Some actual numbers. (Engineers like things quantified.)

Atmospheric CO2 was identified as a greenhouse gas over 100 years ago. We’ve been measuring it ever since. Technology has allowed us to measure atmospheric CO2 over ever longer time scales. Polar ice cores contain tiny air bubbles that allow us to measure atmospheric CO2 over much longer time periods. We have a clear picture of what the atmosphere has been like over the past several hundred thousand years, and longer. It’s been over 40 years since Hansen made his forecasts before Congress on what would happen in the future with respect to CO2 and climate change, and it’s all come true, and it continues to get worse. Atmospheric CO2 is now at the highest level it’s been for over a million years.

Yet, there are many people who believe that climate change is a hoax. A favorite meme that I see is that volcanoes put more CO2 into the atmosphere than humans. I was listening live when that rumor began.

In the early 90s, I enjoyed listening to Rush Limbaugh. I enjoyed his style of pretending to be highly educated and ridiculing politicians and social movements. I was listening on the day he began his long stretch of daily comments about the eruption of Mt. Pinatubo, in the Philippines. He claimed that it put more greenhouse gases into the atmosphere than humans ever have. I hadn’t considered the numbers involved carefully before so this seemed possible to me. It didn’t occur to me that a famous personality with millions of listeners would just make something up and present it as fact.

Mt. Etna, Paroxysmal Eruption

Silly me. As an engineer, I decided to look into this Mt. Pinatubo thing and see what the numbers really were. If what Rush said was true, there’s nothing we can do about global warming. It’s a natural process and we have to deal with it.

What I found shocked me. Rush’s claim was so far beyond false, so ridiculous, there are no words for it. Not only do humans utterly overwhelm the output of Mt. Pinatubo, but we overwhelm all volcanic activity on the planet combined.

The problem here is comprehending the magnitudes of numbers. There are 8 BILLION people on the planet. Most people have trouble visualizing a thousand. Then imagine a thousand thousands. Most are completely lost at this point, and we’ve only reached one million. Now take the million and imagine a thousand of those, to get to one billion. Then times seven. The Bible said to be fruitful and multiply. Well, we did that. There are 480 million tons of human flesh walking around right now.

If we gave each person on Earth a 10 by 10 foot square of land, we’d occupy 25,200 square miles. Of course, I’ve lost everyone again because few can imagine a space that big. And, we need vastly more space than that in order to grow the food we eat, process our waste, obtain fresh water, and so forth.

Our impact on the planet is far greater than anything I had imagined. We are already using nearly all of the arable land on the planet to grow our food. Yes, we fly in planes and look out over vast spaces. There’s plenty of room. Actually, there isn’t because the majority of that space is not arable land. You can’t grow food in the Rocky Mountains, or Himalayas, or in the desert, Northern Canada, or Siberia.

There are vast regions of the Pacific Ocean that are fished out, stripped down to the bare seafloor, to satisfy our need for protein. Fishing fleets scrape the seafloor itself, leaving nothing but bare sand. When astronauts look down at night, whole regions of the Pacific Ocean are lit up by vast fishing fleets.

So, eight billion people, and half of them cook over open fires. Wood averages 50 percent carbon, by weight. So a pound of wood contains 1/2 pound of carbon. When you burn that pound of wood, each carbon atom combines with two oxygen atoms to form 1.7 pounds of CO2. Burning a pound of wood results in 1.7 pounds of CO2. With 3-1/2 billion people doing this, it adds up fast.

There are more than a billion cars (a thousand millions) driving around every day, burning gasoline. Everyone must eat. We humans slaughter 800 million chickens every day. Imagine the feed and farming required just to raise 800 million chickens every day. Farming burns fuel. Fishing fleets, and a billion cars, and trucks, trains, airplanes, ships, and power generation all burn fuel. Everyone living in northern climates must heat their homes in winter by burning large amounts of some kind of fuel.

Here are the numbers. Total volcanic activity, including undersea volcanoes produces 200 million tons of CO2, annually. Human activity produces 24 billion tons of CO2, annually. It’s not even close. We humans generate 120 times as much CO2 as all the volcanic activity in the world combined. In just two weeks, we generate, as much CO2 from burning wood for cooking, as the sum of all volcanic activity in a year.

To say that one volcano in the Philippines generated more CO2 than humans have ever produced?? Wow. In one fell swoop, I saw Rush Limbaugh for what he was.

Yet Rush’s little prank caught on. Ridiculous as it is, Rush’s Pinatubo Meme is still quoted 25 years on.