Global warming is happening. But to say that a human cause (anthropogenic) is "proven beyond all doubt" simply isn't true.
There is evidence that climate change is exhibiting an overall warming trend. There is ample evidence that this trend will have serious problems for humanity as well as other animals and plants on the planet.
The evidence for anthropogenic causes may simply be coincidental. There is a good correlation between CO2 emissions and overall warming, but there is also evidence that a warming climate as we continue to come out of the last 'ice age' is normal.
The crowd that says global warming is the fault of man may be jumping the gun; but the crowd that denies it is occurring is simply not looking at the evidence. Reality lies somewhere in the middle, with man as a very likely contributor to a trend that should be expected anyway.