Why an ethic of species?
Humanity’s relationship to other species has reached critical junctures. We are causing species to go extinct at an unprecedented rate in comparison with any other time in the last 65 million years. The background or normal historical rate of extinctions is approximately one species per one million per year. There is no precise data, and estimates vary, but many leading experts on biodiversity believe there are around ten million eukaryotic (or plant and animal) species. Therefore, in normal times, there would be around ten species extinctions per year. However, as a result of human activity – for example, pollution, extraction, and habitat destruction – species extinctions already exceed one thousand species per million per year. Moreover, the rate of extinction is expected to substantially increase due to global climate change, according to several scenarios surpassing 10,000 species extinctions per million per year, over a quarter of species committed to extinction by 2050, and one half of species extinct by 2100. Even on optimistic (and increasingly unlikely) scenarios, in which the increase in the global mean surface air temperature of the planet is limited to around 2°C above pre-industrial temperatures, 20–30 percent of species are expected to be at increased risk of extinction by 2100. The Earth’s next major extinction event appears to have begun, and this time it is anthropogenic.
In addition to eliminating species, we are engineering them in unprecedented ways. Intentional manipulation of species has been occurring since at least the beginning of agriculture – through selective breeding, hybridization, and grafting – and recombinant DNA techniques have been used for decades to insert genes from one individual into another, including across species. However, advances in genetic engineering have substantially scaled up the precision, intensity, and comprehensiveness of these modifications.