I agree also that indeed SOME reefs will show improvements in the future due to better management. However, when leveraged against ALL the reefs in the world, I don't think that we are going to see overall movement in the right direction. Heck, down here in the Keys, there are probably more laws and protected zones than just about any reef on Earth. But the reefs here aren't doing that great. I wouldn't say that they are sliding terribly fast either though. The biggest culprits are probably from the runoff of fertilizers from the sugar plantations in the Everglades, and then just simple human activity like boating, fishing, diving, and having a high population density 5 miles from the reef. Finding acropora is a mission these days, although the few colonies that I see look like they are doing well, so we can hope that in 10-20 years we will have staghorn and elkhorn thickets like there used to be back in the 70s.
As for reversing climate change, I'd say that at best, to reverse the trend of global warming we are looking at a nearly impossible wall of deaf ears. The US won't approve the Kyoto protocol, and even that wouldn't be enough to do much, but it certainly is a great first step. I just read today that the EPA is looking to open up a loophole to allow the biggest polluters to pollute even more.
(See here) That is our "Environmental PROTECTION agency" mind you...If "developed" nations like the USA won't set an expample, then how can we expect developing nations to follow along? Developed nations, such as ourselves, are where we are today because we did our developing in another era, when there was no thought given to pollution. Now of course we want to hold everyone else to higher Most developing nations, especially tropical island nations simply burn their trash in the backyard (or often in the street). I recall from my experience in the Solomon Islands, the sight of batteries laying all over the place as the smell of trash hung in the air. Without electricity, they use these disposable batteries (it's pretty tough to use rechargeable batteries without electricity), and they just throw them out into their gardens or street or literally where ever. It is easy for us to point blame at this ignorance, but shoot, I don't have a clue what happens to all my trash once the garbage truck takes it away.
Another vein in the aging body of humanity...