While as someone of a science background I agree this quote, I do think scientist have done themselves a dis-service as many non-scientists mis-use this quote against scientists.The IPCC reports are consensus reports.not to be confused with "proven science".Albert Einstein on proven science-
No amount of experimentation can ever prove me right; a single experiment can prove me wrong.
Read more at No amount of experimentation can ever prove me right; a single experiment can prove me wrong. - Albert Einstein at BrainyQuote
There are many who use this idea of absolute proof as an argument against science, when the weight of evidence is quite clearly against their own argument, precisely because this idea of absolute proof resonates with scientists (who are unusual in this regards). It is in fact an impossible burden to "prove" science because you can never do so in many, if not most, instances (all we normally can say is that we have yet to identify contradictory evidence). Yet, the lawyers (who in recent times seem to be the main naysayers against science, albeit in politicians garb) set themselves a much lower burden given their reference point (courts) requires only that things are judged on the balance of the evidence.
I'm not incidentally arguing either method is correct, just that you should apply the some measurement of evidence to yourself as you would do with others.