Thursday, August 26, 2010

Fun with (caffeinated) numbers...

I saw this post on Slashdot earlier:

This is a student project so the correct unit of energy is a "Library of Congress Stacked with Red Bull Instead of Books."

Now, you may convert that into Joules, if you care to.

I couldn't pass up that challenge...

The Library of Congress has 1,199km of shelf space.
A Red Bull can is 52mm in diameter.
A 250ml Red Bull can contains 481kJ of energy.

Doing the sums, I made the following estimate.

Assuming a single row of cans: 23,057,692 cans, and 1.109x10^13 Joules.

If we have a nominal shelf depth of, say, 250mm - let's call it 5 rows of cans - we get 115,288,461 cans, and 5.545x10^13 Joules.

For comparison, a kiloton of TNT releases 4.184 terajoules, so a Library of Congress of Red Bull contains the equivalent of about 13.25 kilotons of TNT - about 1 Hiroshima Bomb, give or take.

Fascinating stuff.

Tuesday, August 10, 2010

A taste of the future?

Headline from a news story this morning:

"Morgues fill as deaths double in sweltering Moscow"

Now, some of you will say "that's weather, it's got nothing to do with climate change". And you'd be right, mostly.

The difference is that, in a warming world, we can expect that extreme heat waves (and the forest fires that go along with them) will become more common. Already, record high temperatures are more than twice as likely to be broken as record lows. The last winter in Europe & the eastern US brought very heavy snowfalls & low temperatures. It was the coldest January in the UK for 23 years, according to the UK Met Office. At the same time, it was unseasonably warm over much of the Arctic, & the northwest US & western Canada (remember the problems they had with not enough snow for the winter olympics? They had to truck it in to some venues!).

Since then, it's been a pretty warm year. This Wikipedia page, listing all-time record temperatures for various countries, shows no less than ten new records have been set so far in 2010. Another 12 have been set in the last decade. That's all-time records, folks. 22 out of 58 have been broken in the last ten years.

The NOAA says that the January to June 2010 period was the warmest 6-month period on record. June 2010 is the warmest June on record, and is the fourth month in a row to set an all-time record.

Indications of a warming trend? Well, not in isolation, no - there's too much variability in weather for climatic trends to be statistically significant for anything less than about 15 years worth of records. However, it's certainly consistent with a warming trend. And if we go back far enough to get that statistical significance, there is quite a definite trend, so it's more appropriate to ask: "are current temperatures indicating any change from the previously established warming trend?" The answer is a categorical no. If anything, the current temps are tending toward an increased warming trend. There's definitely no evidence whatsoever that global warming is showing any sign of slowing down, more the opposite.

Back to heatwaves, the more serious implications are raised by this post on Skeptical Science. There comes a point where the human body is unable to shed heat, and body temperature starts to rise. At that point, you'd better have somewhere cool & air-conditioned to hide, or heat stroke is just a matter of time (just look at that Russian contestant in the Finnish sauna competition - 6 minutes in a 110ยบ sauna, and he keeled over and died).

So we're looking at some nasty consequences for our high-carbon diet over the past few centuries. (And those forest fires & peat fires are releasing even more carbon!)

A nice analogy I saw on another post on Skeptical Science: if you crash your car into a concrete wall at 80km/h, there's a small chance you'll walk away with just a few bruises. But is that any reason to drive straight at it?