Many natural scientists such as physicists Murray Gell-Mann, William Shockley, and Andrei Sakharov have worried about human population size and growth. Yet, almost every measure of material and environmental human welfare in the United States and in the world shows improvement rather than -deterioration.
Fewer people die of famine than in earlier centuries.
The real prices of food and other raw materials, showing increased natural-resource availability rather than scarcity, began dropping rapidly in the last 200 years. The major air and water pollution in the advanced countries has been lessening rather than worsening, particularly in the last 40 years. Maximum transport speeds have zoomed upwards in the last 200 years, and in the mid-19th century, maximum message speeds went from 30 miles an hour to the speed of an electrical impulse. Income and wealth rose above subsistence for more than a small minority for the first time in human history, beginning 200 years ago. Many assert that these benign trends cannot continue indefinitely because of some physical limit.