In a typical year, humans are releasing approximately 51 billion tons of carbon dioxide and other greenhouse gases into the atmosphere; this figure is based on data from 2022. It’s tricky to imagine what a billion tons of anything looks like, but to give you a sense of scale, this is equivalent to about 8,500 Great Pyramids of Giza or 150,000 Empire State Buildings. However, carbon dioxide is a lot more airy than your average Egyptian pyramid, so our emissions take up quite a bit more space every year. That massive gas amounts to about 26 quadrillion liters, enough to fill up the Grand Canyon six times over.
The carbon dioxide we’re pumping into the atmosphere is causing unprecedented climate change, but why do we release so much carbon into the atmosphere and how easy will it be to change our ways?
Hi, I’m M Jackson and this is Crash Course Climate Energy. In the latter half of the 18th century, Scottish engineer James Watt made some improvements to the design of a coal-powered steam engine. He hoped that his new engine would make it more efficient to pump water out of the bottom of deep coal mines, but it ended up doing a lot more than that. Watt developed the first modern steam engine and it set us on the course for the Industrial Revolution.
After a couple hundred thousand years of doing things by hand or with animals, in just a few decades we switched to doing pretty much everything with the help of machines. This transition ultimately relied on energy-rich fuels, specifically coal, oil, and natural gas. These collectively are known as fossil fuels because they form much like fossils do.
The story of fossil fuels goes like this: once upon a time, some plants or algae died, as they tend to, but instead of decaying away, their carbon-rich bodies were trapped inside sediments that later became rock. Then over millions of years, those rocks were heated and squeezed by geologic processes, transforming the remnants of those plants and algae into huge unrecognizable reservoirs of carbon-rich material – imagine a disgusting underground soup.
And today, when you fire up your gas stove for mac and cheese or hop on a bus, some of that prehistoric material is burned to power your life. Take that in for a second: on a daily basis, you’re interacting with matter that’s older than dinosaurs! You’re just the latest in a long line of humans to tap into these reserves.
We’ve been using fossil carbon as a fuel source since as early as Roman times, when coal was used to heat public baths. That’s because fossil fuels are much more energy dense than the alternatives, meaning they pack a lot more bang for their buck than things like wood or charcoal.
Around the mid-1700s, when engineers figured out how to use all that bang to make our lives easier, things got really interesting. The key was to transform the chemical energy tied up in fossil fuels into mechanical energy that could physically move and power machines. For example, engines do this by burning fuel to turn chemical energy into heat energy. That heat energy is then used to boil water and make steam, which is trapped in a pressurized container. But as that steam is released, it has the power to push a piston or turn a turbine, creating movement that can power a pump, a wheel, or the entire Industrial Revolution.
That new technology transformed manufacturing, agriculture, and transportation, making it all faster and more efficient, fundamentally reshaping the way we live, work, and play. And now these fuels are everywhere: coal is burned in power plants, diesel runs trucks and trains, natural gas heats homes and businesses, and fossil fuels are even processed to make plastic used in everything from your toothbrush to your smartphone.
After seeing how powerful these fuels could be, governments made policies to encourage their use and keep them affordable. But this 260-year love affair with fossilized carbon has come at great cost: burning these fuels releases carbon dioxide into the atmosphere, and over time, that gas is built up, now helping to trap heat close to Earth’s surface via the greenhouse effect, causing the planet to warm and the climate to change at an unprecedented rate.
If we want to slow that rate and reduce our emissions, it’s going to take a lot of effort and a big shift in the way we think about energy.