A key prediction of climate change, misrepresented by Roger's Rabbits on 15 March, is that whatever weather you get now, you will get it bigger in the future. Summers that are unusually cold and wet (last year) or hot and dry (this year) are exactly what is predicted for a variable climate such as ours. Extreme conditions are entirely consistent with the predictions of climate change.
Thus, global warming does not mean a gentle change towards slightly warmer summers. It means bigger storms, stronger winds, fires, flooding, extreme temperatures and more intense cyclones (note to self, visit Australia only in winter). While it also predicts slowly rising sea levels, that rise might not be a progressive linear process.
More importantly for coastal communities is that storm surges that were previously tolerable will become catastrophic. Kiribati (highest point around 2.2 m) is already looking at abandoning ship and moving to Fiji. Samoa recently lost much of its coastal roadway. We have all seen the photos from New Jersey.
The graphic shows the pattern from 1980 to 2010, and its trend is clear (see http://makewealthhistory.org/2011/05/30/the-number-of-natural-disasters-is-on-the-rise/). The data are from EM-DAT, the international disasters database, and are reported by the UN. The graph has flattened out lately, but the increase is obvious. To put that down to natural environmental variation is naïve, not to mention unrealistic.
We need to plan now for a future that is not predicted by past experience. We in Aotearoa are very well placed to deal with that change, but pretending that it is not happening is not an option.

Dr Ian McLean, Tauranga.