Around the world we humans are adding an average of fifty-one billion (51,000,000,000) tons of greenhouse gasses to Earth’s atmosphere every year.

To avoid a climate disaster, we need to get to zero. 51 billion to zero.

That’s how Microsoft co-founder and philanthropist Bill Gates opens his new book How to Avoid a Climate Disaster: The Solutions We Have and the Breakthroughs We Need.

How to Avoid a Climate Disaster is the clearest and most straightforward explanation of the climate crisis I’ve ever read. Gates lays out the enormous and unparalleled challenges we face. Yet he’s optimistic about our chances of success and he presents ambitious yet plausible proposals for how to solve the problem.

How to Avoid a Climate Disaster
By Bill Gates
Alfred A. Knopf, New York, 2021

Before I go any further, a disclosure: I used to work at Microsoft.

I think the most important idea in this book is the “Green Premium.”  The Green Premium represents how much more you have to pay if you switch from today’s conventional carbon-emitting products to a zero-carbon alternative. For example, today electric vehicles (EVs) cost several thousand dollars more than comparable fossil fuel powered cars. That’s the Green Premium. The good news is that the Green Premium for cars is coming down fast. Gates predicts that within a few years it will actually be negative – EV’s will be cheaper than gasoline powered cars.

For other products the Green Premium is extremely high because we don’t yet have practical climate friendly alternatives. Take cement. Today there’s just no way to eliminate the carbon that’s produced when we make it. There’s no such thing as “green cement.” The best we can do is try to capture and store the carbon that’s released when cement is made. But as Gates points out, carbon capture is expensive. Adding the cost of carbon capture to the price of cement results in a very large Green Premium; cement so expensive no one will buy it.

To get from 51 billion to zero, Gates says we need to drive Green Premiums down below zero for basically everything so that people and organizations have available and affordable green alternatives.

OK, how?

Like a good software engineer, Gates breaks the problem down into smaller chunks and then attacks each chunk one at a time. He divides the 51 billion tons of greenhouse gas emissions into five slices shown in this pie chart.

Source: How to Avoid A Climate Disaster, p. 55

He devotes a chapter to each slice, looking at what we’re doing today, what zero-carbon alternatives already exist, and what innovations we need to deliver solutions that don’t yet exist, like green cement.

From reading the book, I’d say the most important slice of the 51 billion comes from “how we plug in,” how we generate electricity. Partly that’s because it’s one of the largest slices. But it’s also because many of the methods for reducing greenhouse gas emissions in the other slices rely on electrification. For example, instead of using heating oil or natural gas to heat and cool our homes and heat our water, Gates recommends switching to heat pumps. Heat pumps run on electricity. But if that electricity is generated from natural gas, or worse yet, coal, then there’s not much benefit from switching.

Generating clean energy not only reduces carbon emissions from “how we plug in,” it’s part of the solution to most of the other slices too. Generating clean energy cheaply will help reduce the Green Premium of everything that uses electricity.

Innovation is the primary way to reduce the Green Premium, but Gates suggests we can also make traditional products more expensive by putting a price on carbon emissions (either a carbon tax or a cap-and-trade system) and by stricter regulations. He has plenty of suggestions for both approaches throughout the book.

Gates acknowledges he’s an “imperfect messenger” on climate change. He doesn’t deny being a “rich guy with an opinion” who owns big houses and flies around in private jets. But, as he points out, his opinions are well informed, and he keeps learning more. He also says he’s taking steps to reducing his family’s carbon footprint.

Gates is a technophile, and the main focus of the book is unapologetically about technological approaches to climate change. Yet he doesn’t ignore the social and political aspects of the problem. The last couple of chapters suggest actions that governments can take and that we as individuals can take. His philanthropic work on global health has made him keenly aware of the impacts of climate change on some of the world’s poorest countries. He’s very clear about the responsibility that rich countries have in helping poorer ones adapt to climate change,

That said, if you’re looking for an in depth analysis of how economic, racial and other social justice issues intersect with climate change — an important topic for sure — be aware that’s not what Gates is writing about in this book.

Gates also does not discuss ecosystem restoration approaches such as rewilding that could repair the Earth’s capacity to absorb and retain carbon.

Nonetheless, I think everyone should read How to Avoid a Climate Disaster. Literally everyone: you, your partner, your kids, your in-laws, your city council, and most definitely your provincial, state and national legislators.

How to Avoid a Climate Disaster describes the daunting challenges we face in clear and simple terms. It also presents a hopeful roadmap that shows how we can preserve our planet for future generations.