Friday, September 29, 2006

When the history of climate change is written ...

I'm quite convinced that the citizens of the Earth will at some point band together and attempt to stabilize atmospheric CO2 abundances . If I were a betting man (and I am), I would bet that an international agreement will be reached during he first term of the next U.S. President (2009-2013). Let's hope it's sensible and successful.

When the history of AGW is written, I believe that three occurrences will have been crucial in setting the stage for CO2 emissions reductions:
  • Hurrican Katrina - we can argue about the effect of AGW on hurricanes, but there's no question in my mind that Katrina had an affect on how many view AGW
  • Drowning polar bears - images play a key role in policy debates, and images of so-called charismatic megafauna can quickly become iconic. These images appeal to the obligation many feel for stewardship of the planet.
  • Al Gore - Love him or hate him, his movie has had a huge effect on the debate --- not on the hard-core Gore haters, nor on the AGW believers, but on the undecided middle of the debate. And not necessarily because they went to see his movie, but because his movie has kept AGW in the news and on the public's radar.
Together, these three events have been crucial in generating the growing wave of awareness on the issue. In fact, I think we've recently passed a tipping point, where the question has changed from whether to take action to what form that action will take.

Wednesday, September 27, 2006

Has the climate warmed since 1998?


1998 was a blistering hot year, caused primarily by an enormous El Nino that year. 2005 was hot, too, and while some claim it was hotter than '98, my view is that it was a statistical tie.

Does this mean that global warming stopped in '98? (as argued in places like this) The answer is no. To illustrate, let's consider some synthetic data I made up.

First, let's assume that the human contribution to globally averaged temperatures looks like this:

This is 0.2 deg C per decade, similar to measurements over the past few decades. But as we all know, other things also affect our climate. A particularly good example is El Nino. During an El Nino, the globe warms considerably compared to non-El Nino years. El Nino's occur every few years, so let's assume that El Nino's contribution to global temperature looks like this:

Now let's sum them.

As one can see, the El Nino signal in our little example (and in reality) totally dominates the human-induced signal.

So if one wants to know how much "global warming" has occurred since 1998, one has to subtract out the influence of El Nino. If one does that, then 2005 is much hotter than 1998, and global warming is alive and well.

The important lesson to learn here is one of time scales. Looking at the temperatures from 1998 to 2005 means you have about 8 years of data. This is comparable to the El Nino cycle time. If one looked at much longer times (e.g., a few hundred years), the effect of El Nino would be less important and more obvious. To illustrate that, here's the same two time series extended out 200 years.
As you can see, the upward 0.2 deg per decade signal is quite obvious in this plot.

The same is true if the time series is much shorter than the time scale of the variation. That's why we don't have to worry about ice age/interglacial variations in our analysis of the warming of this century. But by picking a time scale that is comparable, it maximizes the confounding effects on any trend calculation.

People who argue that global warming stopped in 1998 are 1) clever advocates who are willing to mislead to win the argument or 2) don't understand much about the climate system.

Tuesday, September 26, 2006

Good new FAQ on global warming

My colleague Steve Sherwood has a good FAQ on global warming here. It's another resource you can show your Aunt Petunia ... you know, the one that still doesn't believe that atmospheric CO2 is increasing!

Monday, September 25, 2006

Still more Bush on global warming

Following on my series of blogs on Bush, SciGuy had a link to this video. A little comedy to lighten your day!

Sunday, September 24, 2006

Are scientists biased?

One of the parts of the Wegman report that I objected to was his characterization that scientists are biased towards getting results that confirm the underlying paradigm of AGW:
there is a tightly knit group of individuals who passionately believe in their thesis. However, our perception is that this group has a self-reinforcing feedback mechanism and, moreover, the work has been sufficiently politicized that they can hardly reassess their public positions without losing credibility.
What this idea overlooks is that one gets ahead in science not by agreeing with previous work, but by advancing new ideas. The bigger the new idea, and the bigger the old idea that it replaces, the more fame and success accrue to the scientist. Look at famous scientists through history and you won't find a single one that got there by agreeing with the prevailing wisdom.

