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Is the Sky Falling?

By Sally Jongsma

People come to this issue, as they do to all issues, with their presuppositions,” says Dr. Doug Allen of Dordt’s physics department. “Worldviews influence how we filter scientific ‘data.’ ” He quotes Dr. Roy Clouser: “Virtually all the major disagreements between rival theories in the sciences and in philosophy can be ultimately traced to the differences between the religious beliefs that guide them.” (R. Clouser, The Myth of Religious Neutrality).

“It’s important to be honest about that as we sort through the data,” Allen says.

Allen knows he brings his own religious and political presuppositions to the research he’s been doing on global climate change. It is part of being human, he says. But while it is impossible to be totally objective, he is trying to focus on what scientists know about climate change and the certainty with which they know it.

Allen has become known on campus for his interest in and knowledge about the sky. E-mails from him alert the campus community to interesting star-gazing opportunities—the most recent being Comet McNaught in January. Sometimes he readies the telescopes and invites anyone interested to view the heavens; other times he gives directions about when and where in the sky to look for comets, meteor showers, or northern lights.

Dr. Doug Allen

Dr. Doug Allen

Allen studied physics as an undergraduate at Wheaton College, thinking he would study theoretical particle physics in graduate school. But while at Iowa State University, he decided he wanted to apply physics to environmental issues. His work with the stratosphere eventually landed him a research position with the Navy, studying meteorology. There he learned much about mathematical modeling and how it helps researchers link causes and effects. After he came to Dordt in 2005, he continued his work with the Navy, collaborating on a NASA research project. He also began analyzing research done by others to better understand climate change and its effects.

“I feel obligated to be engaged in studying issues like this,” says Allen, who believes that caring for the world God created is one part of his responsibility as a Christian. “We need Christian experts to dialogue to try to arrive at concrete policy recommendations.” At this point it is not clear to him exactly what those recommendations would be. He knows there are no simple solutions and tries not to align himself with one “side” or the other as he immerses himself in research.

Last November Allen was invited to participate in a panel discussion at Wheaton College titled “Global Climate Change: A Faithful Response,” sponsored by Wheaton’s Center for Applied Christian Ethics. Allen’s presentation was titled “Is the Sky Falling? A Brief Overview of Climate Change Science.”

“Global climate change is scientifically complex,” says Allen. He knows that most people would like a two or three sentence answer to the question “What do you think about global warming?” In his soft-spoken, gentle way, he’d like to reply, “Do you have thirty minutes—or better yet two hours?” He also realizes that not everyone can take the time needed to understand all there is to know about such issues, and they need to rely on people they trust for their information.

As a scientist he also deals with issues differently than a politician or journalist might.

“Scientists want to be cautious, certain about their conclusions before they make final judgments or policy recommendations,” he says, adding, “Their reputations are on the line.” Politicians, policy makers, and activists, on the other hand, are willing to live with more uncertainty, and the public tends to be more forgiving if they speak or act more hastily.

For his panel presentation, Allen tried to show what scientists know about climate change, where information gets exaggerated or stretched, and where it is scientifically certain. “Scientific papers tend to be conservative,” he says. Scientists do not publish unless they are convinced that they have something that will withstand peer review.

Allen admits that there may be times when people should act before they are completely certain about the data, but he believes it is his job and that of scientists in general to try to distance themselves from policy decisions and do the research that allows other leaders to make good decisions.

On the panel in which he participated, he was joined by an economist who explored how the effects of global climate change could affect the world economy, an ecologist who described how it could affect global health, a political scientist who talked about how it could affect international relations, and a biochemist who moderated the discussion. The complexity of the issue became clear as people approached it from their particular areas of expertise. Allen and Environmental Studies Professor Matthew Stutz later took seven Dordt students to a follow-up student conference at Wheaton on creation care that will help them come to their own conclusions about how they should care for the world God made.

“For Christians, this is an important issue, because God has entrusted the earth to our care,” says Allen. “As stewards we are obligated to be engaged and think carefully about how our actions affect the creation and its people.”

Is the best way to be a good steward to cut back on what we consume, or is it to further develop resources to make more energy available to developing countries and help lift them out of poverty? And what are the economic and political consequences of these and other actions?

