U.S. Special Presidential Envoy for Climate John Kerry caused a stir over the weekend, telling the BBC that half of carbon emissions cuts in the coming decades will come from technologies “we don’t yet have.”

Kerry’s statement reignited a longstanding debate among climate hawks: Can we rely on tried-and-true technologies alone to meet emissions targets? How far can today’s solar panels, wind turbines, batteries, electric vehicles, and electric heat pumps get us without other technologies that have yet to prove themselves at scale?

Now a new report by the International Energy Agency, or IEA, has added new data to the fray. For the first time ever, the IEA modeled what it would take for the world to achieve a net-zero emissions energy system by 2050 and still have a 50 percent chance of limiting global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit).

The IEA’s road map, which was released Tuesday, includes an unprecedented deployment of existing technologies over the next decade: Renewable energy and electric vehicles would be scaled up faster and more extensively than they have been in many previous net-zero models.

In this version of the future, the sale of new gas-powered cars ends everywhere in the world by 2035. Ninety percent of global electricity generation comes from renewable sources by 2050. Our cars and buildings and industrial processes become so efficient—thanks to lighter materials, energy-saving appliances, and innovations like waste heat recovery—that, by 2050, the global economy will be 40 percent larger than it is today, but use 7 percent less energy.

Read the full article about going net-zero by 2050 by Emily Pontecorvo at Grist.