Can we definitively say that any one “freak” record-breaking event was caused by the increased concentrations of carbon in the atmosphere? No. It doesn’t work like that.
Can we say the pattern which connects, the simultaneity and power of these outlier, 100-year whatevers, is very much the kind of thing that we expect, given what climate models have indicated are expected outcomes from increased greenhouse gas concentrations? ‘Fraid so, well, most likely anyway. Other explanations strain the logic of probability. More frightening still – a lot of it is going faster than many worst-case scenarios. Sure, our models aren’t perfect yet. It’s science – there’s no such thing as a perfect model or 100% certainty. But we don’t need that to get off our butts and do what we can to prevent a highly-probably, totally awful future. The foot-dragging, hemming and hawing has got to stop.