I don't know what was the intention of the authors using the analogy of "genocide". But is a good analogy; it call to  "our better angels" to be responsible, to care, to empathize with the devastation affecting so many human beings. The sea level is rising, there are extreme weather events, drought in the west coast and southwest; fires in the west coast, on and on. Unusual high temperatures on the east coast and yes those wealthy enough can catch a flight to the Caribbean beaches but most American must work and endure. We must think about our children and grandchildren, not just ourselves and today​