Why? Three possible reasons. First, the Brave New World Factor: Research cloning gives man too much power for evil. Second, the Slippery Slope: The habit of embryonic violation is in and of itself dangerous. Violate the blastocyst today and every day, and the practice will inure you to violating the fetus or even the infant tomorrow. Third, Manufacture: The very act of creating embryos for the sole purpose of exploiting and then destroying them will ultimately predispose us to a ruthless utilitarianism about human life itself.
Human cloning violates the precautionary principle
A foundation of environmentalism, the precautionary principle requires that people must consider the consequences of their actions before they carry them out. The genetic engineering field is infamous for some of the unintended and unforeseen effects of genetic modification, such as the Bt corn’s harmful effects on the Monarch butterfly.
Can you give a reference for discussion of speculative risks?
Here, for example:
All of these are speculative.
And here: