Study: our Paris carbon budget may be 40% smaller than thought | Dana Nuccitelli

How we define "pre-industrial" is important

In the Paris climate treaty, nearly every world country agreed to try and limit global warming to no more than 2C above pre-industrial temperatures, and preferably closer to 1.5C. But a new study published in Nature Climate Change notes that the agreement didn't define when "pre-industrial" begins.

Our instrumental measurements of the Earth's average surface temperature begin in the late-1800s, but the Industrial Revolution began in the mid-1700s. There's also a theory that human agriculture has been influencing the global climate for thousands of years, but the mass burning of fossil fuels kicked the human influence into high gear.