Science always uses metaphor.

You mustn't take what I say as gospel because no one can second-guess the future.

One pound of uranium is worth about 3 million pounds worth of coal or oil.

The entire range of living matter on Earth from whales to viruses and from oaks to algae could be regarded as constituting a single living entity capable of maintaining the Earth's atmosphere to suit its overall needs and endowed with faculties and powers far beyond those of its constituent parts.

The big threat to the planet is people: there are too many, doing too well economically and burning too much oil.

The problem is we don't know what the climate is doing. We thought we knew 20 years ago. That led to some alarmist books - mine included - because it looked clear-cut, but it hasn't happened.

We are the intelligent elite among animal life on earth and whatever our mistakes, [Earth] needs us. This may seem an odd statement after all that I have said about the way 20th century humans became almost a planetary disease organism. But it has taken [Earth] 2.5 billion years to evolve an animal that can think and communicate its thoughts. If we become extinct she has little chance of evolving another.