Thursday, February 17, 2011

Scientific consensus 1974


PBM said...

While global cooling graced the covers of a number of prominent magazine, it was never consensus among peer-reviewed science.

TJE said...

Not sure what you mean by consensus of science. Here are possibilities in rising order of possible controversy: 1. the climate is changing 2.the climate is changing with a contribution from human activity 3. the climate is changing and our models give us a complete and certain understanding of this extremely complex process 4. the climate is changing, our models give us a complete understanding of this extremely complex process and our other models give us very good understanding of the ecological and human consequences of this change 5. all of the above plus our other models give us good understanding of the costs, benefits, and highly complex interactive effects of possible policies. I think where environmentalists have gone wrong is taking a possible consensus on 1 & 2 and jumping the shark by pushing the idea that there is "scientific consensus" about 3, 4, and 5.

PBM said...

I don't disagree with that, I was just pointing out that there is a lack of peer reviewed science on global cooling and that it may have been something that was sensationalized by the media but not believed by a majority or even a significant amount of climatologists.

On points 3 and 4, I think that the article I put up before on extreme rain shows that scientists are beginning to understand complex climate processes and the effects climate changes can have on humans and the environment. While it's not a 100% understanding, I think the research is at least starting to connect the dots here.

Maggie said...

While there is a fair amount of uncertainty surrounding the magnitude of the ecological and social impacts of climate change, this uncertainty does not mean that policy geared to mitigate the effects of global warming is unwise.

Dr. Stephen H. Schneider wrote extensively on the issue of risk in developing climate change policy. Like many environmental scientists, he does not make the mistake of jumping to the conclusion that there is scientific consensus regarding the impacts of climate change and climate change policies, as you suggest. Instead, he focuses on how to evaluate risks in addressing climate change policy. In "Climate Change Science and Policy," Schneider describes Type I and Type II errors: "If governments were to apply the precautionary principle and act now to mitigate risks of climate change, they would be said to be committing a Type I error if their worries about climate change proved exaggerated and their investments in hedging strategies were considerable. A Type II error would occur if serious climate change materialized after insufficient hedging action."

I agree with your statement that there is uncertainty surrounding 3, 4 and 5. However, this uncertainty is not an excuse to do nothing. Given the broad scientific consensus on 1 and 2 (See IPCC Fourth Assessment Report: Climate Change 2007), Schneider suggests that neglecting to enact climate change policy and facing the severe consequences of global warming later on would be a far more costly outcome than if policymakers were to invest in climate change policy now and then realize that global warming was not as harmful as they thought (a Type I error). Acting in the face of uncertainty is a necessary component of policymaking, and I would argue that given what we know of the potential risks of global warming, as well as our experience with market-based regulations to control air pollutants, we have more than enough reason to conclude that the implementation of such programs to mitigate the effects of climate change is a smart policy decision.

While I do agree that some environmentalists act as though they are certain when they are not, the majority of intellectuals pushing for climate change policy acknowledge the inherent risks and arrive at their conclusions through a careful process of weighing costs, benefits, and uncertainties.

TJE said...

Maggie, you are exactly right! The question then becomes: What do we do when we face a situation of great but very uncertain risk. A friend of mine (and a Hamilton grad) wrote a very good book on this very subject:

If someone asked me: In the face of this uncertain risk, should we embark on a complex regulatory scheme to fundamentally alter the world economy and perhaps reduce world economic growth by 1-2% a year: my answer would be no. But in the face of such risk, we might focus on policies that we know are good in any event-- reducing our reliance on foreign sources of energy, investing in r&d for tranformative technologies, investing in the infrastructure for technologies to help smooth the transition when we run out of oil in the not too distant future. Over the long term. I have more faith in market forces than government planning.

TJE said...

PS. Another good book:

In the not so long run, markets will adjust to the coming end of oil. Government has a role to play in the process but that role should be limited and targeted.

In some ways, I fear, the politics of apocalypse over climate change has gotten in the way of smart thinking about the role of government.

Maggie said...


I completely agree that it is necessary to reduce our dependence on oil and that markets will adjust to this transition. But we cannot ignore that the principal contributor to CO2 emissions is coal, which is primarily used in coal-fired power plants (which produce over half of our nation's electricity). Because coal is abundant and relatively inexpensive, market forces will not drive a transition toward cleaner energy sources in the power industry. Thus, I do believe that a necessary role for government is to provide incentives for power plants to invest in new, cleaner technologies or technologies that capture and store carbon after combustion (CCS). This is what the EPA intends to do under the Clean Air Act.

Furthermore, past experiences with market-based regulations for limiting other pollutants (such as NOx and SO2) show that cap-and-trade can be effective and drive innovation. Many have expressed concerns over allowance price volatility under quantity caps; however, new emissions trading programs may implement cost containment mechanisms, which have been successful at solving these issues.

TJE said...

1. Do you also want to impose such restrictions on developing nations? If yes, aren't we dooming them to poverty. If no, wouldn't our efforts be a drop in the bucket.

2. My understanding is that cap and trade worked relatively well with acid rain in US, not so well with CO2 in Europe.

3. NY and PA could be the Saudi Arabia of natural gas, a clean fuel. Do you support safe fracking?

Maggie said...

1. According to the CDIAC's latest estimates, the U.S. contributes to 20% of the world's CO2 emissions. I don't think this is just a drop in the bucket. Furthermore, as the most powerful country in the world, we should be setting the example for other countries to follow.

2. The Acid Rain program was considered a success because it did achieve the reductions cap. However, from an economist's perspective, compliance costs to firms could be further minimized by lowering the emissions cap even farther so that the marginal cost of abatement equaled the marginal health/environmental benefit. This suggests that a CO2 program could be even more successful than the SO2 one if designed properly.

I don't know that much about the EU Emissions Trading Scheme, but I do know that one of the problems with it was, as I mentioned before, allowance price volatility. I just read a paper about cost-containment mechanisms that aim to solve this issue, and it looks promising. While more research is necessary to determine which mechanisms work best, cost containment seems to be a viable solution to some of the problems faced with the EU-ETS. The three main options are banking and borrowing of allowances, hybrid approaches that combine price based instruments with quantity based ones (essentially taxing v. trading) and offsets.

3. I don't know much about the pros and cons of fracking. I'm going to do some research on the subject and I'll get back to you!

TJE said...