Conditional on at least 10 million 18-24 year old biological humans living in liberal democracies and having some capacity to choose, will <10% of them consume farmed sentient beings on a weekly basis before 2100.
Conditionality
This is intended to eliminate scenarios in which humans are broadly unable to choose freely and whose consumption is driven out of necessity (e.g. for reasons such as catastrophe, social collapse, value lock in, autocratic rule/command economies).
This will be evaluated using some highly regarded index e.g.
https://en.wikipedia.org/wiki/The_Economist_Democracy_Index
If at any point these conditions are not met the market will resolve N/A, to avoid cases of societal collapse and subsequent recovery.
Choice
Individuals and societies must have some capacity (similar to the freedom they have in 2023) to determine their consumption behaviours else this will resolve N/A.
If individuals are unable to determine their consumption because society has restricted access to meat (e.g. banning consumption/animal farming) that would still represent a choice, provided they live in a liberal democracy and the market may still resolve Yes/No.
18-24 Age Group
This is intended to capture cohort replacement effects, it's possible if life expectancies are greatly increased in the near future a large fraction of the population in 2100 will be alive today and individual's behaviours may change more slowly than society.
The market intends to capture prevailing sentiment of the people of the transient generation, not broader society. This would be analogous to surveying sentiment towards homosexuality among Gen Z in 2023, which might be materially different to broader society.
Sentient beings
This is intended to represent commonly consumed farmed animals in 2023 (Cows, Pigs, Chickens) that are broadly believed to have subjective experience and capacity to suffer, allowing for drifts in genetics / consumer preferences.
This excludes lab grown meat as well as animals reared in an entirely unconscious state. It also excludes insects, bivalves and similar which might be contentious and form a relatively small part of 2023 diets.
Resolution
This market will resolve to N/A, if necessary conditions are not met at any point before 2100.
This market will resolve Yes if <10% choose to consume meat at any point before 2100.
This market will resolve No if by 2100 10% or more choose to consume meat and necessary conditions prevail throughout.
Disclaimer
I will not bet on this market and may modify conditionality in the spirit of the question (e.g. to address extinction, transhumanism and similar concerns) to remove confounding effects.
It is highly unlikely that fewer than 10% of 18-24 year olds will choose to eat meat by the year 2100. While dietary preferences and choices may evolve over time, a drastic shift of this magnitude within the next 80 years seems improbable based on historical trends and our current understanding of human dietary habits.
Meat has been in human diets for centuries, and cultural, economic, and nutritional factors have contributed to its widespread consumption. While there is a growing interest in alternative diets such as vegetarianism and veganism ( 350% increase of vegan people in the UK) it's important to note that these dietary choices are still a minority among the global population, and the adoption rate varies by region and culture. I believe the number can be very close to 10% however it won't be lower than that.