How to read climate news

I'm back from Denmark!

I've mentioned before that if you're looking at news about green industry, it's important to be aware of whether an article that talks about success or leadership in something like, say, solar is talking in terms of installed capacity or market share of products.

Something that's even MORE pernicious, though, is the inability of journalists to effectively communicate about emissions reduction. You should always be very wary about any article that talks about emissions reduction targets. If an article says something along the lines of "China pledges to cut emissions 20% by 2015", you haven't yet learned anything substantive. The article might mean one of several things:

1) [Most likely] China has pledged to cut emissions per unit GDP by 20% by 2015. (This is most likely because it's how China tends to make pledges. Obviously, if it's growing at 10%, over a 5 year period, this target still results in a meaningful emissions RISE in absolute terms.)

2) [Meaningfully less likely] China has actually pledged to cut emissions by 20% relative to today's emissions. (Less likely, because right now China hasn't made any absolute emissions cuts, and this kind of number would most likely have had to have been backed out of a per-unit pledge, which news people don't seem to know how to do.)

3) [Highly unlikely] China has pledged to cut emissions by 20% from 1990 numbers. (Ha ha hah, don't expect to see this anytime soon. It's an even harder bar to clear, but it's what Europe is usually talking about when it talks about its emissions cuts - absolute cuts, relative to 1990 - because that's the Kyoto framework. So that's the standardized format for pledges, so to speak.)

4) [Possible] China has pledged to cut emissions by 20% from business as usual (BAU) by 2015, ie what they're expected to be emitting by 2015 if they did nothing and let society take its course. (Usually you'd only see this if a journalist was reporting on a third-party analysis, because it's not how China does its pledges, and there's the question of whose BAU scenario you're using, etc.)

Europe, as noted, tends to report in absolute cuts relative to 1990 (though it doesn't hurt to check). I'm actually unsure offhand what the US does - ie, I am uncertain whether the voluntary 17% pledge cut we made at Copenhagen in 2009 is relative to 2009 or to 1990, although I'm pretty sure it's an absolute and not a per-unit cut. Hey, I should check that. But not before I post!