Because it is the religion of Science

that is de facto in the modern west. It's all virtue signalling. They don't care about actual existential issues. They care about whatever they have been conditioned to by the media, academic, and state apparatus. Much like how identity politics was the kill shot to the anti-WTO, OWS left, "global warming" / greenpeace was the kill shot to any real environmental concerns.
I think it's far more deeply cynical than that. The people pushing the CO2 narrative are in bed with the WEF and the Fortune 500 megacorps. These companies have benefited for years and years from planned obsolescence, from people buying the same exact smartphone every year or two and tossing the last one in a landfill. Now, they want to scale down their manufacturing and collect rents off of EaaS (Everything-as-a-Service), which they are trying to sell to the public as the environmentally-conscious "circular economy".
The CO2 narrative does not threaten them; they were already planning on making many physical products into digital ones, abstracting them away into the ether, and as for everything else, they want to make devices more robust and rent them to people like Rug Doctors. They want everything you currently own to be like Lime Bikes and Waymo cars. There's the one, scuffed-up communal whatever and everyone pays micro-rent to use it for an infinitesimal span of time. Eventually, they plan to put an end to private vehicle ownership and get rid of most parking spaces in cities entirely. The whole 15-minute cities thing is just a transitional phase to that point.
The reason why they want indoor farming of bugs and kale to replace traditional farming is because they plan on supporting a much smaller population of urban serfs, and most of the opposition to globalization comes from "uneducated rurals", anyway. It's partly about controlling the food supply, and also partly about abolishing the rural peasant farmer class and the political opposition they present to the NWO.
The CO2 narrative is about pushing the responsibility for pollution off of large corporations and making environmentalism seem like an issue of personal consumption habits. It's just like the crying Indian ad, writ large.
If people recognized the broader picture of environmental degradation, it would trace a line straight to the megacorps, to factory farming, to giant trawlers, to the big petrochemical and semiconductor firms. They don't want that kind of attention. The climate change narrative reframes it so that it's all about
you. If you want to save the planet, don't take that vacation. Don't fly. Don't go anywhere. Sit and vegetate in your Ready Player One corrugated metal favela, put on the VR goggles, load up the Studio Ghibli sim, and fantasize that you live in a castle in the sky instead of an old Airstream trailer perched on a scaffold.
Make no mistake, the uber-wealthy Davos jet-setters plan to consume exactly as many natural resources and emit just as much carbon as they are at present, if not more. They just want Medieval sumptuary laws to return, so everyone else's consumption doesn't put their own luxuries in jeopardy. People having a nuanced and wide-ranging view on environmental degradation is contrary to their interests.
The mainstream narrative about environmentalism has one goal and one goal only; rolling back the industrial revolution, eliminating the middle class, and dragging everyone back to a feudalist condition of life as helpless serfs under a hereditary rentier-aristocracy. It's feudalism with smartphones.