We achieve an astonishing fusion reaction output of 30:1 output to input, named BARY (after the center of the mass of -say- the solar system: barycenter). A magnificent result, celebrated across the world. They key was scale and also fusing heavier atoms. Rather than just H+H -> He, you also react, H + He -> Li!
(2 years later) After the celebrations are extinguished, we start to take advantage of the cheap energy. Sweden announces a new policy: free transport for all citizens. Amazon shipping is now free to all countries (except Iran…)! Fiji announces its bold foray into the space race. Most products witness a substantial drop in their prices.
(20 years later) A report is written on environmental impact of BARY. Li may pollute our atmosphere. Lithium is highly reactive and if released in sufficient quantities it could significantly alter the amount of oxygen in the atmosphere.
(30 years later) The new norm is cheap energy. Young thrill-seekers swap their automotive rides for miniaturized spacecraft. Movies and video games are rendered in 65536p (despite the fact we can’t tell the difference between 2048p and 4096p). People even take 1hr long showers (cos who does that now???)!
(50 years later) Oxygen levels are declining. And we are seeing the effects of it! Some marine biologists have noticed large populations of fish missing. Separately, entomologists are documenting a decline in ant populations! Some scientists link waste lithium from BARY to the reduction in oxygen levels, but according to others there is little consensus on the issue. The conclusion is that the climate is changing. But is it anthropogenic?
Same idiots, different physics.