|Wednesday, Mar. 7, 2007||House Energy and Commerce Committee: Subcommittee on Energy and Air Quality
Climate Change: Are Greenhouse Gas Emissions from Human Activities Contributing to a Warming of the Planet?
Also: Senate Energy and Natural Resources Hearing on Advanced Energy Technologies & Senate Commerce, Science and Transportation Hearing on National Imperatives in Earth Science Research
10:40: Dr. Hegerl: Warming of the climate system is unequivocal. What caused the 20th century warming? We look for fingerprints of global warming due to greenhouse gases and other external forcings. We came to the conclusion that it is very, very likely that greenhouse gases are responsible for the majority of the warming.
10:45: Dr. Avissar: The climate seems to be increasing in temperature. Is global warming increasing due to human activity? I start having a different opinion. There are still a lot of uncertainties in the models. We have difficulty to estimate what is the proportion of effect of the greenhouse gases.
10:50: Dr. Christy: Yes, the climate is warming, due in unknown part to greenhouse gases.
Energy demand will grow because its benefits are limitless. There are several new initiatives on energy reductions. Kyoto-level reductions will be too small. We will not be able to tell lawmakers we have achieved something with "climate control."
10:55 Boucher: The IPCC found Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic (human) greenhouse gas concentrations." Do you agree?
Oppenheimer, Hurrell, and Hagerl: yes. Avissar and Christy tend to agree, but are not sure.
10:57 Boucher: Avissar testified regional models could be improved by including land use. Do you agree, and why?
Hurell: Global climate models are not perfect, and benefit from land use forcing, regional models are one avenue. I believe that the evidence is very convincing that the range of change goes beyond natural variability. As we begin to make comments on regional variability.
Oppenheimer: I would generally agree with Dr. Avissar. We need to model ice sheets to help us predict sea level rise.
Hegerl: I agree that regional predictions need to take into account land use and precipitation, but do not think that they have much effect on global scale.
Boucher: Let me rephrase the question for Dr. Avissar. Should uncertainty about regional modeling affect conclusions about global modeling?
Avissar: The complexity of the climate system; we use idealized models.
Christy: We've modeled three places and the models have been way off.
11:06: In recess.
12:43: Markey: Why did the IPCC exclude rapid dynamical changes in ice flow?
Oppenheimer: Scientists do not have a model that can accurately reproduce the behavior of the ice over the last few decades, so they do not trust the projections of the models for the next few decades and centuries. So scientists are scrambling.
Markey: Would it be fair to say there's an unknown unknown?
Oppenheimer: I would prefer to refer to call it an known unknown.
Markey: Could the melting of the ice sheets be far worse?
Oppenheimer: Yes, that's certainly true. It could be somewhat less, but not a lot less, but possibly a lot more.
Hurrell: I agree with Dr. Oppenheimer's main point. During the last interglacial Greenland's ice sheet was melted.
Hegerl: The lower limit of sea level rise is much less uncertain.
Christy: This is a very complicated issue.
12:48: Markey: Dr. Christy, you've talked about how life before the Industrial Revolution was nasty, brutish, and short, and criticize people for demonizing energy use by discussing the downsides. If you want to characterize that as demonization, I think you misquote Hobbes. There is a Dickensian quality. It's the best of technologies and the worst of technologies at the same time.
Christy: I didn't see a question there.
Markey: I wanted a comment.
Christy: In my experience in Africa. Energy demand will rise dramatically. I don't see how something short of a global recession or depression will lower CO2 emissions.
12:51 GOPER: I'm a creationist. God is in control. God also calls on us to be good stewards. Mr. Christy's comment about life in a carbon world and the benefits provided by a carbon world is undeniable. Life as middle-class Americans -- maybe I'm not in that class any more. We can't just throw that out of this debate. We hear the term "balance." Capping emissions of carbon dioxide. Whether we can do it or even maintain it. Is there a way of maintaining balance without capping carbon dioxide? Can we emit something up in the atmosphere that would help the balance? Something other destroying our fossil fuel society?
Hurrell: Geoengineering is a topic of discussion that is very early.
Oppenheimer: Ultimately we have to come to grips with the carbon problem.
12:54 GOPER: The hockey stick graph is in the report?
Hegerl: The IPCC report has a section on paleoclimatic temperatures.
GOPER: I was having dinner with a classmate is an astronaut. Our we destroying the atmosphere? Is earth at risk of becoming a rock?
Oppenheimer: That's not very likely.
12:56 Burgess: I'm interested in the discussion about how life is brutal and short without the adequate use of energy.
Christy: The economy would just about be destroyed by 60% reduction in CO2. If just the US, the impact on the climate would be very very tiny.
Burgess: Would we prevent a hurricane, Hurricane Katrina?
Christy: No, Hurricane Katrina was a Cat 3 when it hit the coast.
Burgess: Are we going about this the right way?
I don't sit in your seat.
Burgess: More likely than not: heat waves, increased aridity, increased cyclones. What is the percentage?
Hegerl: Greater than 50%.
Burgess: But in a four person race, the number could be lower.
Hegerl: That's not how this works.
Burgess: I know this is true because I read it on a blog on the internet. We know that solar radiation is the number one source of global warming. The solar contribution is an absolute constant.
Oppenheimer: That's not true. Over the last 30 years we have satellites staring at the sun all the time. The variation has been very very time.
Burgess: That brings me to the blog. Mars has global warming. Are humans at fault for that?
Oppenheimer: Mars also has a greenhouse effect, but we're not responsible.
GOPER2: How many scientists are on the IPCC panel?
Hegerl: Hundreds. Depends on the definition.
Hurrell: There were 152 lead authors and 400 contributing authors to Working Group I.
