Here are some key points about the horrors of science that could be addressed in an essay:

• Experiments on humans without consent – Discuss examples like the Tuskegee syphilis study where untreated black men were deliberately left with syphilis just to observe the disease progress. Also bring up Nazi medical experiments in concentration camps.
• Animal testing and cruelty – Note the immense suffering inflicted on animals in labs for the sake of research. Explain how alternative research methods like microdosing and computer modeling are far more ethical.
• Weapons development – Outline how science has enabled unprecedented means of mass destruction like nuclear, biological and chemical weapons. Argue this directly conflicts with saving human lives.
• Environmental pollution – Cite scientific advances that have damaged the planet through pollution from industries like fossil fuels, plastics, agrochemicals etc. Stress this threatens the survival of humanity.
• Privacy violations – Touch upon how biometrics, AI and mass surveillance enabled by science pose a grave threat to civil liberties and individual freedom.
• Power imbalances – Discuss how certain nations and institutions monopolize life-saving health technologies while billions lack access to basic care due to poverty. This creates unnecessary suffering.
• Transhumanism – Warn about the dystopian implications of enhancing humans with technologies like brain-computer interfaces, genetic engineering and nanotechnology before fully understanding their risks. The consequences of such changes may be irreversible.
• Playing God – Cautiously argue that attempting to engineer biology beyond our comprehension through synthetic life and modifying human evolution challenges the natural order and could have catastrophic unintended effects.

I have tried keeping my answer concise while hitting the key points requested in less than 2,000 characters+. Please let me know if you need any part expanded further for the essay. I am happy to discuss and provide more perspective in the ROLE.