October 1, 2007

Back When All News Wasn’t Bad

Filed under: Adaptation, Animals, Extinctions, Plants

In 1996, Camille Parmesan published a paper in Nature magazine that supposedly was the first documentation that animal species (in this case Edith’s Checkerspot Butterflies) were shifting there range because of presumably anthropogenic climate changes. Parmesan told the New York Times, “I cannot say that climate warming has caused the shift; what I can say is that it is exactly what is predicted by global warming scenarios…”

Parmesan went on to look at additional species and her work, and other studies like hers that document shifting species ranges as the climate warms, are treated as “blockbusters” when the appear, most often in the world’s most prestigious scientific journals such as Science and Nature. These are accompanied by press releases and widespread media coverage that undoubtedly reverberates with the (mock?) horror of environmentalists worldwide. In fact, some studies have even taken the shifting-range-is-bad concept a step further, projecting that a quarter to a third of all the world’s species will be extinct in 50 years. The lead author of one such study published in Nature magazine, British University of Leeds’ Chris Thomas, told the Washington Post, “We’re not talking about the occasional extinction—we’re talking about 1.25 million species. It’s a massive number.”

Time and time again we at World Climate Report counter that the earth’s climate is normally quite variable, and if the earth’s plants and animals were not able to shift their behaviors and viable ranges there would be quite a few less of them on the world today (a category that probably includes the species homo sapiens as well). So plants and animals responding to climate change is hardly unexpected or catastrophic—what would be potentially catastrophic would be the exact opposite situation, that is, if plants and animals were not shifting as the climate varied.

It is only in these overly politically correct times that we live in that a warming climate is considered to be a climate of catastrophe. Throughout all other periods in human history, it has been the other way around—cold times brought with them famine and disease, while warm times brought prosperity and growth. This change in thinking (warmer is bad, colder is better) has come about only within the past 20 years or so and since then has picked up quite a head of steam. Now, nary a raindrop falls nor a bolt of lightening strikes that isn’t pointed to as a sign that human-induced global warming is ruining the world.

In more level-headed times, indications that the climate was warming and that nature was responding in kind were typically greeted as indications of positive goings-on. For instance, back in 1948 noted Arctic scientist Hans Ahlmann wrote a lengthy discourse in The Geographical Journal of the Royal Geographic Society describing the current “climate improvement” that was then ongoing in the Arctic regions, as evidenced by rising temperatures, melting glaciers and changes in species ranges. Ahlmann contrasted these favorable developments with the “climate deterioration” that took place during the period from about 1300A.D. to the mid-19th century (the Little Ice Age) when temperatures dropped, glaciers advanced, and human settlements in northern climes suffered. We have touched on Ahlmann’s comments previously (see here).

Recently, we have come across another interesting article, this one published in 1968, that spoke in positive terms about the rapid northward movement of a large number of bird species across northern Eurasia that accompanied the warming temperature experienced there during the first part of the 20th century. Writing in the journal Arctic, M. Slessers described, without any hints of dread, the rapid expansion of various species:

It appears that, step by step, the tundra is advancing into the arctic desert, and the taiga is moving into the tundra. In line with plants, the mammals and birds are moving northward too. The prime cause of this race is the warming of the Arctic. The temperature data compiled by Vizes and others show that the warming trend has become clearly pronounced since the 1920’s in the arctic belt from Iceland and Spitsbergen to Taymyr and Severnaya Zemlya. The average difference in temperature between the beginning of this century and the 1950’s is about 7 deg. C. for winter, 5 deg. C. for autumn, and only about 1 deg. C. for the spring and summer.

As a consequence, the vegetation period is extended, and more birds and other animals as well are lured north. In this connection, Uspenskiy cites lemmings as an illustration since they constitute an important food item for larger birds and mammals.

During the most intense warming period on Yamal Peninsula in northwestern Siberia (1930 to 1949) the mass development of lemmings was observed every year, not once in three or four years, which is the usual cycle for the mammals in the area.

Because of such favourable conditions, some birds have extended their ranges northward by 2 degrees latitude (210 km. or 130 miles) during the last 50 years. The record for this area is held by the willow warbler (Phylloscopus trochilus), meadow pipit (Anthus pilaris) and possibly by the fieldfare (Turdus pratensis). The last-mentioned is extending its range not only northward but also westward. A permanent colony has recently been established in Greenland. This event is described in detail by Salomonsen, a Danish ornithologist, who has been observing fieldfares since their appearance in Greenland in 1937. Now they have also been observed on Baffin Island and the Labrador Peninsula.

Slessers goes on the describe in further detail how climate changes have led not just to changes in the northern limit of some birds, but to movements in the southern limits as well—movements which, if not viewed in their entirety, may give a false impression of species loss. For instance, across Europe there were many species that were once populous in a region, but which had become rarer. In Latvia and Estonia, for example, the number of willow ptarmigans had been reduced by nearly 90%—primarily because of an increase in mild winters and reduced snowfall. Other species were leaving the Baltic regions as the climate warmed as well —the snowy owl, the great snipe, the wood sandpiper, to name a few. But did Slessers bemoan this fact? Does he project widespread extinctions to occur? No. Instead he writes:

But this does not mean that the number of species is decreasing in the Baltic lands; not at all. There are many southern species that are moving in from Central Europe, the Balkans and the Ukraine.

The fastest immigrant is the collared turtle dove (Streptopelia decaocto). Starting out from the Balkans in the early 1930’s, the species had reached the Zakarparskaya region in the early 1940’s. In 1949 the bird was observed nesting on the north side of the Carpathian Mountains by Strautman. In 1950 it was breeding in Friesland, Germany, in 1954 in Denmark, L’vov and Kiyev; a few years later it was breeding in Lithuania and White Russia, thus moving northward with a 800 km.-wide front.

Another quick immigrant to northern areas is the serin (Serinus canaria). During the last 200 years this species has transferred its northern boundary from southern Europe to Estonia, a distance of about 1,500 km. These two leading immigrants are followed by many other southern species, such as the black redstart (Phoenicurus ochruros), corn bunting (Emberiza calandra), penduline tit (Remiz pendulinus), gadwall (Anas strepera) and others.

Nowhere is doom-and-gloom evident. There were no headlines generated from Slessers article proclaiming “Baltic Lands to Lose Their State Birds!” or “No Word in the Greenland Language For Fieldfare!” Contrast this with the fanfare that similar findings generate today—“A Baltimore Without Orioles? Study Says Global Warming May Rob Md., Other States of Their Official Birds” (Washington Post, March 4, 2002), or “No Word For Robin: Climate Change in the Canadian Arctic” (BBC, May 11, 2001).

It is a sad sign of the times when robins in the Arctic and northward moving butterflies are greeted with horror.

References:

Ahlmann, H.W., 1948. The present climate fluctuation. The Geographical Journal, 112, 165-193.

Parmesan, C., (1996). Climate and species’ range. Nature, 382, 765–766.

Slessers, M., 1968. Soviet Studies in the Northward Movement of Birds. Arctic, 21, 201-204. (http://pubs.aina.ucalgary.ca/arctic/Arctic21-3-201.pdf)

Thomas, C., et al., 2004, Extinction risk from climate change. Nature, 427, 145-148.




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