Scientists are being portrayed by much of the power structure in politics and business as having a vested interest - that they're just out to get more grant money by exaggerating the threats.
Scientists generally are really chicken about getting involved in some kind of dispute. As a broadcaster, I find it very difficult to urge them, if it is a controversial subject. They don't want to have science being portrayed badly.
Scientists and supercomputers have amplified our ability to look ahead. For decades, experts have warned us that human numbers, technology, hyper-consumption and a global economy are altering the chemical, geological, and biological properties of the biosphere.