Monday, June 30, 2008

Carbon Dioxide and the Magic of Exponential Growth

If a frog is put into a pot of boiling water he will immediately jump out of the pot and save himself. But if the same frog is put into a pot of water at room temperature and the water is slowly heated, the frog will not notice the water is getting hotter until it is too late. The frog is a lot like us. He is built to notice and respond to sudden changes in his environment but is not as good at responding to gradual changes.

Two hundred years ago, at the beginning of the industrial revolution, the amount of carbon dioxide in the atmosphere was 280 parts per million (ppm). It is now 385 ppm and increasing at a rate of 1.7% a year, due largely to the industrial development of China and India, and their increasing dependence on coal – the dirtiest of fossil fuels.

At 1.7% per year the amount of CO2 emissions will double in 43 years. That's the magic of exponential growth. As the world industrializes, more and more energy is needed and if that energy is from fossil fuels, the amount of CO2 emissions keeps growing too.

At this rate of growth, before the end of the century the amount of carbon dioxide in the atmosphere will reach and surpass 1000 ppm. Carbon dioxide is toxic to the human heart causing decreasing contractile force as well as difficulty breathing. At concentrations of 1000 ppm CO2 causes discomfort in the form of nausea and headaches for about 20% of people. At concentrations of 2000 ppm – which we would reach within a century – the majority of people would experience discomfort. At that point, we might want to live outside all the time because the concentration of CO2 inside buildings would be even higher.

Although it is true that plants need carbon dioxide to grow, not all plants would benefit from increased levels of CO2. Specifically, our food crops would not do as well, but apparently weeds would thrive under these conditions.

Is this the kind of world we can look forward to? A world of mass hunger, misery, and nausea? Notice I haven't even mentioned global warming up until now. What is driving almost all the greatest threats to humanity, including global warming, is industrialization and economic growth.

People who believe we can continue on with business as usual are a lot like that frog in the pot – they don't notice any difference from day to day. It's not hotter today than it was yesterday. More and more children are getting asthma, but the increase is gradual so we don't notice. More people are getting cancer from the increased amounts of toxins in the environment, but the increase is so gradual that we barely notice it. Forests, which are net absorbers of CO2, are being cut down at an alarming rate – but we don't notice it because it's happening somewhere else.

Some people are worse than the frog. They're more like the ostrich that hides its head in the sand. They find the consequences of this news too overwhelming. They are too chicken to face up to the fact that we have to stop the growth of industrial output or we won't survive.


  1. The most recent increase in CO2 recorded from Mauna Loa and listed on the NOAA website was 1.66 ppm for 2008.

    That represents an increase on the 2007 of 383.71 of just 0.4%

    So ... how did you deduce that CO2 is increasing at 3.2% per year ?

  2. The rise-rate is growing with 1.7% per year. Still hugely problematic.

  3. Thanks for showing interest in my article. I have made some corrections, based on your estimate of the rate. If you have any other suggestions I'm open to hearing them.
    By the way, why do you need to be anonymous?