As many of you have heard, the Earth has been getting warmer, rapidly, since the industrial revolution. And as many of you have also heard, there is, historically, a link between greenhouse gases and temperature here on the Earth.
How could something as small as a human being affect the climate/temperature of the entire Earth?
The analogy is good old-fashioned water torture. What harm can one drop of water do to you? Pretty much nothing, of course. But what if you randomly dripped cold water on the same exact spot for hours or even days on end? The result is that the victim can go insane (as confirmed by mythbusters) from this. It’s because a cumulative effect, over a long period of time, can be significant even for a small thing.
But this is Scienceblogs, and I’m a scientist. We don’t reason by analogy here except for help in explaining. Instead, if we want to test something, we do the science. So let’s take a look at what we’ve been doing to the Earth. The United States, right now, is responsible for between 20 and 25% of the greenhouse gas emissions in the world, most of which is carbon dioxide. Check out the latest (2007) statistics:
That’s a lot of gas, but surely it’s insignificant compared with the entire Earth’s atmosphere! And, of course, it is. The mass of the entire Earth’s atmosphere is somewhere between 5,000 and 5,300 trillion metric tonnes and so this 6 billion metric tonnes that we put out could hardly ruin the planet, right? Well, we’re not the only country on Earth, but moreover, 2006/7 wasn’t the only time we put large amounts of carbon dioxide into the atmosphere. Take a look at the long-term statistics of carbon dioxide released from fossil fuels.
Well, doing the math on these statistics, from 1800 to 1950, the world’s human population released 300 billion tonnes of carbon dioxide into the atmosphere. You’ll notice that, because this was such a (relatively) small amount released over a (relatively) long time, the effect on carbon dioxide concentration wasn’t very pronounced.
But over the next 30 years, from 1950-1980, we really ramped up out fossil fuel consumption, and over those 30 years we put out 390 billion tonnes — more than the past 150 years — in just 3 decades. You’ll notice that the rise in carbon dioxide concentration over that time is pretty steep.
And as for the last 29 years, from 1980-2009? We’ve put out more fossil fuels than ever before: an unprecedented 725 billion tonnes over that timespan. So what does all of this mean for our atmosphere? Could humanity — a few billion tiny animals — really affect the entire atmosphere of our planet?
Well, our 5.3 trillion tonne atmosphere is made up of the following:
- Molecular Nitrogen — 78.08%
- Molecular Oxygen — 20.95%
- Monatomic Argon — 0.93%
- Other — 0.04%
Nitrogen, oxygen, argon, and a little bit of other stuff. How bad could adding this carbon dioxide to the atmosphere be? (Aside from killing the great barrier reef, of course.)
Keeping with the current trends, we will have double the amount of carbon dioxide in our atmosphere by 2040 than we did in 1800, and this carbon dioxide is forcing the temperature increases we’re seeing now. Whether you’re convinced by this convincing evidence that has convinced climate scientists for decades or not doesn’t matter. What matters is that we have hundreds of billions of tonnes of extra carbon dioxide in our atmosphere, with no known way to deal with it.
The least we can do is stop making it worse, which means to stop burning fossil fuels, or — at the very least — to burn as little as possible as slowly as possible. And that’s my concluding thoughts to you this Earth Week!