There have been anomalies with several other cacti also. P. strobiliformis, which usually flowers in August, flowered copiously in June-July, and again, copiously, in August-September. My large L. Tegeleriana, which usually flowers in September, flowered in July, and then flowered repeatedly, through until the end of December. It hasn't only been happening with Cacti, either, as listeners to Gardener's Question-Time over the past year will be aware.
In October 2010 there was an article in Nature suggesting that the quality of sunlight had changed, and that whilst we were getting the same amount of radiation, we were receiving eight times less at the ultra-violet end of the spectrum than we would expect even at a sunspot minimum (and, I presume, in consequence, more at the infra-red end). At the same time, my doctor tells me, there is a sudden outbreak of vitamin-D deficiency. (Our skin uses ultra-violet to produce vitamin-D).
Ultra-violet radiation warms the upper atmosphere. Infra-red radiation warms the ground. Quite apart from any effect this might be having on air- and sea- currents, and hence, perhaps, climate change, could it, I wonder, explain the flowering anomalies of our plants?