“A review was published in Nature, very scathing, essentially calling me incompetent, though they didn't use that word. I am putting a reply on my Web site in a few days, where I go through their arguments, paragraph by paragraph.”

“Even if every major government were to slap huge taxes on carbon fuels - which is not going to happen - it wouldn't do much to halt climate change any time soon. What it would do is cost us hundreds of billions - if not trillions - of dollars, because alternative energy technologies are not yet ready to take up the slack.”

“Global warming is real - it is man-made and it is an important problem. But it is not the end of the world.”

“I tentatively believe in a god. I was brought up in a fairly religious home. I think the world is compatible with reincarnation, karma, all that stuff.”

“I think it's great that we have organisations like Greenpeace. In a pluralistic society, we want to have people who point out all the problems that the Earth could encounter. But we need to understand that they are not presenting a full and rounded view.”

“In the rich world, the environmental situation has improved dramatically. In the United States, the most important environmental indicator, particulate air pollution, has been cut by more than half since 1955, rivers and coastal waters have dramatically improved, and forests are increasing.”

“Listen, global warming is a real problem, but it' s not the end of the world. A 30-centimetre sea level rise is just not going to bring the world to a standstill, just like it didn't over the last 150 years.”

“Money spent on carbon cuts is money we can't use for effective investments in food aid, micronutrients, HIV/AIDS prevention, health and education infrastructure, and clean water and sanitation.”

“My suggestion is that we should first work to ensure the Third World has clean drinking water and sanitation.”

“Obviously any group that has to have funding also needs to get attention to their issues.”

“On average, global warming is not going to harm the developing world.”

“So it's mainly a question of helping the Third World overcome the effects of global warming.”

“The Kyoto treaty has an estimated cost of between USUSD150 and USD350 billion a year, starting in 2010.”

“The main environmental challenge of the 21st century is poverty. When you don't know where your next meal is coming from, it's hard to consider the environment 100 years down the line.”

“The obvious issue is providing clean drinking water and sanitation to every single human being on earth at the cost of little more than one year of the Kyoto treaty.”

“The only thing that will really change global warming in the long run is if we radically increase the speed with which we get alternative technologies to deal with climate change.”

“The saddest fact of climate change - and the chief reason we should be concerned about finding a proper response - is that the countries it will hit hardest are already among the poorest and most long-suffering.”

“The second thing is, if you want to do something about global warming, you have to think much more long-term. There is something wrong with saying we should start using renewables now, while they are still incredibly expensive.”

“There is no doubt that we should take solar radiation into account. We have seen ground temperatures rising since 1975, and it is important to know to what extent that has been caused by the sun or by carbon dioxide.”

“There is no question that global warming will have a significant impact on already existing problems such as malaria, malnutrition, and water shortages. But this doesn't mean the best way to solve them is to cut carbon emissions.”

“Think on a 50-year scale, which is a much more natural time-scale for global warming. The US is right now spending about 200 million dollars annually on research into renewable energy.”

“To prepare adequately for the challenge of global warming, we must acknowledge both the good and the bad that it will bring. If our starting point is to prove that Armageddon is on its way, we will not consider all of the evidence, and will not identify the smartest policy choices.”

“We need to invest dramatically in green energy, making solar panels so cheap that everybody wants them. Nobody wanted to buy a computer in 1950, but once they got cheap, everyone bought them.”

“We worry about the seemingly ever-increasing number of natural catastrophes. Yet this is mainly a consequence of CNN - we see many more, but the number is roughly constant, and we manage to deal much better with them over time. Globally, the death rate from catastrophes has dropped about fifty-fold over the past century.”

“When thinking about the future, it is fashionable to be pessimistic. Yet the evidence unequivocally belies such pessimism. Over the past centuries, humanity's lot has improved dramatically - in the developed world, where it is rather obvious, but also in the developing world, where life expectancy has more than doubled in the past 100 years.”

“Wishful thinking is not sound public policy.”