Time for a science-tastic, carboniferous Episode Extra™ to accompany my latest YouTube vid!
In the most recent episode of It’s Okay To Be Smart on YouTube, about how we all share the same air, the #1 question from People Who Are Watching was about a number I mentioned in the beginning: We hoomanz are emitting 33-34 billion tons of CO2 a year. If the atmosphere is so dang big, is that amount of CO2 a lot?
A few people were subsequently all “Wait a sec, is Joe referencing climate change here?! Rabble rabble rabble!!!” Congrats. You caught me. Guilty as charged. But there’s science on my side, and you know what they say about science:
Where the carbon comes from: the primary people-caused CO2 sources are fossil fuels, deforestation, and cement production. Since 1850, over one thousand billion (AKA “a trillion”) tons of CO2 have been added to the atmosphere. We put about 34 billion tons of CO2 into atmosphere in 2011, the latest year I could find data. These are not debatable facts, minus a few decimals of statistical error. We can measure them, we have the technology.
Where does it go? Only 55% of this is removed by the oceans (dissolved CO2 and photosynthetic organisms) and the plants in our jungles and forests. Fifty years ago, as much as 60% of that CO2 would have been removed by oceans and plants. That means that not only are we increasing the amount of CO2 we emit every year, but plants and oceans (the carbon “sinks”) can’t keep up with the rate that we are adding it to the atmosphere.
Sure, as more carbon is put into atmosphere, plants and plankton can reproduce and take more of it up. But if we pump it out faster than they proliferate, it’s still a net loss. Oceans might actually be less able to absorb CO2 as the world warms (it’s simple chemistry, think about warm carbonated soda).
Then we get to the warming part. CO2 makes up less than one tenth of one percent of Earth’s atmosphere. So it can’t be that big of a deal to increase that by like 0.01% right? Wrong. Sure, for every million molecules of air, only ~391 of them will be CO2, but carbon dioxide is an amazingly powerful molecular mirror for solar energy, reflecting it back down to Earth and heating our planet. The math is complex, but tenths of tenths of percent changes in CO2 concentrations can lead to full degree changes in global temperatures. This doesn’t even include the effects of methane, which is almost 1,000 times less abundant as CO2, but contributes a whopping 1/5th of greenhouse gas effects.
For more: A paper in PNAS about carbon emissions and carbon sinks. A summary of emissions, warming and greenhouse gases from NOAA. Finally, you might need this: How to talk to a climate skeptic.