I mean you can't prove the connection because it takes years and years of observations and data to establish the evidence. But yeah, larger storms like these are fully in line with what you'd expect from a warming climate. The ocean water has been half a degree warmer than usual in the Caribbean for instance, and the link between warming oceans and global warming has been established. Half a degree doesn't sound much but this is where the misunderstood butterfly effect metaphor comes from. It was coined to describe how small variables could end up having a huge impact on complex systems like hurricanes.
Meteorologists mentioned on Twitter how Irma, when it first formed, could technically have been classified as a Class 6 storm (which doesn't exist) because it had already exceeded the possible maximum rotational speed according to the model. A warmer ocean means that more warm air will be able to rise up during the depression.
