 So there have been a lot of research on climate change that had been done in the 1960s, 1970s, and 80s. And the governments of the world were hearing some fairly dire results coming out of that research. Simple climate models have been run at that time. We're showing that if carbon dioxide was increased in the climate models that the climate would warm up, and there would be a lot of kind of bad things that could happen in the future, that could affect countries in ways where governments would have to make policy decisions to deal with climate change. So in the late 1980s, the government said, hey, we need better information. All this research is going on, we can't really make sense out of it. Why don't we organize and get together and ask the climate science community to provide us the latest information on climate variability and change, so that can inform us on things that we may need to do about it. And so they started working through the UN, through the UNEP actually, United Nations Environment Program, as well as the World Meteorological Organization, to kind of task with doing weather-related things. And they said, why don't we set up some kind of an organization through the UN where we could actually interface with the international climate science community. So they set up the Intergovernmental Panel on Climate Change, the IPCC, a group of governments, not a group of scientists. So at that time, they got together and they said, okay, we're going to form this structure. We'll have an overall chairman of the IPCC who has a very small staff, only two or three people. They organized and contacted all the countries that had science research, climate science research activities. They said, we want to do this assessment. Why don't we get a group of scientists together to come up with this report. And that ended up producing the first assessment report in 1990. Of course, at the time, it was not the first assessment report. We thought that was the IPCC assessment report, not having any idea that it would end up being a regular activity that would continue right up into 2013 and maybe beyond. So the process that we go through, it starts out with what's called a scoping meeting or usually a couple of scoping meetings. These scoping meetings are held with representatives from the various governments and scientists. They get together and the governments say, this is what we want information on with regards to climate variability and climate change. The scientists say, okay, well, this is maybe what we can provide and they then work together to come up with an outline. Then what happens is that scientists are nominated from all the different countries to be possible authors of the report. So each country has its own process of selecting authors to nominate, scientists to nominate. That list of scientists then goes to the international level. There's another committee at the international level that actually forms to lead author teams. They take into account not only area of expertise, obviously, but gender, race, developing country versus developed country and other factors to try to get as well balanced teams as possible that covers all the areas of expertise that has international representation. And so that list of lead authors then comes back to us and we're notified, oh, you've been selected to be a lead author on such and such a chapter. So each scientist that's been selected represents their country and I always like to think of it as kind of a science Olympic. So you're gathering this multinational group of scientists who've been selected to do this activity and you all kind of band together to support each other to do the best possible job, to do the right thing, give the governments the best possible information on the current state of human knowledge on climate variability and climate change. From the very beginning, the IPCC rule has always been that the IPCC assessments are policy relevant but not policy prescriptive. And that means that governments want certain information on certain topics that's relevant for them in their policy deliberations on how to deal with climate change and that's the information that we provide from the published literature on climate science. So we provide the information on climate change to the governments. They decide what to do with that information and that's a very hard boundary in between those two kind of topics. This is something people sometimes confuse. They think the scientists are trying to tell the governments what to do and that's exactly not what happens. That's by rule, that doesn't happen. For political reasons, economic reasons, demographic reasons, all kinds of different reasons, it's very difficult for governments to deal with. So I think if you would have asked me in 1990 when we finished the first assessment report what I would hope would come out of this whole thing, I would hope at that time I would have said, hopefully the governments will realize this is a serious problem and start the wheels in motion to do something about it, even at a very low level. And I think that's something that's been a little bit disappointing that more has happened over the course of these IPCC assessments. But we're still hopeful and we're still doing the best we can do as scientists to give this information to the governments in as much detail as possible so that they have the best possible information to make these decisions. So the workgroup I'm associated with is physical climate science. We don't have any social science considerations by definition. Working Group 2 does have more of that in it because now we're getting into climate impacts, how people respond, how people are affected, and how people adapt. And so there's more social science there. In Working Group 3 on mitigation, the so-called integrated assessment models, they have economic models in them that incorporate human actions and more how people react to climate change and make changes in terms of economics and even demographics and other types of things. What's ended up happening in a number of different countries is individual countries are doing their own assessments aimed specifically at their countries. And the U.S. is no different in that regard. In the U.S., it's actually mandated by law that there has to be a semi-regular assessment of climate change in the U.S. This is going on right now. The national climate assessment is going to be completed, I think either at the end of 2013 or early 2014. So in Boulder, of course, we've just experienced at least a 100-year flood. A 100-year flood, people think, oh, only a hurry for 100 years. It's actually a 100-year flood means that any given year you have a 1% chance of such an extreme event occurring. So this is a rare event. At my house, I got over 16 inches of rain in less than a week. This is