There are some thinkers out there throwing around the idea of creating a pill or a patch that would make meat-eating a thing of the past.... by inducing nausea. They believe that this would help reduce greenhouse gasses.
Here, let me throw a quote up here:
"Question: One human engineering strategy you mention is a kind of pharmacologically induced meat intolerance. You suggest that humans could be given meat alongside a medication that triggers extreme nausea, which would then cause a long-lasting aversion to meat eating. Why is it that you expect this could have such a dramatic impact on climate change?
Liao: There is a widely cited U.N. Food and Agricultural Organization report that estimates that 18% of the world's greenhouse gas emissions and CO2 equivalents come from livestock farming, which is actually a much higher share than from transportation. More recently it's been suggested that livestock farming accounts for as much as 51% of the world's greenhouse gas emissions. And then there are estimates that as much as 9% of human emissions occur as a result of deforestation for the expansion of pastures for livestock. And that doesn't even to take into account the emissions that arise from manure, or from the livestock directly. Since a large portion of these cows and other grazing animals are raised for consumption, it seems obvious that reducing the consumption of these meats could have considerable environmental benefits.
Even a minor 21% to 24% reduction in the consumption of these kinds of meats could result in the same reduction in emissions as the total localization of food production, which would mean reducing "food miles" to zero. And, I think it's important to note that it wouldn't necessarily need to be a pill. We have also toyed around with the idea of a patch that might stimulate the immune system to reject common bovine proteins, which could lead to a similar kind of lasting aversion to meat products."