The benefits of the US being part of the Agreement, as I see it, include being able to maintain at least a facade of leadership in world affairs. Sure, that's "vague," as @adurso points out. Things like leadership in world affairs, diplomacy, etc., ARE vague--hard to quantify. The effects are cumulative over various agreements, institutions, etc., that countries take part in. As the US continues to pull out of or away from one thing after another--we don't even sound 100% committed to NATO anymore--we lose our influence in the world bit by bit.
The main reason Trump pulled out of the Agreement, as I see it, is to make a big show of it--theatrics, with him at the center of the stage. What if the US had not pulled out that way but had simply flouted the terms by not contributing what the world expected of the US? Maybe I overlooked something, but from my reading of it the Agreement doesn't have teeth--contributions are self-determined by each country, and there are no penalties. What would the consequences have been? Trump is good at making excuses and spinning things, and I'm sure he could have come up with something that kept the rest of the world at bay. If the US had simply dragged its feet and not lived up to the spirit of the Agreement, it would have had essentially the same effect as not participating in it in the first place, but would have gotten less attention. It wouldn't be all over the news media, and we wouldn't be having this discussion.
This has been explained numerous times but once more apparently. The biggest problem that should piss you off the most is that cited in the agreement (China and India specifically) are allowed to build an unlimited amount of coal fired plants with no time limit.
As I mentioned before, the largest polluters will only continue to pollute and not cut their emissions for at least another 13 years. This information is publicly available if you want to refute my claim.
The world expected the US to make many payments in the coming years to the Green Climate Fund. An amount that would be close to a $100 billion, by far the largest contributor to the fund using government funds AKA tax dollars. This does not include private businesses and corporations who would add another few billion. This amount would be triple what the rest of the world would contribute to the fund.
The main reason Trump pulled out of the Agreement, as I see it, is to make a big show of it--theatrics, with him at the center of the stage. What if the US had not pulled out that way but had simply flouted the terms by not contributing what the world expected of the US? Maybe I overlooked something, but from my reading of it the Agreement doesn't have teeth--contributions are self-determined by each country, and there are no penalties. What would the consequences have been? Trump is good at making excuses and spinning things, and I'm sure he could have come up with something that kept the rest of the world at bay. If the US had simply dragged its feet and not lived up to the spirit of the Agreement, it would have had essentially the same effect as not participating in it in the first place, but would have gotten less attention. It wouldn't be all over the news media, and we wouldn't be having this discussion.