Those IPPC scientists are arguing again

This week, delegates from more than 140 countries and scientific experts on the Nobel Prize-winning Intergovernmental Panel on Climate Change are going line-by-line through a draft summary of the scientific understanding of climate change, and what can be done to slow the gradual warming of the Earth in Valencia, Spain.

The report is due to be released this Saturday.

There is conflict in the group, as there should be. Reports of individual scientists dissenting in their interpretation of the data and form of words are filtering out. But they have issued a statemet saying they are determined that their fourth report this year will not be watered down and exclude vital information under pressure from nations own domestic agendas, as has happened.

The scientists acknowledge their previous reports have been conservative and had a poor track record of predictions. Temperatures have risen faster than they have predicted.

The assessment reports are widely acknowledged as the most authoritative compilation of climate science available, largely because of the rigorous process of peer review.

But its thoroughness takes time and this means it lags behind the latest research - two or three years.

Sceptics will always say that environmental groups and lobbyist can't be trusted with the facts. But what about the two U.S. security institutes who issued a joint report this month - The Center for Strategic International Studies (co-chaired by an ex- chairman of the Armed Services Committee and the Permanent Subcommittee on Investigations) and the Center for a New American Security (President: former Senior Adviser at the Center for Strategic and International Studies)?

They compared predictions of climate change by the panel and other researchers in the last two decades with changes that actually occurred, and found the scientists had consistently fallen short.

Part of the reason was the lack of data, but also that the scientists shied away from controversy and wanted to avoid being discredited as "alarmists". That's left to the likes of WWF.

Next month governments meet in Bali, Indonesia, to start negotiating a successor to the Kyoto Protocol, using the IPCC's evidence.