> Here’s a little contest: share up to three of the most salient facts that you can think of about climate change. I will integrate the winners into the paragraph on environmental crisis / sustainable development.

Bill McKibben's answer is not bad:

* Bill McKibben, [Global warming's terrifying new math: three simple numbers that add up to global catastrophe - and that make clear who the real enemy is](http://www.rollingstone.com/politics/news/global-warmings-terrifying-new-math-20120719), *Rolling Stone*, 19 August 2012.

1. The First Number: 2° Celsius - the supposed "safe level" of global warming.

1. The Second Number: 565 Gigatons - an estimate of how much more CO2 we can dump into the air while staying within this safe level.

1. The Third Number: 2,795 Gigatons - how much CO2 is already on the books: that is, "already contained in the proven coal and oil and gas reserves of the fossil-fuel companies, and the countries (think Venezuela or Kuwait) that act like fossil-fuel companies."

This is five times the second number.

For more detail, see:

* Carbon Tracker Initiative, [The carbon bubble](http://www.carbontracker.org/wastedcapital).

Must-read stuff!