to a conclusion that, summed up, some things are causing negative effects on our energy balance, some things are causing positive effects on our energy balance.

In net, we've got maybe one watt per square meter increase so far. We're just at the beginning of this thing. We're very early in the story. Remember, only three data points so far. It just will continue if we don't begin to curb our emissions. Oftentimes to audiences I don't even show anything about the models. So far I've only shown you data, and the data is compelling enough. But I should also mention that another line of evidence is the models. We take everything. First we make a back of the envelope calculation. When things get too complicated for that you make a spreadsheet. When the spreadsheet will no longer do you take everything you know about momentum, heat, and mass transfer, you put it into a computer model.

That's the only thing we can do is to take the best estimates of what we know and make a calculation and we do it with computer models. When we run the models here's the rough observations. When you run the models with just volcanoes, sunspot activity, changes in the sunspot, changes in the earth's elliptical orientation, you get this. When you add the greenhouse gases, the human effects, with model results you can match the data pretty well. Without the greenhouse gases you can't reproduce what's happened in the past. Solar cycles won't explain it, despite what you might have heard. The solar cycles we get about 0.1 – 0.2% change in the sun's energy and we call it a solar constant but it's not. It changes. You can see with the 11 year cycles it's changing here. And it hasn't changed much since the 80s, 90s, 2000s, which I've shown you where the temperatures are going up decade by decade by decade.

If you want to go more into the solar cycles we can do that but solar correlations with global temperatures simply don't work. With high confidence, then, temperatures are increasing due to human activities. We know this because the warming can be explained by the radiative effect of these gases that we're adding. We know it because we've measures both the outgoing long wave radiation by satellites. It's consistent with a warming due to the build up of greenhouse gases. That's satellite data. We've got sensors on the earth which are measuring the long wave incoming radiation, which is increasing because of this blanket that's beginning to warm the earth. And the oceans are warming. It can't be explained by any transient phenomena or even ocean circulation. It's very clearly a top down warming that can only be consistent with a story that first we've added the greenhouse gases, they've begun to warm the atmosphere, and then those in turn have begin to warm the oceans.

We can see the signal in the north Atlantic 700 meters down, a diffusive signal of warming from the sea surface all the way down. A very consistent global climate change story. I think it's lost on people that we have a pretty good measurement of how much we're warming. Since 2005 3,000 argo sans, or buoys, were launched. You can go online right now and see where they're all floating, these 3,000 sans. They're giving us a really good picture of all the energy coming in and all the energy going out. If more is coming in than is going out, you can be sure that you're warming. And it's a top down warming. They're solar powered. They dive down 2,000 meters and the entire ocean is warming as a result of this climate change. It's a lot of warmth actually. We said that 0.

8 degrees fahrenheit in the atmosphere maybe doesn't sound like very much but when you sum it up for the whole oceans it's about 20 times the primary energy consumption of the entire planet. 20 times. It's quite a legacy that we're leaving for future generations. Here's the sea surface temperatures from NOAA. Just in my lifetime, the last 50 years, sea surface temperatures have increased when you smear this over the whole planet about one degree fahrenheit roughly. Remember 1.4 degrees fahrenheit in the atmosphere, one degree fahrenheit in sea surface temperature. Top down phenomena first caused by the addition of greenhouse gases. What's more, remember I said you would have never convinced me that we could change the oceans in my lifetime. It's not just the radiative effect of these greenhouse gases, it's the sheer chemical effect. We're massively out of balance on the oxidation reduction reactions in the atmosphere because when you take something that's been stored for 300 million years and you use oxygen from the atmosphere to combust i right now you're gonna have an excess of oxidating products.

Those oxidation products include carbon dioxide. That carbon dioxide is a weak acid. The weak acid is exchanging with the ocean and beginning to acidify the ocean. In my lifetime the PH of the ocean has changed from about 8.2 to 8.08. That may not sound like much but it's about a 30% increase in acidity just in the last 50 years. That's an amazing change, both in the chemistry and the thermal mass and quite a legacy we're leaving for future generations. This shows also the increase in CO2, the decrease in PH, consistent with Henry's law, and the gas exchange at the surface where PCO2 is increasing as a result of the carbon dioxide in the atmosphere. There's other effects that we haven't talked about but I'll go through quickly. Those include very heavy precipitation events. We have satellite data that shows very clearly an increase in high clouds. We have infrared instruments on the air on the aquasatellite. These infrared instruments can see the increase in humidity.

You may have noticed it. Our nights are warmer due to more moisture in the air. It makes sense because as you begin to warm the earth it's a warmer atmosphere, it can hold more water, there's more evaporation from the oceans. More evaporation means more moisture in the air. We see it very clearly with the satellite data. More moisture in the air means more high clouds. More high clouds means more intense precipitation events. Again a very consistent and compelling story overall. In the midwest about a 45%. You experience it here in Waterloo on Monday night. If you look back in the record at Waterloo Cedar Falls, it's about a 100 year record, you're very hardpressed to find a day when you had four inches of rain in a single day.

I've done it. If you look now it's really not uncommon to have a four inch rainfall here. That's the kind of change you see. This is the clearest thing in your instrumental record is the increase in very heavy precipitation events and it's completely consistent with the climate change story. In Iowa we've seen increase in very heavy precipitation. .