Allen is a conservationist in the personal choices he makes, and he believes that Christians need to be involved in public policy. If the effects of global climate change are as big as people say, it will be the defining issue for our generation, and Christians should be helping shape the response, he believes.

What Scientists Know

The fact that the global average surface temperature has increased by about one degree Fahrenheit in the last century is not disputed, says Allen. Similarly, all scientists agree that CO2 levels in the atmosphere have increased.

Some in the scientific community do disagree about whether temperature increases are because of increased CO2 levels and some disagree about how the changing climate will affect the future. “There is a consensus that global surface temperatures will continue to increase, but predictions about the amount of that increase vary,” Allen says.

The fact that humans could be changing the environment on a global scale is rather staggering to Allen, who knows how much effort it takes to bring such change. “We noticed it first in ozone depletion and now in temperatures rising,” he says.

He cites statistics that back up his statements. Over the last thousand years, there was a slight decrease in average temperatures for the first 900 years and then a rapid change in the last 100 years. From 1860 to 1920 average temperatures were steady; between 1910 and 1940 temperatures increased slightly. From 1940 to 1970 they again decreased slightly; from 1970 to the present they have shown a strong increase, with the 1990s being the warmest decade in the millennium and 2006 the warmest year on record.

Allen says that the climate change debate is confusing for several reasons:

• Climate changes occur over long a time so we need long-term data records to discern trends.

• Climate change trends are smaller than normal weather fluctuations so we need good statistics.

• The atmosphere-ocean system is very complicated so we need computer models.

• Projections depend on uncertain human actions so we need to develop plausible scenarios.

• No one can be an expert on all areas of the debate so we need to decide who to trust.

He believes that scientists must also provide accurate information about the likely magnitude, causes, and projections of global climate change; they must be up front about the assumptions they make and tell people how certain they are of their conclusions; and they must use the peer-review process to test their conclusions, provide results that are reproducible and refutable, and provide quantitative results, not anecdotal evidence.

Following his own advice and using research data from the Intergovernmental Panel on Climate Change (IPCC; www.ipcc.ch), he says scientists are virtually certain (99%) that global average sea level has risen from ten to twenty centimeters (2.5 – 5 inches) and that there has been a widespread retreat of mountain glaciers. It is very likely (90-99%) that there has been a two-week reduction in the annual lake and river ice cover in Northern Hemisphere mid- and high latitudes. It is likely (66-90%) that

• the arctic summer sea-ice decreased ten to fifteen percent since the 1950s,

• the global ocean temperature increased since the late 1950s,

• land surface rainfall has increased,

• and cloud cover over land has increased.

Allen notes that climate change can be caused by several things: earth’s orbital variations, tectonic activity, volcanoes, solar variability (although the sun’s output has been steady over the last twenty-five years), internal variability, and human activity (greenhouse effect and aerosols).

The greenhouse effect, essential to keeping the temperature in the atmosphere from being too cold for life, has changed the most since 1970. Between 1940 and 1970 sulfate aerosols may have contributed to the cooling trend by reflecting sunlight back to space. More recently greenhouse gases have thickened the blanket, raising temperatures. Concentrations of carbon dioxide have increased thirty percent over pre-industrial levels, nitrous oxide sixteen percent, and methane 200 -percent.

Computer models, simulating laws of chemistry and physics, take this data and make predictions about the impacts of these changes. All models project increased warming—from 1.7 to 4.2 degrees Celsius by 2100—and rising sea levels of four to thirty-six inches.

“Not all effects will be negative for all regions,” says Allen, who adds that it is difficult to predict how specific regions will be affected. One thing that is likely, however, is that poor people will be more affected than wealthy ones because they often live in more vulnerable areas and because they have fewer resources to deal with change. He believes it is reasonable to expect more droughts in some areas and more rain in others, as well as rising sea levels.

Allen is still hesitant to draw too many conclusions about policy recommendations, but he does believe it is important to have an open mind that allows us to adjust our thinking based on what we can learn. “God calls us to steward his creation and to care for the poor,” says Allen. These responsibilities should shape the kinds of policies we promote.