Published in: 2021
In this book, Bill Gates tries to decipher the complex connections to explain what research says about the climate issue. Greenhouse gas emissions have increased dramatically since the 1850s due to human activities, such as the burning of fossil fuels. We have already raised the temperature by at least 1 degree celsius since the industrial age, and if we do not reduce emissions, it will probably be between 1.5 and 3 degrees warmer in 2050 and between 4 and 8 degrees warmer by 2100. This book is about what it takes to stop this and why we can do it.
FROM 51 BILLION TO ZERO. 51 billion is the number of tonnes of greenhouse gases that the world emits into the atmosphere on average each year. The figure may vary slightly from year to year, but in general it is increasing. Zero is what we must strive for. To stop warming and avoid the worst effects of climate change – and they become very unpleasant – we must stop releasing greenhouse gases into the atmosphere. To avoid a climate catastrophe, we must (1) bring down emissions to zero, (2) use all the resources we have – such as sun and wind – in a faster and smarter way, and (3) we must develop and apply all technological breakthroughs that can take us the rest of the way.
WHY ZERO. Because the greenhouse gases stay in the atmosphere for so long, the planet stays warm long after we have reached zero. About one-fifth of the carbon dioxide emitted today remains in 10,000 years. There is no scenario where the world stops getting warmer if we continue to increase the carbon dioxide in the atmosphere, and the hotter it gets, the harder it will be for humans to survive – even less feel good. We do not know exactly how much damage will be caused by a certain temperature rise, but we have every reason to worry.
HOW MUCH GREENHOUSE GAS IS RELEASED BY CATEGORY. Manufacturing (cement, steel, plastic) accounts for 31% of emissions. Energy production accounts for 27%. Agriculture / cultivation (plants and animals) accounts for 19%. Transport (aircraft, trucks, cargo ships) accounts for 16%. Heating and cooling account for 7%. Some things, like electricity and cars, get a lot of attention. Passenger cars account for 47% of all emissions from the transport sector (garbage trucks, buses and trucks 30%, cargo cruise ships 10%, aircraft 10% and the other 3%), which in turn is 16% of the world’s total emissions. These are important, but improvement needs to happen everywhere.
A BALANCING ACT. The world is emitting less greenhouse gases this year  than last year because economic activity has slowed down so sharply due to Covid-19. The decline in 2020 will probably be somewhere around 5%. In real terms, this means that we emit between 48 and 49 billion tonnes of greenhouse gases instead of 51 billion. This small decrease in emissions proves that we cannot reach zero simply by not flying and driving as much as before. We have with Covid now seen the high societal cost – deaths, unemployment, mental health, etc – of putting the world on paus. In addition, there is the perspective that the world must produce more energy so that the poorest can get better. We must produce energy without emitting more greenhouse gases – it must be clean energy.
POPULATION GROWTH. The world’s population is approaching 10 billion at the end of the century. By 2060, the world’s building stock has doubled. It’s like building a new New York every month for 40 years, and that’s mainly due to the growth in developing countries like China, India and Nigeria. What happens when more people live as the richest 16 percent do today? Global energy demand will have risen by 50 percent by 2050, and if nothing else changes, emissions will rise almost as much. It will not be easy to get electricity from all over the world from clean sources. Today, fossil fuels account for two-thirds of all electricity generated worldwide (Coal 36%, natural gas 23%, hydropower 16%, nuclear power 10%, renewable 11%, oil 3% and other 1%). Today, the United States spends only 2% of its GDP on electricity. The main reason is that fossil fuels are cheap.
ELECTRICITY AND DENSITY. As the numbers get high quickly, it is convenient to use abbreviations. One kilowatt is 1,000 watts, one megawatt is 1 million and one gigawatt is 1 billion. In the world, 3,000 gigawatts are consumed, in the United States 500 gigawatts, in a medium-sized American city 1 gigawatt, in a small town 1 megawatt and in an average American home 1 kilowatt. An important factor is energy density. Different energy sources can generate different amounts per square meter: fossil fuels (500-10,000 watts per square meter), nuclear power (500-1000), solar energy (5-20), hydropower – dams (5-50), wind (1-2) and firewood and other biomass (less than 1).
ENERGY TRANSITION TAKES TIME. The wind does not always blow, and the sun does not always shine, and we do not have cheap batteries that can store energy long enough for large cities. Many have heard of Moore’s law, Gordon Moore’s prediction in 1965 that the capacity of microprocessors would double every two years. He was right. But computer chips are something in themselves. The solar panels, for example, have not become a million times better. When crystalline silicone solar cells were introduced in the 1970s, they converted c.15% of sunlight into electricity. Today, they convert c.25%. It’s good but far from Moore’s team.
ENERGY STORAGE. Solar power costs about 5 cents per kilowatt hour. The price for the electricity from this if we were to store overnight is three times higher than what we pay during the day: 5 cents to generate and 10 cents to store, a total of 15 cents. There are researchers who believe they can manufacture a battery with 5x longer life. They have not done so yet, but if they are right, it would push down the extra cost from 10 to 2 cents. Nothing can be more important than taking advantage of today’s renewable energy sources and improving transmission.
LITHIUM BATTERIES. Lithium-ion batteries – despite their limitations – are the best we can hope for. Researchers have studied all the metals that we could use in batteries, and it seems unlikely that there are materials that could provide better batteries than the ones we already design. Gates thinks we can improve them by a factor of 3x but not by a factor of 50x. The larger the vehicle to be moved and the longer it is to be driven without charging, the more difficult it will be to have electricity as an energy source. Unless an unlikely breakthrough occurs, batteries will never be so light and powerful that they can move aircraft and ships more than short distances. In addition, the production of electricity accounts for only 27% of all emissions. Even if we had a huge breakthrough in batteries, we would still have to get rid of the other 73%.
ELECTRIC VEHICLES – THE POSTER CHILD. The price difference between electric cars and petrol-powered cars has shrunk dramatically in recent years. This is largely due to the fact that batteries have become much cheaper – a reduction of 87% since 2010 – and also to various tax breaks and government measures to ensure that there are more emission-free cars on the roads. In some countries in Europe, petrol prices are so high that the green additional cost of electric cars has already come down to zero. As battery prices continue to fall, Gates predict that the additional cost of most cars in the US will also be zero by 2030. With so many electric buses sold In China, Gates believes that the green additional cost of buses will be reduced to zero within 10 years, which means that most major cities in the world can switch to electricity.
THE COST MAKES INVESTMENTS WORTH IT. Recent models show that the cost of climate change in 2030 is likely to be between 0.85 and 1.5 percent of US GDP per year. Current estimates of the cost of Covid-19 in the United States this year vary between 7-10 percent of GDP. Assuming a similar disturbance occurs once every ten years, it means an average annual cost of 0.7 to 1 percent of GDP, roughly equivalent to the damage that climate change is expected to cause.