We are sliding back into a dark era, and there seems little we can do about it. I am profoundly depressed at just how difficult it has become merely to get a realistic conversation started on issues such as climate change or genetically modified organisms.

We've gotten so good at growing food that we've gone, in a few generations, from nearly half of Americans living on farms to 2 percent. We no longer think about how the wonderful things in the grocery store got there, and we'd like to go back to what we think is a more natural way.

As people around the world become more affluent, they are demanding diets richer in animal protein, which will require ever more robust feed crop yields to sustain.

New molecular methods that add or modify genes can protect plants from diseases and pests and improve crops in ways that are both more environmentally benign and beyond the capability of older methods.

In agriculture, people have taken wild plants that can't be eaten by people - and turned them into wonderful food sources. And that's because genomes can change, and people working with plants have picked mutations. Mutations are nothing more than genetic changes.

In many places in the developed world, we eat or waste probably twice as many food calories as we really need. We're wasteful of food. We ship all over the world. We're now realizing that generating the energy to ship the food around the world is also ruining our climate.

One of the really remarkably beneficial aspects of genetic engineering is that much of the previous methodology for controlling pests and so forth is through chemicals that affect a very broad spectrum of insects, for example, or fungicides that control fungi.