It is difficult, though not impossible, to say how individual events are influenced by climate change. It is simpler to tell whether the overall numbers are increasing.
Even at the time of the last IPCC report in 2007, the trends for extreme heat, droughts and intense rainfall were already clearly upward. Not only are these trends continuing, but the weather is also becoming even more extreme than was predicted.
For instance, a study this year of ocean-salinity data from between 1950 and 2000 by the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) found that the global water cycle – the rate at which water evaporates and falls as rain – has increased at double the pace projected by models that aim to simulate the global climate.