It’s been three weeks since the Deepwater Horizon explosion killed 11 crew members, injured seven others, and began the release of an estimated 5,000 barrels of oil per day into the Gulf of Mexico, just south of Louisiana. Give it another month, and this spill will reach the magnitude of the Exxon Valdez. This will leave it far short of the biggest oil spills in history (it’s the smallest spill in the chart below).
But the gross volume of oil, whether measured in barrels or gallons, is not the only measure of a disaster’s impact. It’s much more complex than that. We’ll want to know how much ecological damage this spill has done, compared to other spills, and this will depend on environmental conditions and the environments affected. Ecological damage can be hard to measure. Are we looking at acres affected? Ecosystem function disrupted? Numbers of wildlife killed? Or more anthropocentric measures like people killed, damage / clean up costs?
Now compare this spill with the eruption of Mount St. Helens almost thirty years ago, which killed 57 people and denuded 230 square miles of coniferous forest. It was a devastating blast, yet we think of it very differently than we will the Horizon spill in thirty years. Partly this is because the effects of the oil spill are and will be less visible. Partly it’s because the obvious effects will have dissipated; there won’t be a visible blast zone. But much of the difference will be because one disturbance was “natural” and the other was human-caused. We celebrate the power of nature. We lament the power of humans.
But the most salient reason for thinking of these two disturbances differently is that Mount St. Helens represents a class of discrete events from which natural systems have routinely recovered. The Horizon spill arises from our 150-year experiment with fossil fuels, which has begun to have cumulative effects that we’ve been warned about for decades.
The most serious threat, of course, is climate disruption. Far more serious than the effects of all prospective twenty-first century volcanoes and earthquakes. Far more serious than all past and future oil spills. Yet, what grabs headlines? Volcanoes, earthquakes and oil spills. Why? Two reasons. Firstly, we can see these disasters, and their effects. They’re easy to put on the nightly news in a way that climate disruption isn’t. Secondly, they’re more tractable – they’re discrete in time and space. They’ll go away. Then we can forget about them.
Climate disruption, by contrast, isn’t going away, but it’s not quite “here to stay” either. It’s worse than that. We don’t know for sure what it will look like in fifty or one-hundred years. Only that it will probably look worse than it does now. Bummer. So the easy response is to go on about our lives. To forget. Remembering disasters, natural and human-made, like the 1980 eruption of Mount St. Helens, and the 1989 Exxon Valdez, and the 2010 Horizon Deepwater, is important. Why? Because we need the practice.