Do you seriously consider the COP junket as "business"?
I have traveled overseas on business on numerous occasions, and you are correct, I didn't pay for myself. Sometimes it was just me, demonstrating a product or conducting a field trial. I would be doing business with 2 or 3, maybe 5 people from one other company, and I had to return home with something tangible, like an order or contract, in order to justify the trip. One or twice, I was part of a small group, taking part in a negotiation with another small group, or problem solving. Whenever I was sent overseas, there were always objectives to be met, and there was always follow-up to make sure they had been met. Can you say the same about COP?
And 70,000 people. What could I (or anyone else) possibly hope to achieve trying to negotiate with 70,000 people? There were probably no more than 200 genuine decision makers at COP, and 69,800 there for a holiday at someone else's expense.