GOPER2: There was some discussion on the impact of global warming on hurricanes. The lead author of the hurricane section ended up resigning. Are any of you familiar with that?
Hurrell: It was a contributing author.
GOPER2: It seems immersed in total politics. Anything below 3 degrees of warming--developed countries will benefit and developing countries will not benefit. Are you familiar?
Oppenheimer: That's Working Group II. That's an old statement, but it was more likely that developing countries would suffer first.
GOPER2: A submission in Geophysical Review Letters if every nation lived up to Kyoto regulations only 1.26 deg C reduction every fifty years.
Oppenheimer: Kyoto was viewed as a first step. While it's technically correct that Kyoto would only have a limited effect, it would have been a first step.
GOPER2: It would help if we could all be less emotional on this issue. If we can make this less sensation we all benefit. Tell me about DICE.
Oppenheimer: DICE is an economic model that attempts to look at the costs of reducing emissions and the costs of the effects of global warming.
A crude way to look at it: the costs would be several percent of GDP cumulative over 50 years--the costs of the damage would be in balance. A current investment makes sense.
Insley: What would the mean temperatures of the planet be without CO2?
It would be 32 C colder without greenhouse gases like water vapor.
Insley: We're going to be about twice pre-industrial levels unless this Congress pulls its head out of the sand. I'm really glad Dr. Christy came.
Barton: I want it to be clear this 32C change. Most of it is natural.
1:15 Insley: "We're adding carbon dioxide donuts. It's like us eating 5 pounds of donuts each year. Eventually I'll be 400 pounds. It's very concerning." We sort of assume that if we do something about CO2 we'll be living in poverty. I'd like to quote Christian Aid: "It is vulnerable people who are affected first by global warming."
We're going to have to go back to living in the Stone Age. The working assumption is that humans don't have the brains to develop the technology.
Dr. Christy: Americans are innovative.
Insley: What percentage increase of technology do you believe Americans can create as an increase in efficiency?
Christy: I'm a Christian missionary and a climate scientist. I don't think those folks can. I think it would take decades, except for nuclear.
Insley: The argument that it would take decades is not an argument for delay, it's an argument to take action.
Christy: When you say get started, I worry about the people of Alabama.
Insley: If the people of Alabama would adopt some of what people did in California, they'd be better off.
1:20 GOPER3: Mrs. Hegerl, 1300 years ago, what kind of meteorologists were on the planet? What kind of thermometers were on the planet?
Dr. Hegerl: You can reconstruct temperature with proxy data with uncertainty.
GOPER3: Talk about this naturally occuring phenomenon happening with the water.
Hegerl: Water vapor increases have been observed.
GOPER3: I don't know much about science.
Hegerl: We have done relatively well predicting the last 15 years.
GOPER3: Would most of you agree that this is complicated stuff and we should move cautiously?
Oppenheimer: I think the problem should be looked at carefully but the record is thick.
GOPER3: Shouldn't people look at the economic impact?
Oppenheimer: People have. For instance, if the US had implemented Kyoto, the effect would have been about a 1/10th of a percent of GDP per year.
GOPER3: Have you built a climate observational data set from scratch?
Hurrell: I have not. I am a climate diagnostician.
1:25 Walden (OR): Do models accurately model regional climate?
Christy: The answer is no. When the models match the past 100 years, you have to remember that they're plugging in the observed data into the models.
Walden (OR): Does that mean they manipulate the data?
Christy: No, but there is a level of tuning.
Hegerl: The ocean content set came out in 2001. The modelers did not know the data. This is strong evidence in support of the models.
Hurrell: I would like to state for the record that climate models are complicated, but each process are based on the best science. The impressive match is a powerful statement that the models work.
Walden: The upper surface of the ocean cooled significantly. What about that?
Hegerl: Variations over a short time scale are very difficult to interpret, but I would warn against trying to extrapolate from them.
Walden: Do we see short term variation in glaciers?
Oppenheimer: We see dramatic variation in glacier movement.
Walden: It could be 100 years before we get back to equilibrium.
Oppenheimer: It would take about 2 centuries to return to 300 ppm. We're not going to get back to 200 ppm. The likelihood is that we're never going to get back to the preindustrial 280 ppm. We're stuck with some of that CO2 for 1000 years.
1:31 Barton: What's the largest concentration of the CO2 ever in the atmospher?
Oppenheimer: Ever? There were times in the earth's history when there was much more CO2 in the atmosphere than oxygen.
Barton: Isn't it a fact that CO2 was much higher than 300 ppm.
Oppenheimer: That occured very slowly, over millions of years.
Barton: Isn't it true that we're taking 1850 which was in an ice age as the base level.
Oppenheimer: An ice age means 1000 feet of ice reaching across North America.
Barton: Are clouds critical to the warming of earth? Do we understand cloud formation?
Christy: Not well at all.
Barton: I'm told there are about 20 models that portray themselves as being able to model the atmosphere. But they don't model cloud formation well at all.
Christy: From my point of view that would be true.
Barton: As a policy maker, how many millions of jobs should I put at risk for the sake of political correctness?
Oppenheimer: I resent the implication that global warming is a question of political correctness.
Barton: Your testimony is that if we stopped emissions now it would take 100 years for there to be any change.
Oppenheimer: That wasn't my testimony. We could have a substantial change in climate with reductions in greenhouse gases.
Barton: There are some negative forcings. Should we encourage those to combat global warming?
Oppenheimer: If you want people to breathe dirtier air, then sure, go ahead. But I don't think you want to solve one environmental problem with another one.
Hastert: There's not a lot of exactness there....clouds, ice sheets...
Burgess: We've heard a lot of intriguing science. The level of uncertainty we've heard today seems to me that a timeline of July 1 is untenable.
1:39 Hearing is adjourned.