This story originally appeared on the Bulletin of the Atomic Scientists and is part of the Climate Desk collaboration.
There are trillions upon trillions of numbers in the world. We use numbers to describe almost every conceivable thing in the universe. But there is one number that surpasses all others for the enormous impact it will have on every living thing on Earth over the next few thousand years. We consider it so important that we’ve dedicated our lives to acquiring and understanding it. Today that number happens to be: 427.6.
This is a measure (known in scientific terms as the mole fraction) of atmospheric