"So why are the world making godzillion dollar decisions based on limited data?"

That's not why people are concerned about global warming. It's because we are pumping enormous amounts of CO_2 in the atmosphere. And CO_2 is known to be a greenhouse gas. This is not based on climate data that one could argue with, but it is based on "hard physics". You can observe in the lab and calculate from first principles the absorption spectrum of the CO_2 molecule so, you know exactly what its properties are.

The data is only relevant in so far as to validate the climate models. If you pump large amounts of CO_2 in the atmosphere then it is beyond reasonable doubt that it will get warmer. But you want to know exactly how strong the positive and negative feedback mechanisms are to predict the consequences of this.

Even if a particular region of the world would not get warmer that won't necessarily spare it from the negative consequences of global warming.