This is a conservative report. It could turn out to be worse than this. The US government is trying to play down GW.
“Global climate change is "very likely” to have a human cause, an influential group of scientists has concluded.
The Intergovernmental Panel on Climate Change (IPCC) said temperatures were probably going to increase by 1.8-4C (3.2-7.2F) by the end of the century.
It also projected that sea levels were most likely to rise by 28-43cm, and global warming was likely to influence the intensity of tropical storms.……………
Now, the panel concluded that it was at least 90% certain that human emissions of greenhouse gases rather than natural variations are warming the planet's surface……………
On sea level, there has been a more fundamental debate.
Computer models of climate do not generally include water coming into the oceans as ice caps melt. So the IPCC had to decide whether to exclude this from its calculations, or to estimate the effect of a process which scientists do not understand well but which could have a big impact.
They used the former, more conservative approach, projecting an average rise in sea levels globally of between 28 and 43cm. The 2001 report cited a range of nine to 88cm. “
http://news.bbc.co.uk/2/hi/science/nature/6321351.stm