Today’s editorial in the NYTimes, Climate Change and the Plight of the Whitebark Pine is a fine example of how a scientific fad (call it a meme if you like) gains and keeps traction. In this case, the fad is global warming. The editorial describes how the whitebark pine, a crucial element of high altitude mountain ecosystems, is in danger of extinction, and what will be the serious consequences for wildlife and vegetation if that comes to pass. The editorial clearly links the situation to global warming by way of the mountain pine beetle:
Historically, the pine’s defense against the beetle is living where conditions are too cold for it — at high altitude or at high latitudes. But as the climate warms, that defense has failed catastrophically… The tragedy is the ongoing demise of an ecosystem, one for which humans are culpable.
Looking into the scientific investigations of this issue, the link to climate change, not to mention climate change caused by human activity, is not at all clear. A study by the Canadian government quoted in the editorial concluded:
[the threats] include an invasive, foreign fungus and the suppression of forest fires, which are important in establishing pure stands of whitebark pine. But the most important threat is the spread of the native mountain pine beetle, which tunnels into the tree and lays its eggs under the bark.
The fungus is ‘blister rust,’ introduced from Europe. Note that climate change is not directly linked to the problem, and that the threats cited are well-known, long-standing, serious, and similar to threats faced by many ecosystems today: exotic species; human intervention in the eco-dynamics; local pests.
A Google search for whitebark pine and climate returns a lot of hits, but most of them are from the popular, environmental press. The logic of their statements is consistent and revealing. Warmer winter temperatures during the last decade have supported a vigorous growth in the beetle population, and that has decimated the trees. But what caused the warming? And how much warmer has it been? There is no discussion of this. Only statements such as:
So as long as temperatures keep rising and the beetles continue to be driven to higher-elevation habitats, their assault on the trees will continue. To save the species, a massive and immediate reduction in greenhouse gases is necessary. Source
Certainly there were outbreaks of mountain pine beetle in Whitebark in the ’30s and ’70s, but nothing like what’s happened in the last decade. Moreover, Dr. Logan’s climate models predicted this outbreak long ago. Very simply, warmer winter temperatures and longer summers have created overwhelmingly favorable conditions for a widespread pine beetle infestation in a high alpine tree species that used to be able to rely on cold temperatures to keep beetles at bay. Source
So, what do we actually know? We know that the whitebark pine is important for western ecosystems. We know that the trees are dying at a great rate. We know that they are dying because of a variety of factors, several of which have nothing to do with anthropogenic climate warming (AGW), and we know that one factor, the beetles, is extremely important and that it has been encouraged by warmer winters over the last several years. The link to AGW is assumed, as usual.
Climates, local and global, vary. There is no evidence that this forest catastrophe is more than a conjunction of several negative factors, several of them associated with human activity (importation of fungus, suppression of forest fires) and recent weather. Simply because the events are consistent with the hypothesis of AGW, it is automatically assumed that the proof is given, and the press goes to work. They are totally separate issues.
Consider the abstract to this article that is linked to this topic in many online searches (my emphasis):
Forest insects and pathogens are the most pervasive and important agents of disturbance in North American forests, affecting an area almost 50 times larger than fire and with an economic impact nearly five times as great. The same attributes that result in an insect herbivore being termed a “pest” predispose it to disruption by climate change, particularly global warming. Although many pest species have co-evolved relationships with forest hosts that may or may not be harmful over the long-term, the effects on these relationships may have disastrous consequences. We consider both the data and models necessary to evaluate the impacts of climate change, as well as the assessments that have been made to date. The results indicate that all aspects of insect outbreak behavior will intensify as the climate warms. This reinforces the need for more detailed monitoring and evaluations as climatic events unfold. Luckily, we are well placed to make rapid progress, using software tools, databases, and the models that are already available.
The key statement has been underlined. It is key to this abstract, and countless others like it, as well as the runaway assumptions made by popular journalism about the topic. The statement should read this way:
The results of our examination of data and models, as well as our exploratory computer runs, indicate that if climate does warm, all aspects of insect outbreak behavior will intensify.
The conclusion of the study is actually unremarkable and rather trivial. If climate warms, bad things may happen. If it’s hotter, more people will be uncomfortable, there will be more heat stroke, ecosystems will be disturbed and will change, etc. etc. If, if, if…
Now, back to those statistics and models to figure out if the climate is actually changing as they assume it is, and to figure out why…