Man is wholly responsible for climate change in this day and age. Our use of greenhouse gases has punched a hole in the ozone layer protecting us from global warming. Since global warming is man-made, we need to fix this problem ourselves. The Earth can't regulate the change caused by us human beings at this point.
No, I do not believe that man is the only element that has brought about climate change. Before man existed there were changes in the making. For instance something brought about the extinction of dinosaurs and other prehistoric life forms. Granted, I believe that we have some fault in climate change, we are not the only reason behind the change.
I do not believe man is the only responsible party for climate change, while I'm sure we've nudged it along, we aren't in control. Climate change obviously happens on our planet without our influence, as we can tell of different Ice Ages and warm periods. Never the less, we've burned fossil fuels at accelerated rates and emitted a lot of green house gases, so it's foolish to assume we aren't making an impact at all.
Of course it is human activity that spews poisons into the air that is responsible for most climate change. But we are part of a larger eco system that is also undergoing transition all the time and so it is hard to separate it. Still, as responsible people we need to take charge of our own actions.
Man is not soley to blame for climate change. I believe that climate change would happen regardless of man. It is a natural parto of nature. I do think that man has greatly sped up the climate change process though. Man made a natural occurring thing happen much faster then it should.
Some people argue that global warming is not man-made at all, but most people do agree that man is contributing to it. That being said, there are other things that contribute to global warming. Among them, animals are methane-producing (though, it could be argued that people created the agricultural industry that has led to there being a lot of methane-producing livestock). Additionally, we must also acknowledge that climate change can be cyclical. There was a mini ice age as recently as Medieval times.
History has shown that there have been many climate changes that were not caused by human activity. There was the so called "Little Ice Age" in Europe in the Middle Ages that could not have been caused by carbon emissions. Although human activity may contribute to climate change, these changes also occurr naturally sometimes.