If you're a member of the so-called "hockey team," you're not going to get much credit or respect from the community if all you do is agree with hockey stick. Rather, an individual scientist will do much, much better if he can show that his competitors' (aka colleagues) work is faulty or biased. And that same individual scientist will do much worse if his or her work is viewed as faulty or biased. This incentive to destroy previous work explains why, in any group of a few scientists, there will be at least two that hate each other.

Scientists are human and all of us have personal biases. But because scientists know that important ideas they advance will be re-tested by other scientists, there is a strong incentive to be careful and conservative in their claims.

People that argue that there's some type of "conspiracy" among climate scientists to increase funding by producing "alarmist" science are either a) a clever advocates trying to obstruct AGW policy by attacking the science or b) someone who doesn't understand science.

Thursday, September 21, 2006

My thoughts on the hockey stick

A few people have asked me what I think about the hockey-stick debate. Here are a few thoughts.

(1) I never say whether the hockey stick is "right" or "wrong". Labels like that are ambiguous and misleading. I actually don't know whether it was wrong or not, but I do know that some of the best research has turned out, in the end, to be wrong; it's value was in pointing the community towards an interesting question.

(2) I adopt the NRC's party line that we simply cannot say whether the MWP was warmer or not than the present. I've seen a lot of people misinterpret this to mean that we can now say that the MWP was warmer than present. That's incorrect --- the uncertainty cuts both ways. We cannot say today is warmer than the MWP or that the MWP is warmer than today. We just do not know.

(3) The hockey stick plays little or no role in attribution of the recent rise in temperatures to human activities. For example, see this blog entry where I talk about why we think much of today's warming is caused by man. Note the absence of any reference to the hockey stick. Thus, the statement that humans are contributing to the present day warming remains unscathed.

(4) The scientific community should provide code and data to any interested party. Not being forthcoming with these things seems to me to violate the ethos of science, well summed up by the AGU's motto: "unselfish cooperation in research." And it makes us look bad.

Wednesday, September 20, 2006

Speech by Boehlert

(thanks to a tip from a reader)

I'm really going to miss Sherwood Boehlert, who's retiring at the end of the term. Here's why:

September 20, 2006
Science Committee Press Office: 202-225-4275
Joe Pouliot,
Zachary Kurz,


WASHINGTON - House Science Committee Chairman Sherwood Boehlert (R-NY) today delivered the following speech at the Climate Institute's Washington Summit on Climate Stabilization:

I know that yesterday you heard from some of the world's leading scientists about the frightening possibility that the earth's climate may change more quickly and abruptly than expected, and whether there's anything that can be done to avoid that.

Well, this morning's session should offer a break from all of that. Instead, I'm going to talk about the frightening possibility that Washington's political climate may not change more quickly and abruptly than expected, and whether there's anything that can be done to avoid that.

Certainly, without abrupt political climate change, it's going to be next to impossible to do anything about global climate change.

Let me hasten to add that by calling for "political climate change," I'm not covertly advocating a change in political party control. There are segments of both parties that support action to address climate change, and segments in both parties that don't.

But right now, those of us who seek action are confronted by ideology, by fear, by a reluctance to lead, by apathy, by comfort with the status quo. All of that has to change, and I think it is beginning to change.

But before I get to some of the better news, let me give you one illustration of how hard it is to make progress right now. One of the simplest steps we could take to reduce greenhouse gas emissions would be to increase the mileage of our auto and light truck fleet.

It just so happens that increasing mileage would also enhance our national security, bolster our economy, and save consumers money.

And, according to the National Academy of Sciences, we could increase mileage substantially, using technology that already exists, without any reduction in safety. So to exaggerate only a little, this should be a no-brainer - even without taking climate into account, but especially when climate concerns are added to the mix.
So has Congress voted to increase mileage requirements, known as Corporate Average Fuel Economy, or CAFE standards? No.

The proposal has been defeated repeatedly in both the House and the Senate by a mixture of conservative ideologues, and Republicans and Democrats who are lobbied by automakers and/or the United Auto Workers. And I should know because I'm the guy who offers the amendment in the House each time.

