Scientists, politicians, young activists and business leaders are talking about the dire consequences of climate change. But for the average person sitting on your couch, it can be difficult to understand what is so urgent and why it is important to your life.
In his new book, “How to Avoid a Climate Disaster”, billionaire Bill Gates shares five basic concepts that helped to structure his understanding of the impending climate crisis. Gates says they can also help other people understand what is happening to Earth.
“When I started to learn about climate change, I continued to find facts that were difficult to understand,” writes Gates in the book, which comes out Tuesday. “On the one hand, the numbers were so large that they were hard to imagine … Another problem was that the data I was seeing often seemed devoid of any context.”
Gates began to develop “a mental framework” organized around five concepts. “These are complex issues that can be confusing,” writes Gates. “This structure will help you to eliminate clutter.”
Here are the buckets of information that Gates says can help you understand the importance of mitigating climate change.
51 billion tons of greenhouse gases are added to the atmosphere each year
Although emissions in 2020 were slightly less than normal due to the coronavirus pandemic that slowed travel and economic production, in a typical year, the world adds 51 billion tons of greenhouse (GHG) to the atmosphere, according to with the book.
To help put that into perspective, each of those 51 gigatonnes (one gigaton equals 1 billion tonnes) equals 2.2 trillion pounds. This is equivalent to 10,000 fully loaded American aircraft carriers, according to NASA (multiplied by 51 times).
Gates writes that when he considers any green technology or policy, he assesses its impact based on the percentage of 51 billion tons of GHG it can remove from the atmosphere.
“At Breakthrough Energy, we finance only technologies that could remove at least 500 million tons a year if they were successful and fully implemented,” writes Gates, referring to the energy innovation investment fund he has money with, along with with others like Jeff Bezos. “This is about one percent of global emissions.”
Doing things, like cement and steel, is more guilty than cars or jets
Transport and electricity often receive the most attention when it comes to addressing climate change. For example, electric vehicles are very active thanks to people like Elon Musk and his company, Tesla.
And while they are important, there is more to this story. Any comprehensive climate change strategy must consider other sources of GHG, so Gates provides an analysis of several categories and the percentage of total global greenhouse gas emissions each is responsible for:
Doing things like cement, steel and plastic: 31%
Electricity: 27%
Growing things, including plants and animals: 19%
Transport, including airplanes, trucks and cargo ships: 16%
Temperature regulation, meaning heating, cooling and cooling: 7%
5,000 gigawatts are needed to power the world
Gigawatts are a measure of energy: “If you were measuring the flow of water from the kitchen tap, you could count how many cups came out per second,” writes Gates. “Measuring power is similar, only you measure the flow of energy instead of water. Watts are equivalent to ‘cups per second’ ”, he explains.
Gates shares important measures at the bottom of the napkin to help contextualize the amount of energy needed to power various things. (One billion watts equals one gigawatt; 1 million watts equals one megawatt; and 1,000 watts equals one kilowatt.)
The world: 5,000 gigawatts
The United States: 1,000 gigawatts
Average city: 1 gigawatt
Small town: 1 megawatt
Average American family: 1 kilowatt
Some energy sources take up more space
“Some energy sources take up more space than others. This is important for the obvious reason that there is only a limit of land and water to circulate, ”writes Gates. “Space is far from being the only consideration, of course, but it is an important issue that we should talk about more often than we do.”
To measure how much space will be taken to generate a given amount of energy, scientists use a metric called power density, which is measured in watts per square meter.
It is important to consider the watts per square meter when discussing the feasibility of a specific power solution for a specific location or situation. “If you want to use wind instead of solar, you need a lot more land, keeping everything else the same,” writes Gates. “It doesn’t mean that the wind is bad and the solar is good. It just means that they have different requirements that should be part of the conversation.”
Here are the watts per square meter for some of the most commonly discussed power sources:
Fossil fuel: 500 to 10,000 watts per square meter
Nuclear: 500 to 1,000 watts per square meter
Solar: 5 to 20 watts per square meter (Gates says it is theoretically possible to reach 100 watts).
Hydroelectric power, such as dams: 5 to 50 watts per square meter
Wind: 1 to 2 watts per square meter
Wood and other biomass: less than 1 watt per square meter
It all comes down to money
“The reason the world emits so much greenhouse gas is that – as long as you ignore the long-term damage they do – our current energy technologies are generally the cheapest available,” says Gates.
Green or clean energy solutions are more expensive than using fossil fuels. Gates calls this the “green prize”. For each energy source, the green award will be different. (In very rare cases, it can be negative. For example, in some cities, installing an electric heat pump will be cheaper than having a gas furnace and air conditioning, says Gates.)
“During all the conversations I have about climate change, the Green Awards are on my mind,” writes Gates.
And since carbon emissions are a global problem, it is critical to consider what is feasible for all countries, not just those with water, says Gates.
See too:
Tesla, Elon Musk and beyond: the green companies that make billionaires
‘1%’ is driving climate change, but hits the poor harder: Oxfam report
Bill Gates: Climate change could be worse than the Covid-19 pandemic – what the US must do to prepare