There's a running joke in Pemberton that after being beset by fire and flood from the 2009 spate of forest fires and the 2010 Meager Creek landslide evacuations, we'll surely next be hit by a plague of locusts or a famine. We all laugh, but it isn't really funny. Along with these "everyday" disasters, there are far, far more serious threats that we should all be prepared for.
Imagine waiting for months as a kilometre-wide chunk of rock comes hurtling towards the Earth, holing up in your home as day turns to night, and scrabbling for food as the world's crops die. Or having only minutes of warning before a solar storm fritzes out the power grids around the world, taking out communication satellites and plunging us into the dark and cold. The collision of distant stars could, at any moment, fire a beam of high-energy radiation at our planet that would fry sea life at the base of our food chain. And if hazards from outer-space weren't enough to worry about, there are equal dangers lurking underfoot. Supervolcanoes under the bubbling vents of Yellowstone national park and other sulphuric sites hold the potential to erupt so massively that they coat a continent in centimetres of ash, sending us into a nuclear winter. The Pacific Northwest is by some counts overdue for a megaquake. And don't forget disease. Pandemic flu is expected to cull large swaths of the population, and fungi are evolving to take out our most important food crops.
These disasters might sound the stuff of Hollywood fiction. But they have all happened to the Earth before, and are all guaranteed to happen again. It's just a question of when.
Fortunately, people in the Sea to Sky have a higher-than-average supply of survival knowledge, access to good farmland in Pemberton and seafood in Howe Sound, plenty of wood to burn and rivers to tap for water and energy. Of all the places in the world to have to hole up to ride out a disaster, this isn't bad. But are we really ready for what the Universe might have in store?
Just this February, a 45-metre wide, 130,000 tonne asteroid squeaked by within 27,000 km of Earth — less than one tenth of the distance to the Moon, and a hair's breadth in terms of the vastness of space. Flybys like this are thought to happen about once every 40 years, with a collision every 1,200 years or so. Astronomers watching this particular incoming missile, called 2012 DA14, knew for a year in advance that it would miss us — but we are sure to run out of luck eventually.
Such collisions can be fatal on a planetary scale. Most famously, the dinosaurs' reign on Earth was brought to an end 65 million years ago when a 10-km wide chunk of rock hit the planet. Smaller, still-deadly collisions are far more common: NASA expects a two-kilometre wide rock, large enough to cause local extinctions, to hit us once or twice every million years. A tiny taste of what such collisions might be like was seen, coincidentally, also in February of this year, when a 17-metre wide meteor burned through the atmosphere and exploded over Russia, creating a shock wave that blew out glass from thousands of buildings and left a thousand people in need of medical care. That rock was too small for anyone to see it coming — it struck literally without warning. The last time something like that happened was in 1908, when a 60-metre rock exploded above Siberia, flattening 80 million trees over 2,000 square-kilometres. Incidents like this are expected every hundred years or so, and could take out a city 15 times as large as Vancouver.