> as apex predators we are extremely dependent on the lower branches of the foodchain working properly

Would you mind elaborating on this? It's not clear to me how we would be less dependent on lower branches of the food chain if we weren't apex predators.

The key is extremely. As an example, DDT sprayed to get rid of certain insects killed off a large number of birds at the top of the food chain, such trouble tends to concentrate. So poison the lower levels and the intermediate levels might survive but the apex species will suffer the most.

Oh, if you're referring to biological magnification then yes, but that's not the problem we're talking about, right? We're talking about global warming, which leads to species dying off (due to habitat loss, etc.) rather than staying alive but accumulating toxins... that's where I don't get how things would be any different if we were lower in the food chain?

We have many more points of dependency. So a malfunction in the machinery of life is more likely to be disastrous the further up the pyramid one lives. At the apex of the pyramid, we are dependent on the entire pyramid being structurally sound. And consider: we are already in the midst of the worst die-off of species since the dinosaurs. So the pyramid is already crumbling.

> We have many more points of dependency. So a malfunction in the machinery of life is more likely to be disastrous the further up the pyramid one lives.

You're just repeating the claim, and again, I do not follow the logic. Again, my question is: why would it be less disastrous if we were lower in the food chain? It would help to give an example of a species at a lower position in our food web and explain why, if we took its position, we'd be better off.

I'm not "just repeating the claim". If you're at the bottom of the pyramid, you only need sunlight and water. If half the animals die off, you're fine. The higher up you are, the more species below on which you are dependent. You're only dependent on what's below, not what's above. With us at the top, a 50% die-off would be catastrophic.

In that case I believe you're saying something else, not answering the question I had asked. The sentence I replied to was this:

> as apex predators we are extremely dependent on the lower branches of the foodchain working properly

Again, I repeat my question: if we were lower in the food web, wouldn't we still depend on branches of the food web lower than you? That seems to be true regardless of where you are on the food web. In fact, wouldn't we be more susceptible to harm if we had fewer possible sources of food? One would expect that the fewer alternatives we have, the worse off we would be, right?

It's the exact same effect but through a different path. Thinnk of it as a house, no matter where the house develops problems you'll always see it in the roof.

Not sure I understand the analogy. What classes of problems a house can develop structurally that are primarily visible standing on the roof, before the whole thing collapses? Or do you mean that even a partial collapse always affects things above it?

Any change in the structure of a house will typically affect the roofline. That's why checking the roofline is a very good thing to do when purchasing a house, if the roof is straight that is an important data point about walls and foundation supporting that roof. A sagging roof is a sure sign of problems in the rest of the building, rarely a sign of trouble with the roof itself.

I understand your logic about the house but I don't see why it is an apt analogy. It would help to explain what kinds of problems you are imagining for the house and what they could correspond to in the food web, both at the lower and upper levels.

Thanks! I'll remember that if I'll need to buy a house.

I posted the clip because it's a lighthearted argument about the reasons we're pursuing environmentalism.

I think a lot of current hysteria it is driven by petroleum politics and geopolitics. Otherwise, both parties in US government would have been pro-environmentalism. Try to think of why someone might have a different position given that they understand the science.

Finally, regarding humans surviving. What is the ultimate number of humans that should exist on earth? How much environmental damage or "change" is allowed to sustain these humans or for "progress" to occur? How many children should humans be allowed to have? Who gets to decide these things? Should humans be allowed to develop new industries at the expense of the environment?

Some people think that it's best to live in tribes and forego all technology. Some are content living with current tech advancement and keeping population at about what it is now. Others think humans should spread to as many planets as possible.

If you're not going to say anything, you could use fewer words to do so.