moment of truth

This was in the Sun-Herald two weeks ago (31 October) and I thought it was a nice little vignette:

The world-renowned environmentalist David Suzuki spoke at the Opera House last week, and presented a case that the planet is in the 59th minute of a suicidal path of economic growth.

(...) imagine putting one bacterial cell, which divides every minute, into a test tube full of food. This is exponential growth, which is the path of humanity when it believes in unlimited economic growth.

"At time zero you have one cell; one minute you have two; two minutes you have four; three minutes you have eight; four minutes you have 16. That is exponential growth and at 60 minutes the test tube is completely full of bacteria and there is no food left, a 60-minute cycle. When is the test tube only half full? Well, the answer, of course is at 59 minutes; but a minute later it is filled. So at 58 minutes it is 25% full; 57 minutes 10.5% full. At 55 minutes of the 60-minute cycle it is only 3% full.

"So, if at 55 minutes one of the bacteria said to its companions that they had a population problem, the other bacteria would be incredulous because 97% of the test tube would be empty and they had been around for 55 minutes. Yet they would have only 5 minutes left. How do we add even a fraction of 1% more of air, water, soil or biodiversity? We cannot. The biosphere is fixed and finite, and every biologist I have talked to agrees with me, we are past the 59th minute."