"A likely objection to my proposed long-term attempt to alleviate animal suffering is that it is very risky; the ecological system is too dangerous to tamper with. At our current levels of scientific and technological capabilities, I fully agree with this objection and do not advocate actions in the near future. However, this should not prevent us from aspiring to understanding more and hope to be able to help alleviate animal suffering in the future. Some people may believe that we should never think about tampering with the ecosystem, This may well suit the purpose of our lucky species which appears to enjoy positive welfare. But what if I am right that most other sentient species are suffering enormously? If and when we can confidently reduce their suffering enormously at a small cost and very small risk to ourselves, should we cautiously proceed to help them or should we postpone indefinitely? Analogously, if people in poor countries are suffering enormously from their poverty, and if people in the rich countries can help them develop out of their poverty at a very small risk of aggravating the global environment, should the help be extended? What if you were one of the suffering poor? What if we were one of the suffering species? Let us at least agree that more resources be put into the study of welfare biology."
January 1, 1970
https://en.wikiquote.org/wiki/Wild_animal_suffering