Back in March, you may have recalled reading headlines in which Senator Jim Inhofe, A republican congressman from Oklahoma, and chairman of the Environment and Public Works Committee, brought in a snowball from outside of the Capitol building famously saying “We keep hearing that 2014 is the warmest year on record… do you know what this is? It’s a snowball, from outside here, and it’s very very cold out” Although the DC area may have experienced a higher amount of snowfall this year, the same cannot be said of the rest of the country; The Sierra Nevada’s snowpack levels are the lowest they’ve been in over 500 years.
In a recent study published by Troet et. al. in the September issue of Nature Climate Change magazine, climate scientists cite a variety of evidence showing that the snowpack levels in the Sierra Nevada are critically low. This news comes after the driest summer on record in California, accompanied by a 3-year-long drought. The timing of this drought and these record low snowpacks are not random; they are the direct result of human impact on the environment, and in order to stop a global ecological catastrophe from happening we need to seriously reduce are carbon output and water usage.
According to the paper published this week, record collections over the past 50 years show that snow pack levels are only 5% of the 50 year historical average. Additionally, the snow pack levels have never been this low, although yearly fluctuations do exist. So how then does our knowledge of the California drought extend so far back in time when the earliest meteorological data dates back to the turn of the century?
Scientist used the tree ring patterns from some 1500 blue oak trunks from 33 sites in the California Sierra Nevada chain. Matching meteorological data for the past 50 years up with tree rings showed that in the wettest years, the tree rings were the widest, and that in the driest years, the tree rings were narrowest. The scientists then created a model in which they could predict past precipitation, extending to the year 1500, using the blue oak tree ring width as a marker. Analysis of the rings showed conclusively that snowpacks are at their lowest in 500 years. This surprising data makes sense given the larger context of the drought in California; one-third of the state’s water usage comes from the snowmelts on the Sierra Nevada slopes.
Without the winter precipitation the Sierra Nevada slopes usually sustain, California’s ability to withstand the dry months of its Mediterranean climate are greatly diminished. This is especially hard news after wild fires are spreading across the state; just this past weekend nearly 600 homes have been destroyed, with an additional 9,000 threatened. In total, over 24,000 people have been displaced, and over 133,000 acres of pristine ecosystem featuring some of the world’s oldest and tallest trees have been damaged or destroyed by wildfires that still have a long way to go to being totally contained. It is likely that only much needed winter precipitation will see an end to this dry season.
According to Valerie Trouet, a climatologist at the University of Arizona who specializes in reconstructing climate data from the past, and one of the authors of the study, “the 2015 snowpack in the Sierra Nevada is unprecedented”, adding “we expected it to be bad, but we certainly didn’t expect it to be the worst in the past 500 years”. The situation in the Sierra Nevada is just one of the growing pieces of evidence of human impact on the environment; the precipitation is at its lowest since Colombus arrived on the continent.
While Republicans in Congress and climate-deniers everywhere remain convinced that our climate and weather patterns are independent of human influence, or even that there is no climate change happening at all in the wonderful case of Senator Jim Inhofe and the snowball, I argue that the latest data is warning call to everyone who cares about the environment, regardless of their explanation for its change. In the words of John Muir: “God has cared for these trees, saved them from drought, disease, avalanches, and a thousand tempests and floods. But he cannot save them from fools.”
Trouet, Valerie, Soumaya Belmecheri, Flurin Babst, Eugene R. Wahl, and David W. Stahle. “Multi-century Evaluation of Sierra Nevada Snowpack.” Nature Climate Change (2015): 1-2. Nature Online. Nature, 14 Sept. 2015. Web. 15 Sept. 2015.
All photos used were my own.