Watt's your problem?

Sometimes people ask me why global warming focuses on CO2 instead of heat. When I burn gasoline, doesn’t it produce heat? Isn’t heat responsible for global warming?

When you drive your car, fuel gets burned and a lot of heat is produced. In order to keep your engine cool, this heat gets sent through the radiator, where it gets released into the atmosphere. This warms the air around your car and keeps your car cool.

Despite this, the amount of heat released into the atmosphere while driving is very small when compared to the amount of heat trapped by carbon dioxide. Let’s look at some numbers to make sure.

World-wide, we are using somewhere around 6 x10^12 (6 million million) watts of energy at any point in time. That’s a whole lot of light bulbs. Since burning fuel usually makes more heat than useful energy (about 3 times as much), we’ll estimate that 18 million million watts of heat are being produced at a time. Yikes!

Now let’s compare that to the amount of heat being trapped by greenhouse gases. According to the most recent IPCC report, the atmosphere captures 1.6 watts/square meter more heat than it did before the industrial revolution. That means for every square meter of space on our planet, 1.6 extra watts of sunlight are warming the atmosphere. How much heat does that produce? Well,

1.6 watts/sq meter x 510 trillion square meters on our planet =
816 million million watts of heat trapped by greenhouse gases

That’s a whole lot more than we calculated for burning fuels.

Maybe heat produced by a car engine or a power plant is enough to warm the earth, but I am pretty sure that greenhouse gases are responsible for our hyper-speed climate change. At this very moment, greenhouse gases are warming our planet 45 times more than the burning of fuels.