The book was published in 1984 (of all years!, Orwell would be horrified at how his book has been used by some alarmists as a manual rather than as a warning).
The Australian writer below observes that 'things have only got worse in terms of Green alarmism' since then.
Emboldening of last sentence by me. See the original (linked to in title above) for the rest of the article, and for more references.
Note added 16 Novermber 2012
Just seen this blog post from Samizdate which was in response to the above post and which contains some useful observations as well as some comments from others: http://www.samizdata.net/blog/archives/2012/04/environmentalis_1.html