Colloquium “Searching the climate record for a human signal” 31 aug 2011
Climate scientists must communicate uncertainties and their consequences
Bart van den Hurk
(Involved in KNMI Climate Change Scenarios)
Colloquium “Searching the climate record for a human signal” 31 aug 2011
Climate scientists must communicate uncertainties and their consequences
Emphasised by antagonists of anthropogenic greenhouse
warming (AGW) theory
Emphasised by “alarmists”
Originate from• natural variability• imperfect models & knowledge• unknown future developments
Originate from• physical hazards• vulnerability of society• perception/political view
If there is uncertainty, there is risk
Colloquium “Searching the climate record for a human signal” 31 aug 2011
If there is uncertainty, there is risk
Average temperature change 2090-2100 relative to 1990
Pro
babili
tyuncertainty
0Cannot
be claimed
Defined as (politically)“relevant”
by e.g. Dutch Delta Committee
risk
Colloquium “Searching the climate record for a human signal” 31 aug 2011
Positioning KNMI’06 scenarios
Average temperature change 2090-2100 relative to 1990
Pro
babili
ty
0
G G+ WW+
Designed to explore possible future conditions
not presented as forecasts Supporting adaptation of society
to extreme conditions
relevance of different scenarios varies across applications
Colloquium “Searching the climate record for a human signal” 31 aug 2011
ConcludingUncertainties and risks are connected
Ignoring possibility of AGW or alarmist exaggerating implies strong scientific bias and not in the spirit of KNAW code of conduct
Making future explorations is relevant. Scenarios are useful tools for this