Now in the House at least, we do a little better each time. We got 160 votes in favor in 2001, 162 in 2003, and 177 in 2005, and we know we would do better still this year because Members have declared publicly that they've changed their position.

Unfortunately, we can't seem to get a vote scheduled this year, despite high gasoline prices, perhaps because we're on the cusp of victory, at least in the House.
But my point is a more sober one: if we can't make a relatively simple change in mileage regulations - a change to an existing regulation that doesn't even require new technology and that would have numerous benefits aside from the climate implications, then what does that say about our ability to reduce greenhouse gas emissions? It certainly doesn't say anything good.

So all of us who want to see some action on climate change have our work cut out for us.

In the House, many, perhaps even most Members, still question whether climate change is a genuine phenomenon. The scientific consensus has simply not pierced through the ideological barriers. And there are briefings almost weekly sponsored by groups that argue that climate change science is some kind of environmental conspiracy, and they bring seemingly credentialed people forward to make their claims.

We've even had to confront the situation where Members of Congress have tried to investigate scientists whose views made them uncomfortable.

In July 2005, the Energy and Commerce Committee initiated an investigation of Michael Mann and his colleagues who wrote the so-called "hockey stick" article. I took that Committee to task, arguing that raising questions about scientific methods and conclusions was fine, but intimidating scientists was not.

As I wrote to that Committee, "The only conceivable explanation for the investigation is to attempt to intimidate a prominent scientist and to have Congress put its thumbs on the scales of a scientific debate. This is at best foolhardy; when it comes to scientific debates, Congress is 'all thumbs.'"

Eventually, I asked the National Academy of Sciences to convene a panel to look at the historic temperature record. That panel came up with what I think just about everyone views as a balanced and thoughtful report.

It took issue with some of Dr. Mann's initial methods and specific conclusions, but it confirmed that the past few decades have been hotter than any time in at least the last 400 years and probably longer.

This July, the Energy and Commerce Committee had a hearing on that report, which was a legitimate Congressional step to take.

We'll have to wait and see how the testimony at that hearing will influence the future thinking of the Members of that Committee.

I should say that the White House position has been far more nuanced than that of most House Members. The President has stayed within the bounds laid out in the 2001 National Academy of Sciences report on climate change that he requested.

The emphasis of the White House view changes a little depending on who is speaking, but the White House has not been in the camp of those who deny climate change, although it has shied away from mandatory action to combat climate change - unfortunately, in my view.

Now, we're seeing rumors in the media that the White House may be planning a major climate announcement in the next few weeks. I have no idea if that is true.
I'm more concerned about how the Administration is implementing its existing climate plans and programs. Our Science Committee's Energy Subcommittee has a hearing later today, for example, on the Administration's strategic plan for the Climate Change Technology Program, or CCTP.

I have the highest regard for Energy Secretary Bodman, an alumnus of Cornell and MIT, who is a true advocate for science and a candid and creative thinker. But I am not a big fan of the strategic plan, which is more of an inventory of existing programs and a wish list of possible future ones, than a planning document with clear priorities.
Moreover, as is often the case with this Administration, the plan is silent on what policies might be necessary to actually get new or improved technologies into the marketplace.

"If someone builds it, they will come" is not much of a technology deployment strategy, especially when the immediate and significant benefits of new technologies may accrue more to the public as a whole than to the individual consumer.

The example of hydrogen illustrates my point. Hydrogen has a long, long way to go to be a useful energy source, but its potential is enormous and worth pursuing. But we're not going to be driven to a hydrogen economy simply through market forces.
Every transportation revolution in American history - canals, railroads, turnpikes, air travel, interstate highways - has been underwritten by the government.

It's folly to think that that wouldn't be true of a hydrogen revolution, especially since a hydrogen "revolution" would require displacing our current infrastructure, an infrastructure that works just fine from an individual perspective.

But the good news is that the Administration understands that we need new technologies to address climate change, and that the government has a role in developing them.

The third federal player is the Senate, and Senator Bingaman can focus on them. But the Senate, thought it pains me to say it, has been the leader on climate change policy, albeit with minimal results.

