There are, we are told, only two options: Either we stop burning fossil fuels before our carbon dioxide emissions drive the planet's average temperature up a full 2 degrees Celsius, in which case we will push the world into the biggest-ever recession. Or we continue to burn fossil fuels and push the planet into runaway warming, with lethal consequences for a large part of the human race.
The 2008 bank crash that triggered the recent recession was caused mainly by reckless investment that created a "bubble" in housing prices. When the bubble burst, hundreds of billions of dollars' worth of investments suddenly became worthless. The losses were so great that they nearly brought the whole banking system down.
This time the problem is a "carbon bubble."