As a result of the carbon-dioxide enrichment of the Earth's atmosphere, plants are now growing faster. Furthermore, global warming lengthens the growing season and increases net rainfall.

I grew up in the 1960s and wanted to become part of the great space exploration effort, but when I graduated from college in 1974, the Apollo program was over, and the country had moved into this pessimistic mode. We had entered the 'age of limits.'

People make their own fates, and if enough of us make our fate to be space explorers, perhaps we can actually get some space exploration done.

In what was called the second siege of Leningrad, thousands died, but Putin and his partners in crime got rich. Then Putin killed even more Russians when he had the FSB explode bombs in apartment buildings in Moscow in 1999 to give himself the pretext to seize dictatorial powers.

Humans want to know the hierarchy; it's important for there to be one leader.

Beginning under the Roman Empire, intellectual leadership in the West had been provided by Christianity. In the middle ages, who invented the first universities - in Paris, Oxford, Cambridge? The church.

Leaders are people who do the right thing; managers are people who do things right.

You have to keep on disrupting. If you let up the pressure, then al-Qaeda senior leadership will come back.