No, nobody is making accurate predictions right now and that's the fundamental problem. We want to enact change on future predictions, but the models we're using to predict things have a history that's shown them to be unreliable. Each time a prediction fails to pass it ends up undermining the entire system of climate modeling more and more. We can't expect national bodies to engage in anything other convenient changes based on predictions with a poor track record. This is why you need accuracy above all.
As for the temperature increase, I don't picture things in such a polarized fashion. I think there's little doubt that humans are contributing to climate change. But what really confounds this issue is that climate, even absent humanity, is a very unstable system. These [1] are the data from the ice cores over the past 800k years, so literally before humanity existed. And you'll note a regular and often quite extreme shift in temperatures. For instance check out the end of the ice age before our most recent one - about 130k years ago. In an extremely brief period of time the temperatures skyrocketed something like 14 degrees celcius. We then gradually made our way out of that ice age hitting unprecedented lows dropping some 15 degrees celcius before once again starting an extremely rapid rise about 12,000 years ago which we are now in. And we've yet to hit the 'normal' highs of times past. So even if humans did not exist, we would almost certainly be seeing rapid warming.
As for his comments referencing temperature, I'm also not entirely sure. His comment was somewhat unusual since the last ice age obviously did not only last 8,000 years. It also didn't end 10,000 years ago (though that's not too far off). And it would also be quite unusual for a UN speaker to use Fahrenheit. In this case, I think we can dodge this issue since 0.68C = 1.2F and that's given not only a failure to reverse carbon emissions but an unprecedented spike in them, so the point holds true in either case. Extreme CO2 increase = bottom or below the bottom of "most conservative scientific estimates" in temperature increases? We can't expect nations to engage in urgent action based on data like this.
[1] - https://en.wikipedia.org/wiki/Global_temperature_record#/med...
[2] - https://en.wikipedia.org/wiki/4.2_kiloyear_event
