Friday, 11th February 2005

Speaker: Professor Stefan Rahmstorf
Potsdam Institute for Climate Impact Research (PIK) Potsdam University, Germany

Monday 21st February,
4 p.m. - 5 p.m.
Rupert Myers Theatre, UNSW Please click here for further information

About the speaker:
Please click here for further details

Last year, the risk of abrupt climate changes has repeatedly made newspaper
headlines. In February, a Pentagon study investigating the possible
consequences of an abrupt change in Atlantic ocean currents became public.
In May, the Hollywood thriller "The Day After Tomorrow" hit
movie theatres world-wide, based on a very similar scenario. What is the
scientific background of such scenarios, and where is the line separating
facts from fiction?

Data from the Greenland ice cores and deep sea sediments reveal that large
and abrupt climate changes (within ~10 years) have occurred frequently in
the past. In the absence of abrupt climate forcing, this suggests a highly
non-linear response of the climate system to gradual forcing. Does this
mean that abrupt climate changes could happen again in future as a result
of anthropogenic warming, or can they only occur under glacial conditions?

The talk attempts to summarise our current knowledge of the causes and
mechanisms of abrupt climate changes. It will discuss possible scenarios of
future non-linear climate responses such as changes in ocean circulation.
To evaluate the risk of such "low probability - high impact" events, a risk
assessment approach is needed.