April 01, 2010

Duane Griffin, associate professor of geography.

LEWISBURG, Pa. — Welcome again to "Ask the Experts," a regular web feature that highlights the expertise of various Bucknellians in a range of topics related to current news events and other timely subjects. || Ask the Experts archive

This week, we asked Duane Griffin, associate professor of geography, to talk about global warming and its impact on the planet, whether it can be reversed and some simple measures all can take to help reduce its impact.

Q: How much of a crisis is global warming?

A: We recognize crises concentrated in space and time — Hurricane Katrina or the Haitian earthquake — but miss those that are chronic, diffuse and far away. Climate change is a very slow-moving, diffuse and mostly invisible crisis.

The Global Humanitarian Forum, headed by Kofi Annan, analyzed worldwide losses from natural hazards over the past 25 years. By their estimate, about 300,000 more people die each year from climate-related hazards than would be the case if climate weren't changing. They also estimate that around 20 million people have been displaced and another 800 million have been severely affected by or are at extreme risk from climate-related hazards. Even if their estimates are 10 times too high, this represents suffering and loss on par with Darfur, which is most definitely a crisis.

Q: What is the debate about global warming?

A: Debate over global warming has really been a series of debates on three questions: first, is it real; second, are humans to blame; and third, can or should we do anything about it? All three debates rage in the public realm, but within the scientific community, the first two are pretty much resolved.

The evidence for warming is clear: Earth's surface is about 1.5 degree warmer than it was in 1900. Are humans responsible for that warming? The physics behind the greenhouse effect are pretty simple and they tell us that more greenhouse gases should cause temperatures to rise. And we see exactly that relationship in ice cores and other records of past climate. We know that we've increased CO2 levels by about 36 percent since the start of the industrial revolution, mostly by burning fossil fuels and through land use changes. If we combine those impacts with natural climate forcing factors, we can explain the temperature changes and even duplicate them using climate models. But if we take out the human impacts, the warming trend disappears.

Global warming skeptics have focused on raising doubts about the certainty of our current understanding of global warming, which is easy to do, because science always includes some degree of uncertainty. But they haven't been able to come up with alternative explanations for the warming that would let human impacts off the hook and they don't have any predictive models that suggest we're not headed for trouble.

In short, we're almost dead certain that temperatures are rising, that they'll continue to rise, and that we're responsible. So, the third question — Can and should we do anything about it? — is where the debate really needs to be focused.

Whatever we do will involve some combination of trying to mitigate our impact and adapting to the changes as they occur. Adaptation will probably be more expensive in the long run and the costs will be both economic and humanitarian. Mitigation will probably cost more in the short run, though the longer-term health and economic benefits from developing sustainable energy sources, reducing air pollution, and so on, will probably be substantial.

We don't have a very good track record at long-term planning, especially in the face of uncertainty about the future, and our best projections for future climate are based on computer models, which might turn out to be wrong. And so far, they have been wrong, but not in the direction we'd like. According to the models, we shouldn't have seen a free passage through the Arctic Ocean, for example, until mid-century, but it happened in 2007. Beyond surprises like that, we're seeing reality track along the worst-case scenarios that the models predict. If we keep it up, things look really bleak for 2050 and beyond.

Q: Can global warming be reversed?

A: It can't be reversed any time soon. Just with the CO2 that's already in the atmosphere we're already committed to more warming. But we can slow the increase and try to avoid catastrophic warming.

Five years ago, Robert Socolow and Stephen Pacala, a Lewisburg native, proposed a strategy for stabilizing CO2 levels that they call "stabilization wedges." If you graph where atmospheric CO2 concentrations are headed in the next 50 years, then graph where we'd like them to be, you get a triangle-shaped gap between the two.

You can break that gap into three "wedges" that represent increasing use of alternative energy sources, energy efficiency and conservation, and CO2 capture and storage. New technologies could add even more wedges, but their point is that we already have the technology we need to make this happen and we don't even need to change our lifestyles much. But there's very little economic incentive and pretty much zero political will to change what we're doing now.

Q: What are some simple measures we can take to reduce global warming?

A: Conservation and efficiency are really the only option for simple measures at this point, and these are easier and more lucrative than most people realize.

A couple of years ago, we cut our electric bill from more than $100 a month to less than $40. We switched to fluorescent bulbs, set up clothes lines in the basement and outside to minimize using the drier, and a few other things. We also started paying our kids the difference between each month's electric bill and what it had been the previous year.

We were wasting a lot of energy and money on things like leaving lights on in empty rooms and, in the case of my kids, pretty much the entire house, and otherwise not thinking. The instructions on a box of pasta, for example, call for about three times as much water as you actually need to cook the pasta. So, by blindly following the instructions, cooking pasta costs three times as much money and emits three times as much CO2. We stopped doing things like that.

By thinking a little bit and sacrificing some minor convenience, we saved nearly $1,000 over the course of a year. Scale that up to every household in the United States and you've made a pretty big impact and saved a lot of money.

That said, residential use only accounts for about 20 percent of the U.S. total energy use, and alternative energy and CO2 sequestration aren't going to happen without broad-scale policy changes, and there's very little political will to do that, especially now. So, really, the simplest thing we each can do is hound our elected representatives to work on solutions at the state and national levels. Like turning off the lights, it's incredibly simple, but most of us don't bother.


New editions of "Ask the Experts" will appear on the Bucknell website on most Thursdays during the fall and spring semesters and on occasion throughout the summer. If you have ideas for future questions or are a faculty or staff member who would like to participate, please contact Sam Alcorn.

To learn more about faculty and staff experts who can speak on a variety of news topics, visit Bucknell's searchable Experts Guide.

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