I want to return to a good reminder piece that appeared last year in the New York Times on the ongoing drought crisis in California:
Easier to forget is that we consider the last 150 years or so to be normal, but you don’t have to go back very far at all to find much drier decades, and much drier centuries
Human memory is limited to the scale of generations, around 60 years more or less. We tend to forget, misjudge, or ignore the past because of the immense scales of time – and the scale of drought among them – that escape our present-based thinking. The article continues:
Within that century and a half of relative wetness, the period from the mid-1970s to the late 1990s – a time when California’s population soared by 50 percent – was even wetter, said Dr. Seager of Lamont-Doherty. ‘All of that growth occurred at a time when more water was available than you’d expect’
The clouds rolled in from the Pacific this past rainy season. In the lowland hills and valleys they brought the rains so vital to the 54 billion USD (as of 2014) agriculture sector in the state. Snows fell when the storms rose through the peaks of the Sierra Nevada. The snow-pack, whose melt provides irrigation water for the agriculture industry, approached historical averages, according to a NASA survey in March of 2016.
Mention of the drought has left the attention of the media. The threat of drough, however, does not leave. Its most insidious aspect is its lethargy. Drought moves slow: the rains decrease; the snow grows thinner; flowers and grasses dry out while the trees endure until even they succumb to thirst. Months go by as these changes unfold, unnoticed by public authority and private citizen alike until communities run out of water and need daily shipments of bottled water.
The rhythms of nature unfold on larger time-scales than the 24 hour news cycle. As a part of the natural world, drought is always-returning. In pre-Industrial eras times of rain preceded times of drought, and days of drought days of rain. With the creep of anthropogenic climate change these cycles shift. Drought grows more intense, less rain falls in fewer months, and communities spiral into crisis. In response to this threat, we search for new sources of water: We dig deeper wells, distill potable water from the ocean, practice an ethic of conservation. In any event, drought does not wait for us.