Consider these quotes from two climate scientists:
"In our models, it's difficult to understand how a 1-degree Fahrenheit warmer sea can spawn the ... rather significant increase that we've seen in Category 4 and 5 hurricanes. Therefore, we can't put it all together. ... But the notion that a warmer Earth could cause more hurricanes, certainly that would be predicted by the climate scientists."
"Yet how can a barely discernible, 1-degree increase in the recorded global mean temperature since the late 19th Century possibly gain public acceptance as the source of recent weather catastrophes? And how can it translate into unlikely claims about future catastrophes?"
Despite covering much the same territory, these statements come from two people with wildly different perspectives on climate change, with huge implications for public policy. They illustrate how the same basic facts can be interpreted in different ways, and for different ends; one scientist believes that we can and must address climate change despite what we don't know, while the other doesn't believe that the evidence merits action.
The first quote comes from Jerald Schnoor, a professor of civil and environmental engineering at the University of Iowa, chair of the Iowa Climate Change Advisory Council, and editor of the journal Environmental Science & Technology. In an interview last week, Schnoor outlined how the recommendations of the Iowa Climate Change Advisory Council could reduce greenhouse-gas emissions in the state by at least 50 percent by 2050.
The second comes from Richard Lindzen, a professor of atmospheric science at MIT, from a 2006 commentary he wrote for the Wall Street Journal. He is one of the leading scientific critics of climate-change "alarmism."
In the same commentary (OpinionJournal.com/extra/?id=110008220), Lindzen notes that while there is consensus on three basic climate-change facts - that it has occurred, that there is significantly more carbon dioxide in the environment, and that carbon dioxide "should contribute to global warming" - he emphasizes that "what the public fails to grasp is that the claims neither constitute support for alarm nor establish man's responsibility for the small amount of warming that has occurred."
He also writes that "ambiguous scientific statements about climate are hyped by those with a vested interest in alarm, thus raising the political stakes for policy makers who provide funds for more science research to feed more alarm to increase the political stakes."
Lindzen is arguing that much environmental public policy is based on false (or unverified) assumptions about climate change.
Schnoor said that Lindzen has strong credentials but said he's in a small minority of skeptics.
"Among scientists, there are very few in the skeptical category," Schnoor said. "That's not to say there's not uncertainty, and not to say that there aren't things that we don't fully understand. ... But we know enough about the major factors that drive our climate and the heat balance on Earth ... to say with some certainty ... that humans are involved in driving climate change."
A vast majority of climate scientists, he said, believe that "the warming that we've had in recent years - let's say the past 50 years or so - is really quite dramatic in terms of ... other [historical climate] changes ... , and we have pretty good evidence that it's caused mostly by human emissions of fossil fuels ... when we burn those."
He noted that the 2007 Fourth Assessment Report (http://www.IPCC.ch/ipccreports/ar4-syr.htm) of the Intergovernmental Panel on Climate Change was approved by roughly 180 countries and several thousand scientists. "To me it's actually a fairly conservative report, in the sense that to get that many people to sign, you have to have a broad consensus about what's in there," he said. The report concludes that "a great majority of the warming that we've seen is due to human emissions," Schnoor said.
That point of view is reflected on a policy level through his work chairing the Iowa Climate Change Advisory Council (Iowa.DNR.com/iccac), a 27-member body that has been meeting since fall 2007 and will deliver a report to the governor and legislature in December.
Although it includes members from such diverse interests as the Sierra Club, the Iowa Farm Bureau, and utility companies, Schnoor said that "it's been less contentious than I might have thought.
"The group has come up with more options than we need to get steep cuts in our emissions. Some of them seem to have low or even negative costs associated with them. They should save us money, create jobs, and help the economy of the state to prosper."
The council will set emissions goals for 2012 and 2020, Schnoor said, and it will sketch out scenarios to reduce emission by 50 percent and 90 percent (compared to 2005) by 2050.
Schnoor said many ideas are cost-effective, such as enforcing and revising building codes to emphasize energy efficiency. "Those things pay for themselves and save money," he said.
Enhanced conservation tillage and no-till farming, he noted, would allow farmers to sell carbon credits in a cap-and-trade system, which would limit carbon emissions and allow entities that reduce emissions to sell credits to those that exceed emission requirements. Midwestern governors signed the Midwest Greenhosue Gas Accord (MidwesternGovernors.org/govenergynov.htm) in 2007.
That "polluter pays" principle puts a price on environmental degradation, he said: "We're doing nothing short of revolutionizing the economy."
A cap-and-trade system, he added, is also attractive because it doesn't dictate how a reduction in emissions is achieved: "The market will determine how best to reduce it."
Schnoor also said he believes that there are political solutions to environmental problems. "Policy really does work most of the time," he said.
While federal and state ethanol subsidies are problematic because corn is not as efficient as other biomass to make the fuel, he said, those incentives work toward something better. "Ethanol has many problems the way we're doing it now," he said. "But we can do better ... I think what we're doing now has created the infrastructure to take us to a better place environmentally."
In the long run, he said, as technology progresses, we'll use "cellulosic" sources to create the fuel - which will require fewer fossil-fuel inputs in production.
While Schnoor said he's optimistic, there are barriers. Climate change is abstract and long-term, and it often takes a back seat to other issues.
"That's pretty difficult for people to deal with when they're bombarded on a daily basis with the meltdown of the financial markets and the subprime-mortgage crisis," he said. "Do I worry about a global depression next week, or do I worry more about global warming 50 years from now?"
Another critical public-policy question is whether policy should prepare for a catastrophic but unlikely climate change that might result from the breaking and slipping of ice sheets into the ocean, which Schnoor said could raise sea level anywhere from 30 to 80 feet within a few years. "We think it's a low probability of that, but the consequences are quite great," he said.
