It will never be irreversible, the experts that claim that it is have other motives for saying so.
Hurricanes, and to a lesser extent Blizzards and Thunderstorms are all a part of Nature's Air Conditioner. As the global temperatures increase the severity of such storms will increase. Because the stronger the storms, the more the planet is cooled by it. The faster we stop putting these pollutants into the air (CO2 being the big one) the sooner our climate will return to normal. Part of the reason people are screaming that it could be irreversible is that the few people that slow down their emissions are being outshadowed by the many that are reving it up into high gear. The United States is the biggest contributor to Greenhouse gases in the world, but if you were to go back twenty years, you'll see that the percentage of global output the US is has dropped significantly. Why? Because the US has curbed it on their own, while countries in Eastern Europe, Asia and Africa are jumpstarting their industries with little or no supervision.
A non-partisan treaty that excludes no one, and sets flexible limits will be far more effective than Kyoto and its successors will ever be. How many European countries are nowhere near their limits? Russia is going to get very rich off Kyoto. Since they seem to be the only signatory that will come in UNDER their limit. (And way under at that)