Ahhhhh rigggghhtttt....
Well natural activity has always existed, right from the start. Global warming is a natural process which existed way before humans even came into the picture....the Earth's atmosphere was pretty different to what it is now, due to things like volcanic eruptions etc....
Human activity has definitely caused an impact on the environment and may even have increased the problems for the environment since industrial revolution for example....
However, one must consider that a correlation between increased use of cars and transport and pollution etc may not have actually caused environmental problems....we do not know for sure if global warming and other environmental problems would stop if we all got rid of cars and stopped using electricity or whatever....as some of these processes have been a natural part of the Earth's cycle.
Look up some graphs on google about CO2 levels in the atmosphere and how they have changed or repeated over the centuries....
I very much doubt there is a clear cut answer to your qs lol
Hope it helps