There is legitimate conversation on both sides of climate change, with most 2017 Democrats+Republicans(Politicians and general public alike) accepting that Climate Change is real, and it is only a matter of how much of it is reasonably caused by humans and how much of it can reasonably be slowed down/reversed by humans. I'm not gonna debate the specifics on each side, but I do happen the lean towards the right on this one, we literally don't know how much human activity affects climate versus other planetary/weather like systems that are currently in play.

Anyways, this context was necessary in showing that Trump probably understands this very basic analysis. However, he is still likely to turn down the deal. Why?

My Opinion: Because the US does not have the advantage that most other dictatorships have(counting Russia here as well even if it's not an extreme example)...those dictatorships have cultivated a reputation, over a very long period of time, that they do not bluff. Yes, that's it. Simple.

In general most presidents elected to the USA have not been extremists by any sense. Trump may not be extreme in policy, but in conduct he is - just as impactful. But that's Trump, not the USA. These are different entities. The USA's reputation is not Trump's reputation. Certainly not after 5-6 months, and probably not even after 4 years. When it comes to the principled non-bluff decisions that Trump is going to have to make on Russia, North Korea, etc, he is going to ahve to have his opponents believe he will not bluff.

But he is up against the general reputation of the USA that does not immediately evaporate once he got elected. We have a reputation as pushovers, and no it's not just Obama, in general the US has been willing to compromise and bend over backwards, financially, militarily, politically, just to maintain peace. I could go on but you should get the point by now. He can very well help Climate Research/Projects later on, but this is an instance where almost every significant nation, leader, expert, politician, celebrity, CEO, is going against him. It is an opportunity to cultivate a new impression of America.

Whether you think that is important may be another conversation.

He has to do something not only for the environment, since we ARE in an abnormal period of climate change that just can't be a simple collision of natural factors, it would be bad for the US economy in the long run.

The future is solar and green. If other countries start imposing heavier emission laws and banning fossil fuel cars, the US will be hit heavily in it's exports if it languishes.

If the US doesn't do anything about climate change in the next few years, it will result in thousands of deaths more in the future.

All these people killed because of one selfish guy.

What's their to discuss about climate change just because an old asshole in a big white house say climate change is fake science doesn't mean 97%of scientists who research climate change are wrong. There where 195 countries that agreed to the Paris climate act. The last time world politics where so much in agreeement was that WW2 was bad. Problem is not a single countrie really wants to pay the price since its pretty simple to decrease the emission of greenhouse gasses. There should be a global carbon tax which demands companies charging money for every ton of carbon emission. As for human having an influence on climate change well since the industrial revolution the CO2 concentration in the atmosphere has increased with nearly 50% and the CO2 levels haven't been this high in the atmosphere in 1.000.000 years judging from analysing Flora and Fauna, Ice structures, Ground layers and O2 isotopes. Over that time the maximum atmospheric levels where south of 300 ppm at this moment they are over 400 ppm and closing in on the 410ppm.
https://nca2009.globalchange.gov/global-climate-change/index.html

But if we are going to treat climate change like a myth or it being real or not to be a point up for discussion. Can we really afford to take that risc. I live 2 meters below sea level and I know what's going to happen when that sea levels rises with a meter and the rivers needing to transport mote water to a sea that's rising. If climate change won't be put to a hold The western part of the Netherlands may not exist anymore in 2200.

The problem with Trump leaving the Paris Agreement is inevitably when there will be a Democrat in the White House and they sign a new climate agreement; the terms will mostly likely be more harsh than Paris. On top of that, American coal companies lose overall influence to European and Chinese rivals that would dictate the rules.

I understand the appeal of Trump's America First policy but it couldn't have come at a worse possible time with a resurgent Russia and rising China.

I'll just leave this here. That's an awfully sharp change in temperature, but I'm sure it's natural and nothing we can do anything about.

I will never understand the logic of some who are like "there could be climate change because of us but it could have also other reasons, that's why we don't have to do something". I mean, even if the chance would be only 30% that we have something to do with it then countries should say "yes, we have to do something".

In the worst case we do it without effect but it still won't hurt us to do it. In the best case this planet will see millions of people less who die and hundreds of millions of people less who will be refugees.

To be honest, humans are stupid, we are probably destined to "destroy" the ecosystem of Earth, it will force us to have to leave Earth and live in space/colonize other planets. That's how this movie ends, I don't see that changing. It's inevitable, we only change something if it's a pressing immediate need, we are too short sighted, kinda like the kid who will tell himself for the next school project/test he's going to study early next time, but he always ends up at 3 AM the night before trying to cram because he procrastinated all week. That's us as a species in a nutshell, lol. 

No, stepping out brings you at a disadvantage. Do you honestly believe people will want American coal and cars when the rest of the world runs solar and electrical. This is going to be an economic disaster in the long run.

Climate change exists and we need to do something about it but not at the cost of american jobs/money for a barely measurable difference in climate.