The 20th century was the time when the world turned to use of fossil fuels and the 21st century will be the century of the renewables.

The biggest threat to global stability is the potential for food crises in poor countries to cause government collapse.

In today's integrated world economy, ... eradicating poverty may contribute as much to U.S. security as eradicating terrorism.

The 20th century was the time when the world turned to use of fossil fuels and the 21st century will be the century of the renewables.

It takes 1,000 tons of water to produce 1 ton of grain. As water becomes scarce and countries are forced to divert irrigation water to cities and industry, they will import more grain. As they do so, water scarcity will be transmitted across national borders via the grain trade. Aquifer depletion is a largely invisible threat, but that does not make it any less real.

The foundation is being laid for the emergence of both wind and solar cells as cornerstones of the new energy economy.

Another agricultural trend of growing concern is the increased nutrient content of coastal waters resulting from fertilizer runoff in agricultural regions. Augmented by urban sewage discharge in some situations, this results in huge algal blooms, which, as they die and decay, deplete the oxygen content in the water, leading to the death of the fish.