In a column equating those concerned about climate change with members of a “doomsday cult,” the Wall Street Journal's James Taranto quoted the following two headlines in an apparent effort to bolster his claim that global warming is not “real science” :
- “Decline in Snowpack Blamed on Warming” --headline, Washington Post, Feb. 1, 2008
- “Record Snowpacks Could Threaten Western States” --headline, New York Times, May 22, 2011
Taranto suggests that this year's record snowpacks in western states undermine previous research indicating that global warming is pushing down snowpack levels. But, as is often the case with conservative media seeking to downplay the threat of climate change, Taranto relies on the misconception that short-term data can invalidate a long-term trend.
The first article he references, from the Washington Post in February 2008, reports on a study which concluded that a significant portion of the decline in snowpack in the western U.S. between 1950 and 1999 was a result of human-induced climate changes. According to the authors of that study, Taranto is making a fundamental mistake in suggesting that this year's snowpack levels contradict their findings.
Tim Barnett, research marine physicist at the Scripps Institution of Oceanography said Taranto is comparing “apples and oranges” and that “the difference between year to year changes in the weather and long term changes in climate are not really comparable.” Barnett's co-author David Pierce similarly explained that “confusing the year-to-year up and downs with the long-term decline is a fairly common mistake that people make” and “shows a sad ignorance of climate science.” He added:
We can have both natural fluctuations such as El Nino and La Nina, which cycle back and forth over the years, and slow, long-term warming due to human effects on climate. Having humans affect the climate doesn't suddenly stop the effect of natural fluctuations such as La Nina.
Benjamin Santer, a research scientist at the Lawrence Livermore National Laboratory and also a co-author of the 2008 study said “Mr. Taranto is woefully ignorant of the basic concepts of 'signal' and 'noise'. Year-to-year climate variability does not constitute 'evidence of absence' of a human effect on climate, as Mr. Taranto mistakenly believes.”
Indeed, as the University of Washington's Department of Atmospheric Science explained in 2007, snowpack
will continue to be affected by large year-to-year and decadal changes in weather and associated temperature and precipitation amounts. These year-to-year variations will continue to be larger than the year-to-year changes associated with global warming for several decades, but we expect that the effect of global warming will be more systematic and persistent and will increase over time.
Snowpack is considered an important area of climate change research because “snowpack runoff is critical to the water resources in the western United States” and “changes in the timing and amount of runoff can exacerbate problems with already limited water supplies in the region,” according to a 2009 report commissioned by Congress and issued by the U.S. Global Change Research Program. The report further stated:
Large portions of the West and some areas in the Northeast rely on snowpack as a natural reservoir to hold winter precipitation until it later runs off as streamflow in spring, summer, and fall. Over the last 50 years, there have been widespread temperature related reductions in snowpack in the West, with the largest reductions occurring in lower elevation mountains in the Northwest and California where snowfall occurs at temperatures close to the freezing point. The Northeast has also experienced snowpack reductions during a similar period. Observations indicate a transition to more rain and less snow in both the West and Northeast in the last 50 years. Runoff in snowmelt-dominated areas is occurring up to 20 days earlier in the West and up to 14 days earlier in the Northeast.
The Intergovernmental Panel on Climate Change similarly said in its Fourth Assessment Report that “Mountain snow can be sensitive to small changes in temperature, particularly in temperate climatic zones where the transition from rain to snow is generally closely associated with the altitude of the freezing level.” The IPCC also noted that “Mountain snow water equivalent [a measure of how much water is stored in snowpack] has declined since 1950 at 75% of the stations monitored in western North America."
As Pierce and Barnett show in the following charts, snowpack (measured at the beginning of April) has generally fallen in many western U.S. regions over the past half-century, despite significant year-to-year variations:
According to the National Research Council, “Snow is expected to melt even earlier under projections of future climate change,” which has “major implications for ecosystems, hydropower, urban and agricultural water supplies, and other uses” :
Another robust projection of climate change is that snow and ice cover should decrease as temperatures rise. Worldwide, snow cover is decreasing, although substantial regional variability exists. In the United States, changes in snowpack in the West currently represent the best documented hydrological manifestation of climate change.
The largest losses in snowpack are occurring in the lower elevations of mountains in the Northwest and California, as higher temperatures cause more precipitation to fall as rain rather than snow. Moreover, snowpack is melting as much as 20 days earlier in many areas of the West. Snow is expected to melt even earlier under projections of future climate change, resulting in streams that have reduced flow and higher temperatures in late summer. Such changes have major implications for ecosystems, hydropower, urban and agricultural water supplies, and other uses.
In his column, Taranto professes concern about a “corruption of science,” but his cursory and misleading treatment of snowpack research indicates that he's not very much interested in the science at all.