They all serve the left-wing effort to promote their political propaganda of climate change . It's a left-wing conspiracy ...
No, denying the climate change is the right wing conspiracy. The change is real. The majority of climate scientists and major research organizations agree on that. But hey, it's a free country - somewhat - so deny it all you want. The beauty of modern school education in the US is that it doesn't really provide a broad systematic knowledge and appreciation of scientific approach to solving complex problems, but it does greatly boost self esteem.
The problem is in defining just what's causing the global warming, what is the mechanism of change, and what can people do to slow it down or stop it.
I happen to believe that (1) there's much more at play than just human activity - although human activity definitely contributes to the issue (2) the mechanism is still poorly understood and requires much more research (3) no single country can make a difference alone,
and there will be no real concerted effort to do anything - China / Brazil / India / Indonesia / etc. will not put brakes on their developing economies, Canada and Russia actually stand to benefit from the warmer climate, and the US will not commit economic suicide alone. Europe will actually be doing something because they have a strong green lobby that has long ago pushed for stricter environmental regulations (so much of the money has already been spent and they are well ahead of most other countries) plus they don't really have that much manufacturing remaining, with exception of Germany and some parts of Eastern Europe. For them, forcing everyone else into stricter emission / energy consumption standards will be both doing the right thing and leveling the playing field by utilizing the advantage they already have. But I doubt that they would agree to drastically stricter standards than what they have today, either.
Plus, look at what we know of the climate... several Ice Ages that came and went without any human involvement, the warm spells in between, the Greenland that was actually green in the times of Eric the Red, then came the Little Ice Age around late Middle Ages / early Renaissance - too early for any human contribution; nature is a powerful force all by itself.