I'd say we are making big breakthroughs in technology that will make greenhouse gas machines obsolete, and that's where we'll get eventually. But getting there

I'd say we are making big breakthroughs in technology that will make greenhouse gas machines obsolete, and that's where we'll get eventually. But getting there will take decades, because we have to obsolete out (and/or buy out) existing fossil-dependent infrastructure - heating in cold climates, and international shipping are two big ones that come to mind. But do what we can. That said, I'm not convinced this is going to lead to a global population reduction. In modernized economies, food isn't the boundary on population growth (all modern economies are at near-zero growth or even negative growth, and developing nations are modernizing to low birth rates at an astounding pace). Barring any huge changes, we're looking at the global population growing maybe 50% over the next century, and being completely level or shrinking after that, and most of that growth happening in the next few decades. So for the population to shrink significantly, it would require billions to die, of famine or resource wars. So what's going to shrink the food supply that much? Enough to induce famine at a global scale? Keep in mind that global warming moves more slowly than harvest cycles. Farmers and nations can make decisions on what crops to plant and adjust their farming practices based on new information and reasonable predictions. Next year's weather won't be much different than this year's was, even if it will be significantly different than the weather in 20 years. We are also on the cusp of two massive technological changes that will impact our farming abilities - IoT, and GMO. IoT allows plant-by-plant management of crops, reducing tilling and chemical use. GMO allows adaptation of crops to growing conditions more quickly than hybridizing does. It just seems to me that the concerns about feeding everyone, in the wake of a previous century that absorbed a quadrupling of the population while making more food than ever and a future of at least two key technological breakthroughs, is more doomsday than solid reasoning.