This is a follow-up to my CO2 primer posted a while back. I wanted to add a sense of scale to the nature of the problem here, so people might get a feeling for the level of “critical mass” we must deal with.
Annually, the combined ice loss of the Arctic, Antarctic, Greenland, and glacial sources equates to approximately 700 billion tons of ice. 700 billion tons every year. (IPCC figures)
That right there is an enormous amount of energy – let’s look at it from a high-school chemistry standpoint:
I’ll simplify it a bit, as we go – let’s assume all that ice is already at zero degrees C when it melts, and it melts into 0 degrees C water (it doesn’t, really, it is colder and works its way to zero, then melts and keeps warming). So we’re *only* going to look at the energy required to melt that ice. To melt ice is to have it move from one state (solid, ice) to another (liquid, water). When it’s solid, it has bonds between all the molecules that need to be broken and reformed into a different set of bonds, and it takes an input of energy to do that.
It takes 80 calories to melt one gram of ice. 700 billion tons of ice is 700 million billion grams of ice (1 ton = 1,000 kg, 1kg = 1,000 g, therefore 1 ton = 1,000 * 1,000 g = 1,000,000 grams).
So for each ton, that’s 80 million calories of energy. To melt 7 tons takes 560 million calories. 700 tons would be 56,000 million calories. 700 billion tons is 56,000 million billion calories. That’s beyond normal comprehension, so let’s turn that into something we might recognize.
The USDA recommended daily food balance comes in at about 2,000 “calories” (these are dietary calories, equal to 1,000 calories in the chemistry sense) per person per day. For the entire country of 300 million people, that makes 600 billion calories of food per day. Let’s assume we’re overeager eaters, and we end up eating 700 billion calories because we go to Wendy’s too often. Turning that into “chemistry” calories means 700 thousand billion. Now we’re starting to see numbers we recognize…
One year’s melt requires 56,000 million billion calories. Let’s bring that down to one day’s melt: divide 56,000 by 365 and we get 153 (I’ll drop the fraction). So every day the ice consumes 153 million billion calories.
We’re going to try to turn that number into “number of food-days for the USA”, so to get that we’re going to end up dividing one with the other – ice calories divided by food calories. So first, drop the billion on each side.
Now we’re down to 700,000 on one side and 153 million on the other. Let’s divide. I get 218 from that (again, dropping fractions). This indicates that the amount of ice melting into water, EVERY DAY, absorbs the energy equivalent of the USA’s dietary requirements 218 times.
The United States could eat a full day’s worth of food for twenty-nine weeks (a little more than seven months, start January 1 and go all the way through your July 4th cookout), and still not quite reach the total energy consumption required to melt the amount of ice the planet is losing on average every day.
Now here’s the kicker that I hope will give you some reason to start asking “what can I do?”:
Where is all that energy going to go when the ice runs out?