Legislation that is explicitly designed to address climate change has at least come up for a vote in the Senate - something that is almost inconceivable in the House. And bills like the McCain-Lieberman cap-and-trade proposal have done respectably, although they have not been passed.

One of the most hopeful events in Washington related to climate change all year was the all-day session that Senator Domenici and Senator Bingaman held back in April to have serious discussions about how greenhouse gas emissions might be regulated.
At that session, not only the senators, but also key business leaders, expressed openness to finding ways to control emissions.

And an even more hopeful sign is what's been happening in the states. California and the northeastern states are trying to take concrete action to reduce greenhouse gas emissions. And many other states and localities have expressed interest in reducing their emissions.

Given the way states compete for jobs and the fact that the impacts of greenhouse gases are felt internationally, not locally, this state interest is not what one would expect. But it's a sign that the public is beginning to sense that this is a problem that must be addressed.

And, of course, the key to creating abrupt political change will be to further engage, educate and inspire the public. Politicians are responsive to public opinion, even in this day and age of political manipulation and multinational corporations.

In fact, in this era of the Internet and constant polling, politicians may be, if anything, too responsive to momentary shifts in public opinion.

So what's needed is for scientists and politicians and concerned business leaders to redouble our efforts to reach out to the public through as many different forums as possible. Complacent satisfaction with our own right beliefs won't carry the day.

The abolitionist Wendell Phillips famously said, "One man on the side of God is a majority." But while that no doubt got Phillips through some lonely times, the anti-slavery advocates didn't gain political influence until they won more converts.

So scientists have to engage. And what scientists say needs to be clear and accurate and modulated and persuasive. Hyperbolic claims will only diminish scientific credibility over time.

Scientists have to be clear about what we know, and about what we don't. They need to be "up front" about uncertainties - and about the potential costs of waiting until all uncertainties are resolved.

(I always quote former Governor Tom Kean's line about acid rain. He said that if all we do is continue to study acid rain, "we'll have the best documented environmental disaster in history.")

We need to lay out an argument for action, but we won't win by mimicking the opposition's tendencies toward rhetorical excess.

And we need to keep in mind that if we win - if the political environment changes so that a desire for action takes root - then our hardest tasks will be ahead of us.

We may end up longing for the days of debate over whether climate change is real - because the intellectual and political decisions we will have to make to confront climate change - whether through mitigation or adaptation or, more likely, both - are going to make today's debates seem like child's play.

I don't think there's anything about the European experience post-Kyoto, for example, that should make us think that this is going to be easy.

So, like abrupt climate change, abrupt political change will present us with a different and problematic world with new and uncomfortable choices. But unlike abrupt climate change, a changed Washington should give us reason for hope, despite all its attendant difficulties.

Climate change discussions can be consumed by gloom. They can remind me of the opening of Woody Allen's classic essay, "My Address to the Graduates." It starts: "Today, we are at a crossroad. One road leads to hopelessness and despair; the other to total extinction. Let us pray we choose wisely."

I think our choices are a little better than that, and if they're not, we'll never win over the wider public.

We have had successes in the recent past in winning over skeptics and taking action. We have controlled the CFCs that created the ozone hole. The Bush Administration has imposed strict new regulations to control fine particles - the health effects of which were still the subject of angry debate not so long ago.

These problems were easier to tackle than climate change, but they didn't seem very easy at the time. The public and policy makers had to be convinced of the science so that difficult concrete steps could be taken.

So I look forward to working with all of you, to continuing to learn with all of you, so that we can create a political climate in which action is possible on climate change.

That's going to take a lot of tough and honest discussion. But it can be done. If we break through the current apathy and cynicism, we can revive American politics, and our environment will be the beneficiary.

Thank you.

What is the Earth's ideal climate?

In another thread, a commenter asked an interesting question: what is the Earth's ideal temperature? This question is often used as a version of the "AGW might be good argument": the point was that perhaps the ideal temperature was warmer than today's, so climate change might actually be beneficial.

Given everything else equal, one might be able to make an argument that a warmer world might be better. However, everything else is NOT equal. Rather, we have adapted to our present climate and made significant investments in these adaptations. We build cities in places where it makes sense to put them (with the notable exception of New Orleans), we build infrastructure where it makes sense to put infrastructure, we perform economic activity where such activity makes sense. If the climate changes significantly, it might take enormous investments to adapt to our new climate. Our previous investments in infrastructure might become worthless.

