"there wasn't much they could do to it"

This is not really true. Humans have been radically changing the environment from before they were even "Homo Sapiens".

For just one example, prehistoric human hunting had devastating effects on animal populations with most large mammals killed off by humans every time we moved into their habitat. We even have a couple of data points when this happened very quickly. In Australia around 50k before present (BP) and in the Americas around 10-15k BP. From this[1] Atlantic article).

"By looking at how mammals have changed in size over time, Smith and her colleagues have shown that whenever humans are around, the mammals that disappear tend to be 100 to 1000 times bigger than those that survive. This isn’t entirely new: Many scientists, Smith included, have found the same trends in Australia and the Americas. But the new analysis shows that this pattern occurred in every continent except Antarctica, and throughout at least the last 125,000 years."

And the abstract of the paper this article is writing about [2]

"Since the late Pleistocene, large-bodied mammals have been extirpated from much of Earth. Although all habitable continents once harbored giant mammals, the few remaining species are largely confined to Africa. This decline is coincident with the global expansion of hominins over the late Quaternary. Here, we quantify mammalian extinction selectivity, continental body size distributions, and taxonomic diversity over five time periods spanning the past 125,000 years and stretching approximately 200 years into the future. We demonstrate that size-selective extinction was already under way in the oldest interval and occurred on all continents, within all trophic modes, and across all time intervals. Moreover, the degree of selectivity was unprecedented in 65 million years of mammalian evolution. The distinctive selectivity signature implicates hominin activity as a primary driver of taxonomic losses and ecosystem homogenization. Because megafauna have a disproportionate influence on ecosystem structure and function, past and present body size downgrading is reshaping Earth’s biosphere."

Human started wild fires would be another.

Humans changing life on Earth is as old as humanity but the last few hundred years is the first time we have started to care at a societal/global level. National Parks were being form in the US starting in the early 1900's. Half of Alaska was preserved in the 1970's, many countries in Africa are doing the same. If those African countries can get rich enough, fast enough some of the great savanna ecosystem could be kept from extinction. As usual, a balance of going forward and preserving what we have will be the best bet for a good outcome. It does not seem that having radical groups of people holding opposing views works well to maintain this balance. Maybe each individual needs to see the value in change and stability for good things to happen more than bad. Moloch[1] is always with us but its power can be reduced from time to time.

[1]https://slatestarcodex.com/2014/07/30/meditations-on-moloch/

[1]https://www.theatlantic.com/science/archive/2018/04/in-a-few...

[2]http://science.sciencemag.org/content/360/6386/310