Global warming is happening, but not because of human causes. I am not saying we do not have an impact on environment. However, global warming is not caused by humans.
During the sixties people and environmentalists used to say global temperature would drop dramatically, due to human causes (pollution, deforestation, etc.) And yet, the temperature did not drop.
Weather changes are only partially predictable. And global weather is definitely not predictable.
As to if "we can carry on any way we please with no consequences because nature will heal itself?" I think we can't do it. But the question has nothing to do with global warming anyway.