How to Avoid a Climate Disaster: The Solutions We Have and the Breakthroughs We Need

by Bill Gates

Fifty-one billion is how many tons of greenhouse gases the world typically adds to the atmosphere every year. Although the figure may go up or down a bit from year to year, it’s generally increasing. This is where we are today.fn1 Zero is what we need to aim for.

To avoid a climate disaster, we have to get to zero. We need to deploy the tools we already have, like solar and wind, faster and smarter. And we need to create and roll out breakthrough technologies that can take us the rest of the way.

Tip: Whenever you see some number of tons of greenhouse gases, convert it to a percentage of 51 billion, which is the world’s current yearly total emissions (in carbon dioxide equivalents).

Tip: Remember that emissions come from five different activities, and we need solutions in all of them.

Tip: Whenever you hear “kilowatt,” think “house.” “Gigawatt,” think “city.” A hundred or more gigawatts, think “big country.”

Tip: If someone tells you that some source (wind, solar, nuclear, whatever) can supply all the energy the world needs, find out how much space will be required to produce that much energy.

Here’s a summary of all five tips: Convert tons of emissions to a percentage of 51 billion. Remember that we need to find solutions for all five activities that emissions come from: making things, plugging in, growing things, getting around, and keeping cool and warm. Kilowatt = house. Gigawatt = mid-size city. Hundreds of gigawatts = big, rich country. Consider how much space you’re going to need. Keep the Green Premiums in mind and ask whether they’re low enough for middle-income countries to pay.

To sum up, the path to zero emissions in manufacturing looks like this: Electrify every process possible. This is going to take a lot of innovation. Get that electricity from a power grid that’s been decarbonized. This also will take a lot of innovation. Use carbon capture to absorb the remaining emissions. And so will this. Use materials more efficiently. Same.

How much carbon dioxide can a tree absorb in its lifetime? It varies, but a good rule of thumb is 4 tons over the course of 40 years.