Take air quality in the United States today: It's about 30 percent better than it was 25 years ago, even though there are now more people driving more cars.

Lest those islands still seem to you too remote in space and time to be relevant to our modern societies, just think about the risks... of our increasing globalization and increasing worldwide economic interdependence.

The southward advance of native African farmers with Central African crops halted in Natal, beyond which Central African crops couldn't grow - with enormous consequences for the recent history of South Africa.

I've always been interested in a lot of things, and a lot of things at the same time, and I always tried to explain them to myself. I ask a lot of questions.

Today Charles Darwin is best known for establishing the fact of evolution and for recognizing the major role of natural selection in driving it.

Technology causes problems as well as solves problems. Nobody has figured out a way to ensure that, as of tomorrow, technology won't create problems. Technology simply means increased power, which is why we have the global problems we face today.

The King's 28 letters have been described by scholars as the world's best alphabet and the most scientific system of writing.