Consider this example. You build a sawmill next to a roaring river, using the river as a power source for the mill. Now AGW causes the precipitation pattern to change and the river moves miles away. In this new world, the river might have higher flow rates, which would provide MORE energy to the mill, which would be a good thing --- if the mill were still on the river. But the mill is no longer anywhere near the river. So you have to build a new mill on the banks of the new river. This investment in new infrastructure is potentially expensive, and some countries will not be able to afford it.

My point here is that any question about suitability of future climates has to take into account our investment and adaptation to our present climate.

Monday, September 18, 2006

More on Bush climate u-turn

I received an e-mail from a distinguished scientist (member of the Academy) saying:
A few months ago I heard from a friend that Karl Rove had met privately with a small group of global warming luminaries that included Bob Corell, and that Rove was listening intently and sympathetically to what they were saying. The article at this link predicts that something big is about to happen, perhaps at Rove's direction. Bizarre as it sounds, I'm inclined to believe it.
I blogged on this recently here. I don't normally put too much faith in hearsay, but I also believe there's a grain of truth here. My current theory is that this is a "trial balloon" put out by the administration to see how much screaming and howling there is.

Overall, however, this is not necessarily inconsistent with an evolution in Bush's rhetoric over the past few years. In 2001, he emphasized the uncertainties in our science. As that position moved from shaky to downright untenable, however, his rhetoric shifted to fairness (China hasn't signed on, etc.) and economic (we'll put people out of work). He really doesn't argue the science anymore.

Stay tuned for more!

Thursday, September 14, 2006

Important news

An interesting news report is circulating around the blogosphere today. Allegedly, the Bush administration is going to propose we limit CO2 to 450 ppmv by the year 2106.

If true, this as an incredibly important event --- it will move the debate from "should we take action?" to "what action should we take?" In other words, the debate will evolve into a discussion of what the target should be --- and this is (in my opinion) exactly what we should be talking about.

The long lifetime of CO2 in the atmosphere means that we cannot wait for 50 years to start reducing emissions if we want to hit 450 ppmv. In fact, we need to start deviating from our baseline in the next 10 years or so in order to avoid having to make large and disruptive cuts later. And the near-term actions required are pretty much the same for a wide range CO2 targets and timelines. Thus, while some will critize the target date of 2106, it will be one or several decades before actions in pursuit of this target preclude more ambitious targets.

ps: I've turned on "comment moderation" on the blog as a test, so your comments might take a few hours to appear. Your patience is appreciated.

[Note added later: The more I think of this alleged proposal, the more puzzled I am about it. The target (450 ppmv) and the time period (2106) are not really consistent. It is almost certainly the case that in order to stabilize CO2 at 450 ppmv at the beginning of the 22nd century, one has to be close to or at that target in the middle of the 21st century. So why put the target date 50 years later? Perhaps this is a cynical election year ploy, as suggested by several commenters. Or maybe there's something I'm not considering. Any thoughts on this are welcome.]

Wednesday, September 13, 2006

Tuesday, September 12, 2006

How do you define success?

Some people define it in terms of Nobel Prizes or election to the National Academy. But I define success as being interviewed by The Houston Chronicle's SciGuy, Eric Berger.

At any rate, I've made it!!! You can check out the interview here and listen to a recording of the entire interview here.

Sunday, September 10, 2006

Editorial in the Economist

Check out this excellent editorial in the Economist. I have a few nits here and there with it, but overall it is what I would have written if I were a much better writer. I think it makes the essential points with great precision.

