Presently we have carbon dioxide levels as high as they have been in the last 2 million to 5 million years. We understand that periodic shifts in the earth s orbital motion are such that we reached a peak in temperatures about 6000 years ago and a natural cooling trend started. Over the past 100 years, however, that trend has been turned around and has become a warming trend. The current high level of human activity has not necessarily been the cause of the onset of warming, however, human activity can exacerbate and accelerate natural warming. Even more important, if the naturally caused warming trend were to naturally begin to reverse, Ray states that increased human activity could be sufficient to seriously retard or even halt the reverse.
Carbon dioxide is a greenhouse gas.
It acts just like a giant glass window in the atmosphere, letting in sunlight, and reflecting back to the surface the longest wave solar radiation, infrared - namely, heat. Today most societies in the world have energy activities that are a small fraction of that of the United States and western Europe. With a rise in population to 10 billion in the next thirty years, and with much of this rise in parts of the world where economic activity will increase, the output of carbon dioxide will increase dramatically. Even skeptics agree with this and most of the major businesses in the world have conceded these facts. This is a harder problem and this is where Ray s current research enters.