Professor Peter Stott:

The ozone is an example of where scientific evidence and international co-operation have shown that such a global challenge can be solved in collaboration with the relevant industries and so forth. The ozone hole is starting to recover so we have seen how we turned the corner on that. The thing about the global temperatures is that due to the long timescales in terms of how the climate works and in terms of this thing called "commitment", the scenario we are looking at is stabilising temperatures, at least over timescales of decades. To reduce temperatures, one is in the scenario of trying to take greenhouse gases out of the atmosphere. The analogy of the ozone hole, where the ozone hole recovered, for the climate change problem would be that potentially humanity would succeed collectively in stabilising temperatures. If they were stabilised at a sufficiently low level, that would be an achievement comparable to the ozone hole. The reason for that in terms of stabilisation is the long timescales and the long commitment that past emissions have made to our warming. The issue with climate change is that our emissions cumulatively lead to an overall level of warming, so that would be the analogous success there.