In the previous post on the most recent EPI rankings, Fat Knowledge pointed out that purchasing power parity and environmental performance are apparently related (they correlate at .58), and more strongly so than industrial growth, which is the case.
I tend to take for granted that the environmental movement is generally affluent, and to the extent that it is anti-capitalistic, opposes further economic and population growth rather than outright societal regression (although there is that element, too). Yet it is important to note that combatting environmental degradation seems to require wealth. Wealth alone is not sufficient, though, as several poorly-performing oil states demonstrate.
The environmental Kuznets curve conceptualizes environmental performance as being U-shaped, starting off and ending relatively well, but suffering during the developmental (China, India) stages. This isn't the case for the EPI rankings, with sub-Saharan Africa being at the bottom of the environmental and economic ladders.
So the EPI trend lends credence to the arguments China and India are making about how other industrialized nations had to cause a lot of environmental damage to get where they are today, to a point where they can ameliorate that damage, and so they too must be allowed to rapidly grow without restriction. I Don't know if that's what most environmentalists want to hear, but there is plenty of precedent for the developing nations' position on their own growth.