Is Global Warming Caused by Humans?

All greenhouse gases are invaluable to humans as they warm the earth so that we can live on it. Humans have burnt too many fossil fuels which add too many greenhouse gases into the atmosphere- warming the earth up. The cause of global warming is mainly humans putting too many greenhouse gases into the air and destroying the ozone.

in some way we are respond for the global warming, like frezon in the fridge that we use or ac or anything with frezon in it suppose to be harmful to the ozone too, and there is other things that use by us human, we need to walk more or bike or do other things instan of driving.

There is evidence to suggest that even if humans are not primarily responsible for global warming, that we have something to do with greenhouse gas emissions. Let me explain what I mean: http://www.blogfeast.net/djbtol/time_to_limit_emissions

i think maybe the answer is yes.But not all of this condition caused by human.

To be honest, yes. global warming is partially caused by man due to man made factories and materials that we use restore and build. I do happen to think that its partially apart of nature somethings cn be exlaned while others cant. For instance. Glaciers and the isthumus that once existed between America and Alaska...

I think it contributes to Global Warming, whilst not necessarily causing it. The world's climate is a chaotic system and is pretty good at surviving the variations that nature throws at it - things like variations in the output of the sun, dust and gases in the atmosphere from volcanoes and forest fires, etc. - but we might end up being the straw that broke the camel's back, so to say. One thing - AFAIK combustion of fossil fuels doen't generate CFCs. These gasses are man-made refrigerants that got in to the atmosphere over the years from old fridges, leaks, etc. and reacted with high level Ozone to deplete the Ozone layer. What fossil fuels do generate is Carbon Dioxide when they burn, and also sulphur compounds - oddly enough the suphur compounds can have a slight cooling effect on teh environment, but not enough to counteract the warming. And as the sulphur compounds generate acid rain, we've tended to try and get shut of them. Methane is another greenhouse gas, mostly generated by natural processes.