I’ve been reading different arguments about global warming lately and I ran across a claim on the sites of several people arguing against global warming.
Man-made carbon dioxide emissions throughout human history constitute less than 0.00022 percent of the total naturally emitted from the mantle of the earth during geological history.
I’ll admit when I first read this I thought, is this really true? Doesn’t this hurt man made global warming arguments? Then I took a moment and considered the statement more carefully. the 0.00022 number provided is based upon a comparison of carbon dioxide for the entire geological history of the earth, which if you remember is 4.3 billion years. However, human cased global warming is a recent issue caused by high CO2 output by humans. Almost all of this CO2 output has happened in the last two to three hundred years, which means the real question is how much extra CO2 have we added to environment recently not in all of earths history.
Let’s not stop here though. Assuming this number is correct (I couldn’t verify anywhere) then lets calculate what percentage of of the earth’s CO2 has come from humans in the past couple of hundred years. Fair warning I have never considered math to be my strongest subject so feel free to point it out to me if I make a mistake in my calculations.
First we will base the calculations on the last 300 years. So to find out what percentage of 4.3 billion 300 is we divide them.
divided by 4,300,000,000
= 6.9-8 or 0.000000069
divided by 6.9-8
That’s right, the amount of CO2 produced by humans is almost thirty-two hundred times more than the amount of CO2 naturally produced by the earth in the same time frame, even based on the number provided by those arguing against man made global warming. So, this number, is actually strong support for man made global warming instead of evidence against it. Making the argument that it is a very small percentage of the CO2 produced through all of human history is like claiming a flood doesn’t exist because the amount the amount of rain that caused it is a very small percentage of the overall rain fall in that area in the last hundred years.