How did your house and your neighbor's house get there in the first place? We cut down trees to make paper or more houses, poison the atmosphere with factories and cars, kill wildlife for stupid reasons, poison rivers, consume water, litter the land, and we take away our own resources.
Humankind is definitely dangerously harming the environment in many ways. They make factories which emit harmful chemicals. These chemicals cause acid rain, pollution and other things that harms the environment. Humans have done things to put a hole in the earth's ozone layer. The cars that humans drive are polluting the environment. These are only a small sampling of things humans have done to harm the environment.
The changes we have witnessed in such a small period of time do not happen naturally, humans have been abusing what the environment has for them for decades with a "somebody will fix this later" mentality and it's starting to catch up to us. The fact that there are actual real people that say global warming isn't happening is all you need to know about the chances we're going to reassess and improve how we do things.
In the 19 60s, they just dumped all their oil down in to the sewers. But now there are so menu laws trying to stop that and instead of dumping the oils they're reusing them. So that is why I am saying that we are much less dangerous to our environment.