By "Some scientists", you the vast majority of scientists. Especially those that actually study the climate.I realise it's pointless my arguing with you, but I'll just point out that whilst there are some scientists who claim that human intervention is causing 'global warming', there are others who maintain that any climate changes are purely natural phenomena that have been occurring for millennia.
By "Other", you must mean those with a vested interest in denying it, such as the AAPG. Or those sponsered to say so, or just those that have invested too much into the wrong theory.
I have been very open minded on the subject over the years, but watching a number of debates on line, reading the IPCC reports, discussed it with others who work in environmental management (at conferences), watching deniers present their evidence, have all lead to the conclusion that AGW is real.
I have often played devils advocate in some debates and challenged the evidence, and each time I've come away more convinced.
No one denies that the climate changes naturally, but it is the rate of change that is un-natural. We know what impacts things like the sun and volcanoes have, so we can account for those, along with a whole host of others drivers.
I don't vote Green of course, as I care for the environment.