One thing that being a scientist has taught me is that you can never be certain about anything. You never know the truth. You can only approach it and hope to get a bit nearer to it each time. You iterate towards the truth. You don't know it.
James LovelockIf you start any large theory, such as quantum mechanics, plate tectonics, evolution, it takes about 40 years for mainstream science to come around. Gaia has been going for only 30 years or so.
James LovelockThe 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.
James Lovelock