Semi-empirical estimation of the climate sensitivity

Torben Schmith

DMI

Strålingsbudget

Global Climate Modelling

Earth System Modelling

2xCO2 klimascenario

Feedbacks (selection)

• Boltzmann feedback (-)

• Water vapour feedback (+)

• Ice-albedo feedback (-)

• Cloud feedback (?)

Bestemmelse af klimasensitivitet

• IPCC: 2.1-4.4 K (for 2xCO2)– Global Climate Model studies– Paleo-studies (LGM, MCM)– Instrumental data (few studies only)

noiseTFdt

dTch ''

'

noiseFTT nnn ''' 1

122 xx QT

Energibalancemodel

Myhre et al. data

Myhre et al. data

ECHO-G

2.6 K (Roeckner et al. (1999)

• Cointegrated VAR approach– Model identification– Model estimation