The weather always gets the last laugh. It’s the rowdy guest at weddings, the unwelcome visitor at planting time, the cruel joker on the fire crew. It defeats our most dedicated efforts to plan ahead, rudely announcing that the climate is in charge. In the West, where humans habitually push the limits of the environment, droughts, heat waves and cold snaps remind us of society’s precarious perch.
But the weather isn’t what it used to be. These days, an entirely new set of factors complicates its fickle nature. Mean global temperatures rose substantially over the past century; in the Western Hemisphere, the warming was greater than in any other century of the millennium. Levels of carbon dioxide and other greenhouse gases in the atmosphere also shot upward. The degree of human influence on global temperatures is still a matter of some debate, but virtually all scientists agree that rising temperatures are real — and at least partly our doing.
Researchers are busy documenting the concrete effects of higher temperatures. Glaciers have retreated in Glacier National Park, the Sierra Nevada, and elsewhere in the world. Scientists estimate that pikas — the tiny rabbit relatives that live in high-mountain rock piles — have disappeared from nearly 30 percent of the Great Basin habitats they occupied early in the last century. There’s new and convincing evidence that our snowpack is decreasing in volume and melting earlier in the spring than ever recorded. For a region dependent on snowmelt for its water supply, this last trend may be the most sobering of all: If you think Western water politics are already too nasty and complicated, hang on tight.
Temperature is the best-documented shift in our climate, but other types of disturbances are in the offing. It’s likely that human activities are not only heating up the planet, but also changing precipitation patterns and increasing the chances of extreme weather such as floods and drought.
As these global problems land in our backyards, High Country News is watching them closely. In this issue, we look at how rising temperatures are boosting forest beetle outbreaks throughout the region, and we get the scoop on federal policy from observer Jon Margolis. Future articles will tackle other facets of our changing climate. In the vast and varied West, the weather has always been a surprisingly interesting topic of conversation; now, the talk promises to be more interesting — and more crucial — than ever.