unheard of in Boulder. Obviously, I've never seen it in my lifetime. The last time we had a rainfall event like this was 1894. So obviously, nobody alive now has a memory of that event. So when something like this happens, everybody always says, oh, is it climate change? And the answer is, well, strictly speaking, no, because this kind of extreme event was a conjunction of many different factors coming together in a very rare way. It's happened before. It'll happen again. But having said that, we know that we've measured over the last 50 years increases in something we call precipitation intensity. So for a given rainfall event or snowfall event, we're getting more rain or snow out of those storms than we used to get. And those increases in precipitation intensity have gone up on the order of 10% to 20% across the US over the last 50 years. And we understand why this is. That's because the air is warmer. We've measured increases in temperature. We know that warmer air can hold more moisture. So as the moisture is evaporating off the oceans and is carried over land and storms, you have more moisture available to produce ever more intense rain or snow events. So when you have an extreme rainfall event, like we've had in the last week here in Boulder, the extra moisture source from the air that's being held in the warmer air undoubtedly contributed to some of those rainfall totals. How much would be hard to determine. But we know that these events are taking place now in this new Bay State and we know that that's contributing to making these events more severe. So the IPCC brings scientists together from all over the world and in general we all know each other because we all are colleagues. We're all friendly with each other. But scientists are competitive people. Like in any competitive event, athletics, science, anything where there's competition, there's always an edge. You also know that these are the people that are reviewing your papers. When you submit papers, your colleagues, it's an anonymous review but you know that these people you're very friendly with are reviewing your papers and can be quite critical of what you're doing. But in the IPCC, this whole kind of the way you relate to your colleagues changes because now you're in these teams of authors and you're trying to work together in a very supportive, mutually supportive way to produce the best possible assessment that you can come up with. And so when you go to a lead author meeting, these lead author meetings are filled with people saying, oh, how's your chapter going and oh, we're having trouble with this and oh, well maybe we got to get together and decide who's going to cover this topic. And so there's all these cross chapter meetings and say okay, well you're going to do this, we're going to cover that and then within your chapter, your lead authors, a lot of times you're having some fairly contentious debates about how to assess certain literature and things like that. At the end of the day, you're all kind of in it together and you're all trying to work together in a positive way to produce this report. And I've always thought that that's one of the more gratifying parts of being involved in these IPCC assessments and you really bond together and you really form these teams and you're really trying to do the best for your chapter. And I think that's really a great part of the IPCC assessments. Well yeah, so the other part about working with your colleagues in this way is as you're assessing the literature, you can see gaps. You say, well you know, nobody's written a paper on this and somebody should really do something about this. So it actually gives you ideas. It stimulates your thinking and you're thinking, well you know, this is a whole thing that we could really look at in a much better way. And of course anybody that reads the assessment when it comes out would get the same information and can make those same conclusions but as you're putting it together and as you're talking to your colleagues and you say to somebody, hey well have you looked at or you know of anybody that's looked at this, you know, we can't find papers on this, well no, there doesn't seem to be any of this. Well somebody should do that. And part of the real interesting thing scientifically is identifying these gaps because they come up all the time when you're doing an assessment. You can see where there's been missing pieces that are pretty important to try to fill in. I grew up from Eastern Colorado originally and I grew up in a farming background. So I had three uncles who were farmers. My dad was a dryland wheat farmer. We still have our dryland wheat farm out in Eastern Colorado. We rent it out now. But the thing about farming and if you talk to a farmer, they are the ultimate weather weenies and climate. They're so focused on the weather, tomorrow's weather, next week's weather, next season's weather, next year's climate. They really have this perspective on all kinds of different time scales because all of that affects their livelihood. I ended up going into climate science. I actually changed majors a couple of times. But when I got into climate science, I said, well this is something I have an interest in because I grew up with it. And of course the downside of that, I'd go to family gatherings and my uncles would ask me, what's going to happen next month? I said, well, you scientists are always waffling around all the time. You don't know what you're talking about and they'll always be kidding me about the scientists are never giving them hard information. Working at NCAR was really the ideal combination because I was going to the University of Colorado, got a job as a student here at NCAR and could actually see what scientists did. I think that was another important step is that when you think of scientists, think, well what do they do every day? What's research? What's the process? And by working as a student assistant up here, you can actually see how these scientists work and how they function. They helped when I saw that they were using calculus and climate models and I really never liked calculus and I was having to take calculus and I said, oh well I can see why I'm taking calculus because that's what's used in these climate models. That actually made calculus a lot easier for me. And physics was the same way. Physics, I always kind of like physics but then you can see how physics is really applied when physics is all about understanding how things work and mentally visualizing it and then trying to describe that in equation form and so that, watching scientists do that on a daily basis really made going to school a lot easier and taking these hard classes made that easier and it ended up working out that I ended up staying in climate science and still here trying to figure out the climate system.