I believe we need to do something about global warming, as a moral obligation and a potential means to maximize the human race's survival. But the way the Left is trying to convince the rest of the world has become really ridiculous. And I partially blame them for this kind of outcome.
Let me give you an absurd statement from Greenpeace:
"There’s
no more debating if climate change is a reality.
Scientists agree: the world is getting warmer and human activity is largely responsible."
Source:
http://www.greenpeace.org/usa/global-warming/climate-science/- The second sentence is basically implying that climate change is a scientific fact because scientists agree. Since when did we accept something as a scientific fact based on consensus? You will notice in the greenpeace page that they describe the greenhouse effect to explain the climate change in Earth. Well, is this hypothesis scientifically proven?
One should easily recognize that there is no way we can prove such a claim. One would have to create two planets (or equivalent models) in same conditions as Earth, create CO2 driven greenhouse effect on one planet, and show that it significantly contributes to warming compared to the second one. We obviously cannot do this.
So what these "scientists" resort to is a bunch of descriptive statistics such as how much correlation is there (not causation) between CO2 and temperature, how fast is ice melting, how frequent is extreme weather happening ... These can be evidences but they are NOT evidences that can be used to accept / reject the original hypothesis! And yet they throw out a statement like "scientists agree that climate change is due to human activity"? What have learned in their PhD training??
- Then the first sentence: "There is no more debating". WTF! So you use supposedly scientific arguments to establish climate change is a reality, yet you say there is no debate? Any scientific fact should be refutable and tried to be disapproved. Who are you to say there is no more debating? Doesn't this sound like religious extremists saying you should never doubt the holy words or that Earth is flat?
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Now here is the thing, we don't need to use science to convince people to do something about climate change (I hear rationalists gasping). What we need to do is to frame this issue as an moral issue and convince enough people that caring about our climate is a morally good thing to do. Same as treating others as you want to be treated is a morally good thing to do! These are what I consider as moral truths, different from scientific truths that you validate / falsify empirically, but just as if not more important than scientific truths because they have held together the humanity for millions of years (consider how long scientific truths have been in play in contrast). If you are talking to a religious zealot, tell him/her the story of Tower of Babel or any flood myth to remind them the consequences of human hubris and that climate change is exactly the same story repeating itself again! But Left is in a dilemma because such a way convincing people is archaic and irrational.

And they dug themselves this trap of using pseudo scientific arguments in trying to convince people, while turning their false truth as something that cannot be refuted!
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Aside: And now I see this...
"France, Italy, Germany defend Paris Accord, say cannot be renegotiated"
http://www.reuters.com/article/us-usa-climatechange-eu-idUSKBN18S6GNAgain, have these people completely turned into totalitarians when it comes to climate (much like saying "there is no more debating") that things cannot be renegotiated?? What if Trump's claims that US is unfairly constrained by Paris Accord are true? (which by the way nobody is mentioning here - Trump wants to renegotiate because the current deal is unfair. There is still a possibility for us to globally agree on something, on a more fair ground.) So because you signed a deal that gets biggest contributions from the biggest player and you are happy with it (same shit going on with NATO, btw), you are forever closed about renegotiating the deal? Well, that sounds very altruistic!