What’s a Degree Here or There Really Matter?
In ASP’s “10 Facts About Climate Change,” we list some of the harmful effects from a change of just a few degrees:
1) An increase of 3.8°F would cause a catastrophic decrease in plant and animal life in the Arctic region.
2) An increase of 5.4°F would decrease yields for all major cereal crops in all major regions of production. At low latitudes, some crops could see a yield decrease of over 20%.
3) An increase of 7.2°F would double the frequency of drought events across southern Africa, South East Asia, and the Mediterranean basin.
4) Increases of 7.2°F would cause sea levels to rise as much as 31 inches by the end of the century.
Many people find this hard to understand. How would an increase of a few degrees have such radical effects? After all, with a nudge of the thermostat up or down a degree, most people would not perceive the difference.
The problem lies with the poor comparison. It also showcases how hard it is to understand different scales of size.
Take an example closer to home: yourself. When you have a fever, your body temperature goes over 100°F. During this time, you feel awful and very likely don’t want to get out of bed. No one denies the validity of your symptoms and pain even though your temperature is only a “few” degrees more than the average body temperature of 98.6°F. A few measly degrees really can make a difference.
Back to climate change. Using temperature as an indicator of climate change really masks how much energy is being added to the environment. When coking two different pots full of water on the stove, it takes longer to get the larger pot to boil than the smaller pot. This is because it requires more heat and energy to get it to the “same place.” Now supersize and generalize this to the Earth and you get a sense of why likening the world to your living room misses the point.
Let’s try to get a scale on how much energy has been added.
On average, there is 70 cubic miles less arctic ice each year due to global warming. To melt this much ice, 8.6 x 10^19 (86 quintillion or 86 billion billion) Joules of energy is needed. For comparison, total U.S. energy consumption in 2009 was about 1 x 10^20 (100 quintillion or 100 billion billion) Joules. That means the equivalent of 86% of yearly U.S. energy consumption (which includes every company, city, and 313 million citizens within the borders) is absorbed by melting ice more than without climate change. And this is not even 2% of the total heat absorbed.
It is estimated that every second 4 atomic bombs worth of heat is absorbed by the earth due to human caused global warming. At 250 trillion Joules per second, it only takes four days for the earth to heat the same amount of energy that the United States uses in a year.
The earth is warming, and it’s not by just a little bit.
