Is global warming the biggest threat to us or not. The debate seems to sway back and forth depending on who you happen to be listening to at the time. So, who should you believe? Read the following and decide for yourself.

Global warming - at least the modern nightmare vision - is a myth. I am sure of it and so are a growing number of scientists. But what is really worrying is that the world's politicians and policy makers are not. - Professor David Bellamy

We simply must do everything we can in our power to slow down global warming before it is too late... The science is clear. The global warming debate is over. - Arnold Schwarzenegger

Man has reached the point where his impact on the climate can be as significant as nature's. - Warrick, Joby.

The only people who would be hurt by abandoning the Kyoto Protocol would be several thousand people who make a living attending conferences on global warming - Professor Kirill Kondratyev, Russian Academy of Sciences

Global warming is indeed a scam, perpetrated by scientists with vested interests, but in need of crash courses in geology, logic and the philosophy of science. - Dr Martin Keeley

Global warming is not a conqueror to kneel before - but a challenge to rise to. A challenge we must rise to. - Joe Lieberman

While human-induced global warming is not going to turn present-day Earth into present-day Mars, global warming is dire enough that our most distinguished scientists recently concluded that as many as 1 million species on the planet could be extinct by 2050 if affairs do not change. - Jay Inslee

Unless we stop dumping 70 million tons of global warming pollution into the atmosphere every 24 hours, which we are doing right now the continued acceleration of this pollution would destroy the future of human civilization. - Al Gore

Greenhouse gases are a class of gases that can trap heat near Earth's surface. As they increase in the atmosphere, the extra heat they trap leads to global warming. This warming in turn places pressure on Earth's climate system and can lead to climate change. - Tim Flannery

The United States has a duty not to put obstacles in the way of the fight against global warming, but on the contrary to take the lead in this fight, because what is at stake is the fate of humanity as a whole. France will make this battle its primary battle - Nicolas Sarkozy

Our climate is warming at a faster rate than ever before recorded. - NOAA Administrator D. James Baker

There is a significant minority of genuine experts in the field who believe that the Armageddon scenario is grossly oversold, especially by climatologists in pursuit of government funding and research grants. Such dissidents are treated as if they were heretics within an established religion. - Dominic Lawson