I spend a lot of my time thinking about conservation and preservation, and I still don't know how I feel about them.
The words conservation and preservation are sometimes used interchangeably. They're in fact very different, and the difference is worth clarifying.
Preservation, in land-use terms, is the act of keeping a place pristine and completely unaffected by humans.
Conservation, on the other hand, accepts there will be an impact from humans, and it attempts to reduce the harm to a level where the resource will be renewable.
Both conservation and preservation are in favor of protecting, but preservation is like getting 100% on a test, and conservation is just passing. A perfect score might be too lofty of a goal for now.
UNESCO World Heritage Site, Ilulissat, Greenland
To truly commit to preservation mean's people can no longer enter wildlands, but it also means nothing we have made or moved can enter the environment either. With the global impacts of climate change, true preservation of any ecosystem is probably impossible (unless there are some crazy lava moles hanging out in the earth's core we don't know about).
If right now, you are thinking: "Climate change isn't human-caused." It is, but it is also very complex. The main problem is carbon which was trapped underground is now in the air. The Royal Society has tons of information about climate science, written in a way that is easy to understand. I encourage you to take a look. https://royalsociety.org/topics-policy/projects/climate-change-evidence-causes/basics-of-climate-change/
Humans are the most powerful species we know about, and we can have profound influences on the world, good and bad.
Back to the main topic.
Policies to preserve land would require halting all forms of mining, pollution, forestry, travel, farming, and pretty much everything we do. If we want to preserve the whole earth we better all move to the moon. So, the real question is: what the acceptable level of damage to the planet to appropriately conserve it?
I don't know the answer. I do know I have seen changes in the weather, wildlife, and landscapes of the places I regularly visit, in my short lifetime. So we probably are not doing enough. On a global scale, we need to reduce CO2 emissions, cut consumption, and all of the other things we hear about. It is hard to apply sweeping changes to day to day life, and I don't want to get into changing live now. Instead, let's talk about my favorite place, the backcountry.
Conserving natural areas like forests, deserts, waterways, etc. should strive to be as close to preservation as possible while allowing people to enjoy it within reason. (Just because the Joker wants to watch the world burn doesn't mean he should be able to start a forest fire.) Sometimes this means sacrificing an area to take the hit. Trails are a perfect example. They allow many people to explore a beautiful space while containing the environmental impact.
High Traffic Trail in Iceland
When there is no trail, it starts to be more of a balancing act. The impact of one person probably isn't a big deal, if a search party goes looking for them that's huge. The impact from ten people in a temperate forest might recover in a week, while the same ten in an arctic tundra could take hundreds of years literally.
A ton of research, including mine, shows how significant time outside can be for the people and the environments they visit, so I am not willing to stop outright.
I might be willing to put in a bit more effort getting closer to "preserving" the environment than many people, but I think everyone should reflect on the impact they are having on the world.
More information on minimizing your impact in the backcountry can be found at https://lnt.org/research-resources/