It speaks to the laziness, cowardice and myopia of the debate that you can't even whisper the plain and obvious upstream problem, human overpopulation, without being immediately shut down. The two political extremes will accuse you of being either a baby killer or a fascist endorsing genocide if you so much as whisper human population as a variable in environmental destruction.
The refusal to confront human population further originates with a fundamental psychological rejection of any perceived menace to the ego. That is, people hold their own personal selves as some kind of ultimate, supreme value and by extension reject any challenge to limitless human population growth. This is quite a crude, flawed, incorrect and simple-minded way to conceptualize the world and humanity, but it runs deep.
We've even extended this subconscious notion to some of our material things. Two or three decades ago, there was quite a lot of alarm about destruction of wildlife habitat and open space as consequences of urban sprawl. But now you can hardly mention this issue because of a perceived threat to human dwellings and by extension humans in general along with the individual ego. The same goes for agriculture. In the US alone, millions of acres of wildlife habitat and elbow room for people are degraded or destroyed every year by development and agricultural intensification. Yet this is completely ignored by media and policymakers. Even professionals who work in conservation are timid to discuss habitat destruction out loud. Human conversion of land to farms and cities is just taken as an inevitability or inviolable right, even while numerous options for better use of land area exist....