Post on 26-Mar-2015
Wie konnen (sollen) Wissenschaftler ihre
Ergebnisse verantworten gegenuber nicht-Wissenschaftler?
Case study: the Hockeystick
Nanne Weber (1989-1992 am MPI)
• A climate scientist is an authority. Some are better in communication than others • Communication=how can I explain science to a layperson• Big question= how do I deal with bad (stupid) journalists • Central point: wir haben recht
Communication – early 1990
IPCC FAR: Schematic diagrams of global temperature variations since the Pleistocene on three timescales (the last million yrs, the last 10,000 yrs and the last 1000 yrs)
The beginning – tentative
IPCC SAR: Decadal summer temperature index for the Northern Hemisphere (Bradley and Jones, 1993) based on 16 proxy records from N. America, Europe and E. Asia. Instrumental data are 50-yr smoothed.
The next step– growing confidence
IPCC TAR: Millennial NH temperature reconstruction for the warm season (purple, green) and annual mean (black; 2- error bars shaded) and annual instrumental data (red). All data are 40-yr smoothed
The finale– quantified! Error bars!!
Hockeyteam (2005)
The beginning
realclimate.org: ‘nearly a dozen proxy-based reconstructions by different groups show qualitatively similar behavior’ climateaudit.org: ‘they are all based on the same data’
Communication – 2006
Data overlap: 1000-yr long records
Site locs #records
Ref Where
Jones et al., ‘98 yes 4 Yes, but no
Mann et al., ‘99 yes (PCs: no)
9 and 3 PCs
Yes/no No/yes
Crowley&Lowery,‘00
no 15 yes no
Moberg et al., ‘05 yes 11 yes no
Esper et al., ‘02 no 5 no no
Briffa, ‘00 no ? no no
Site maps from Mann et al. (1998), Huang et al. (2000)
and Moberg et al. (2005)
Data overlap: the answer