Friday, September 08, 2006

Three caveats

Not everyone appreciates the carefully caveated statement in the IPCC's TAR about the attribution to humans of the current warming. Let's take a closer look at the exact statement:
In the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations.
There are three important caveats in this statement, which are often ignored by strawman-toting advocates.
  1. "most of the observed warming": this says that humans contributed > 50% of the warming, but it leaves the door open for a significant amount to be due to non-human influences.
  2. "last 50 years": this says that we can identify the hand of humans in only the recent warming; before that, the data are too poor to unambiguously assign the cause of the warming.
  3. "likely": in the carefully nuanced language of the IPCC, "likely" denotes a confidence of about 75%. Thus, there is a possibility that this statement is wrong. This reflects the fact that our knowledge of the climate is imperfect, and it is possible though unlikely that new research could significantly revise our understanding of the climate system.
The main problem is that when advocates use the IPCC in their policy arguments, the carefully crafted language is abandoned for much stronger statements that support the advocates position. When these positions turn out to be false, the blame falls (unfairly) on the IPCC. Clearly, I think we all need to read the IPCC with the scientific precision with which it was written.

Thursday, September 07, 2006

Recovery from the little ice age?

One argument often heard in the AGW debate goes something like this:
The Earth may be warming, but human activities are not responsible: Even if the Earth is warming, it is obviously part of the continuing recovery from the “little ice age,” the cool period from the fifteenth to eighteenth centuries.
This argument tacitly assumes that the Earth’s climate system has a “normal” state that it pushes back to after unusually warm or cold periods, like a stretched spring returning to its normal length. While this might appear commonsensical, it has no foundation in either the record of how climate has varied or the fundamental physics of the atmosphere. The Earth’s climate has no “normal” state to which the climate seeks to return, so there is no reason to expect that an unusually cool period will be followed naturally by a return to warmer conditions.

Rather, when interpreting cause-and-effect in the temperature record, one has to consider the forcings. One can make a strong argument based on solar proxies (like sunspots) that the increasing temperature between the 17th century to about the middle of the 20th century was due to increasing solar forcing.

However, for the particularly rapid warming of the late 20th century, we have a good knowledge of the forcings of the climate. As I described here, we can eliminate solar variability as a primary driver. In fact, the only forcing that explains the warming is the increase in greenhouse gases.

In summary, there is no evidence that today’s particularly rapid warming is caused by the same thing as caused most of the warming over the last few centuries. By considering the forcings, we can conclude that most of the recent warming can be attrbituted to human activities. Thus, the argument that today's warming is simply a continuation of some natural trend is unsupported by any science.

Monday, September 04, 2006

A sensible position

Can be found here. I might have re-written the title, if I were the editor, but I generally agree with the sentiment expressed that both adaptation and mitigation will be necessary to deal with the climate change problem.

North on the hockey stick

My colleague Jerry North was the chair of the National Academy panel that investigated the hockey stick. Last week he gave an interesting seminar to our department about the experience. You can view the seminar here.

[Techincal details: it's a 40 MB file, so it'll take some bandwidth. It's in mp4 format --- if you have a recent version of quicktime on your computer, you should be able to view this. It runs just over an hour, so grab some popcorn and enjoy!]

Saturday, September 02, 2006

Fill in the blanks

Consider the following diatribe against the system that I found on the web:
If a contest were held to award the most scientifically baseless, politically oppressive, morally bankrupt, economically destructive environmental farce, the hands-down winner would be the theory of global warming.

Whenever a major action is being dictated, especially at the national level, you should ask yourself, "Who benefits?" If your answer includes arrogant "scientists," trendy politicians & faceless corporate bureaucrats, you can safely assume that scandal is not far behind. Obviously these do-gooders will proclaim that you are going to benefit because they are doing you a big favor; one you don't remember requesting. If you're starting to feel queasy, good.

When I began studying the theory that greenhouse gases were affecting the climate, I found less & less, not more, credibility. What I did find however is that people who will make money on this scandal support it, & choose to deny or ignore the facts. This trend continues at an accelerating pace.
This sounds like pretty routine stuff, right? Actually, I've edited a few words: the bold words have been replaced as follows:
  • "theory of global warming" was really "the banning of CFCs."
  • "greenhouse gases" was really "CFCs"
  • "climate" was "ozone layer"
The point here is that the arguments you hear about climate change are just a re-run of the arguments over ozone depletion. And when the next environmental issues comes up, just replace the bold words with whatever is necessary to attack the science of that issue. You see ... it's easy to be a "skeptic"!