WHILE the international community readies itself for gradual global warming over the next century, a growing number of scientists are beginning to worry that climate change might come much sooner - and be much more catastrophic - than previously thought. They point out that, in the past, climate change has not been gradual. Europe's climate has switched from arctic to tropical in three to five years and, they warn, it can happen again. Fred Pearce, of the New Scientist, has spent the past two years speaking to climate experts who are studying the possibility of "type 2" climate change -...