After a year in which COVID-19 has suspended normal economic life around the world, humanity has acquired a new appreciation for risk. But simply acknowledging potential threats is merely the beginning of the process; the real challenge comes in deciding which problems warrant our attention, and in what order.
CAMBRIDGE – The reign of the dinosaurs was brought to an end 65 million years ago by an asteroid that crashed into what is now the town of Chicxulub in Mexico. Although this lump of rock and metal was not particularly large – probably about ten kilometers (six miles) across – it struck the Earth at more than 60,000 kilometers per hour (37,000 miles per hour), generating an explosion billions of times greater than that of the atomic bomb dropped on Hiroshima, and killing all life within 1,000 kilometers.
More ominously, the explosion sent a massive cloud of dust and ash into the upper atmosphere, blocking the sun for years to come. This prevented photosynthesis and led to sharply reduced temperatures, which is why scientists reckon that it was this atmospheric dust and sulfate aerosols that ultimately killed the dinosaurs and many other species.
If a similar asteroid or comet were to crash into Earth today, it would cause another mass-extinction event, wiping out most species and human civilization as we know it. This distant possibility is an example of a natural existential risk: an event not caused by humans that leads to the extinction or near-extinction of our species.
CAMBRIDGE – The reign of the dinosaurs was brought to an end 65 million years ago by an asteroid that crashed into what is now the town of Chicxulub in Mexico. Although this lump of rock and metal was not particularly large – probably about ten kilometers (six miles) across – it struck the Earth at more than 60,000 kilometers per hour (37,000 miles per hour), generating an explosion billions of times greater than that of the atomic bomb dropped on Hiroshima, and killing all life within 1,000 kilometers.
More ominously, the explosion sent a massive cloud of dust and ash into the upper atmosphere, blocking the sun for years to come. This prevented photosynthesis and led to sharply reduced temperatures, which is why scientists reckon that it was this atmospheric dust and sulfate aerosols that ultimately killed the dinosaurs and many other species.
If a similar asteroid or comet were to crash into Earth today, it would cause another mass-extinction event, wiping out most species and human civilization as we know it. This distant possibility is an example of a natural existential risk: an event not caused by humans that leads to the extinction or near-extinction of our species.