Werner Discusses New Climate Change Study

Monday, October 15, 2012 - 10:15
Professor Alan Werner

Alan Werner, professor of geology, is a coauthor of a new study published in Geology that is helping quash claims that climate change is solely the result of changes in the natural climate system. Werner and his team have collected and analyzed lake sediment samples in the area of Svalbard, Norway, to build a detailed record of the summer temperatures of this region for the past 1,800 years.

Questioning Authority spoke with Werner about the study and the implications of the research findings.

Questioning Authority: Tell us about the research project and your main findings.

Werner: The climate on Svalbard has been monitored since 1906. This represents one of the longest and best-quality climate records in the high Arctic. But, it tells us nothing about climate conditions during the previous millennia.

To reconstruct climate during these prehistoric times, a climate proxy is needed—something in the geologic archive that can be used as a reliable surrogate for past conditions. There are lots of different climate proxies; some chemical, some physical, and some biological. In this study we used alkenones (an unsaturated fat made by algae) in lake sediment cores to reconstruct past summer temperatures. Previous research has shown that in colder water algae make more unsaturated fats, and in warmer water algae make more saturated fats.

Our results indicate that the current warming—starting 50 years ago—experienced in Svalbard is significantly greater than the warming experienced in the region over the past 1,800 years, including during the Medieval Warm Period.

QA: The Medieval Warm Period has been used as evidence by skeptics that climate change is not caused by humans. What was that argument?

AW: Climate change is well-known in the geologic record. Even during human history, climate change has been documented. Two events that humans have lived through include the Medieval Warm Period (950-1250 AD) and the Little Ice Age (eighteenth and nineteenth centuries). These two events predate the Industrial Revolution and, thereby, direct human influence. These events have been used by climate change skeptics as evidence that recent warming is likely just another one of these natural cycles. The implication of this argument is that humans are not to blame for the recent warming, and the climate will once again cool as it did subsequent to the Medieval Warm Period.

QA: And how does your research change the relevance of that argument?

AW: Our research results suggest that although the Medieval Warm Period was a time of relative warmth in the Arctic, it is dwarfed by recent warming. Many climate change researchers believe that the Earth is warmer than at any other time in the last 2,000 years—as confirmed by our results—and that we are headed towards an even warmer world.

QA: How long have you been involved in this research project? And why in Svalbard?

AW: I did my Ph.D. research on Svalbard and then with colleagues I decided it would be a great place to run an NSF-funded Research Experience for Undergraduates (REU) field site. Nearly every summer colleagues and I take students into the field and teach them how to conduct Arctic fieldwork.

Svalbard is one of the most accessible high Arctic field sites and we know from previous work that its climate has changed; what we didn’t know is how and when it changed. Our research sheds light on these climate events.

QA: So what, in terms of climate and geological changes, is actually happening in the Arctic regions right now?

AW: The Arctic is warming more than two times faster than lower latitudes. When the white snow and ice disappears, fewer sun rays are reflected out and, instead, the heat is absorbed by land and sea—resulting in accelerated warming.

Besides increasing air temperatures, probably the biggest change is in the Arctic Ocean sea ice cover. With the lowest ice cover ever recorded this summer, the usually frozen Northwest Passage is likely to open up on an annual basis. Without its ice cover, the Arctic Ocean will absorb more heat in the summer and release more heat and moisture in the winter, which will promote further warming. Other concerns include changes to the ecology of the Arctic and the melting of the land-based permafrost. A recent study just reported that even the deep oceans are showing signs of warming!

QA: Do you expect this current warming to continue?

AW: I wish I could say otherwise, but yes, the warming and the associated changes are likely to continue. How can I be so certain? The residence time (lifetime) of a molecule of carbon dioxide (CO2) in the atmosphere is on the order of centuries, which means that even if we stop greenhouse gas emissions tomorrow, CO2 levels will continue to rise and then plateau at a high level.

Second, we are fundamentally changing parts of the climate system; many of these changes cannot be easily or quickly undone. As we continue to lose the Arctic sea ice, we will change the nature of weather patterns. And as we continue to melt the permafrost, we will release vast amounts of methane and carbon dioxide from the northern peatlands, which will drive more warming. And most disturbing, if we exploit and bring to market just the proven fossil fuel reserves (these are the known energy resources), we will push CO2 levels far beyond the acceptable limit of 350 parts per million (we are currently at 394ppm). And the greatest irony is that fossil fuels are finite, many experts believe we have already passed peak oil, and while coal will last a bit longer, neither is the long-term energy source we will need for the future.

QA: If we are stuck with climate change, why should we worry about making changes?

AW: The simple answer is that by reducing the amount of greenhouse gas emissions we can slow the rate of climate and environmental change and the ultimate amount of CO2 we put into the atmosphere. Simply put, what we do now matters with respect to the timing and magnitude of the issue.

QA: What can we expect in the future, in terms of implications of climate change?

AW: It’s not good. We’ll see overall higher temperatures, more heat waves, increased drought in some locations and flooding in others, stronger storms, rise in sea level, more water supply issues, fewer days of snow, and a spread of invasive species and insect-borne illnesses, just to name a few.

QA: Will climate change be an issue in the November election?

AW: “Immediate” issues—the economy, defense, and immigration—get placed on the front burner and less immediate issues like climate change get placed on the back burner.

And to make matters, worse the climate issue is wrapped up with energy, and energy is wrapped up with international trade, jobs, energy independence, and the economy—all of which seem to be more immediate and more important than the climate issue of the next decades. Yet the further we drive down this road, the more we aggravate the issue. Sadly, I think that it will take some pretty significant events before the climate issue is moved to the front burner.
 

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