Questions and Answers About Climate Change

THE CITIZEN SCIENTIST ( web page for important graphs and a satellite image of the Bering Glacier.)

Last year I attended a science conference in Fairbanks, Alaska, where I heard much about the problem of thawing tundra. I distinctly recall a drive along a formerly flat road that had dips caused by thawed permafrost.

That road was on my mind recently when I looked at some remarkable photographs of shrinking glaciers at World View of Global Warming. This site shows how some glaciers that once filled entire mountain valleys have nearly disappeared. Photographs on this site show how tundra has been thawing in Alaska and Sweden.

I also looked at a satellite image of the largest glacier in North America, Alaska’s Bering Glacier at NASA’s Earth Observatory web site (Fig. 1). According to the Earth Observatory site, “Warmer temperatures and changes in precipitation over the past century have thinned the Bering Glacier by several hundred meters. Since 1900 the terminus has retreated as much as 12 km.”

Then today Ralph Coppola’s “Wanderings” column arrived with this item: “John L. Daly’s site lists sets of historical temperature graphs from many stations around the globe.” This seemed like an interesting site to visit, which I did.

While numerous global warming web sites make their point with photographs of disappearing glaciers, Daly makes his with a staggering array of graphs and data about the world’s climate. The most significant aspect of his site are its many plots of temperature from many rural weather stations around the world. These sites are important, for they are much less susceptible to local and urban warming effects than the majority of weather stations.

I looked for temperature records for sites near the Bering Glacier, which is located in the southeast corner of Alaska near the coast. Fortunately, temperature has been recorded at two sites on either side of the glacier, Cordova and Yakutat (Fig. 2). Figure 3 shows the data for both sites since 1909. The Earth Observatory site reports that the Bering Glacier has thinned because of warmer temperatures, but the plots in Figure 2 don’t seem to show an obvious warming trend.

It’s well known that dust and carbon particles can greatly reduce the albedo (reflectance) of snow and ice, thereby increasing the absorption of sunlight. NASA’s James Hansen has shown that soot alone may be causing significant melting of global ice and snow. Besides soot produced from human activity, including the burning of fossil fuels and large scale burning for agricultural purposes around the world, there is also soot from massive forest fires in Alaska, Canada and Russia. The possible role of soot in melting glaciers might someday be viewed as a major discovery, particularly if it explains the melting of glaciers, such as Bering Glacier, in the absence of any warming trends. Deposition of dust from huge wind storms in Africa and China may also play a role.

Meanwhile, John Daly’s web site claims that there are comparatively few indications of significant warming or cooling trends in most of the numerous time series it shows from around the world. This seems even to apply to a remarkable temperature series from Central England that extends from 1720 to 1998 (see Fig. 4). While there has been a warming at this site in recent decades, Daly points out that the measurements are subject to urban heat island effects, for they are collected from a heavily urbanized region.

An especially interesting chart shows the temperature measured since 1869 at Valentia on the southwest tip of Ireland (see Fig. 5). Daly believes this site is significant because it has been well maintained, and because, “…it is the first point of contact in Europe for the Gulf Stream.” Figure 5 also plots the temperature at the Shannon Airport. He attributes the gradual increase in the Shannon temperature to urban development, a factor that is not significant at the Valentia site.

There is much more of this at Daly’s web site, including a troubling discussion of how questionable data from some temperature sites in strange locations are used in global climate models. He even shows a photograph of one such site directly adjacent to a parking lot.

What’s going on here? Countless web sites cover various sides of the global warming issue, but few seem to cover all the sides. Are time series plots of average temperature as meaningful as those that show minimum and maximum temperatures? Why doesn’t Daly’s site include a photo album of melting glaciers? Do any of the glacier sites show temperature records or present James Hansen’s findings about soot?

Perhaps it’s time for serious citizen scientists to examine global warming issues. One objective might be to develop a comprehensive web site that covers all sides of the warming issue, including the controversies. As for the science, the web is filled with data about every side of the issue, so it will not be necessary to begin a data collection program.

The Bering Glacier paradox is a good starting point. Figure 2 provides the temperature record, and a PDF report by Wendell Tangborn provides plenty of background information about the glacier and its surges. Another good project could be a study of why tundra is thawing. If soot explains the melting of glaciers where no warming is evident, what accounts for the thawing of frozen soil in Alaska and Sweden? Plots showing the annual temperature at Fairbanks, Alaska, since 1930 are available at John Daly’s web site, and they seem to offer an important clue. Fairbanks has grown considerably since I spent four years in Alaska as a child. Growth inevitably brings local warming, and the temperature plots seem to show this.

Citizen scientists who conduct serious global warming studies are encouraged to submit their findings for publication as feature articles in The Citizen Scientist. General comments, tips and ideas can be sent as e-mails to “Backscatter.”