climate change updated Corinne Le Quéré Professor of Climate Change Science and Policy University of East Anglia

Brohan et al. J. Geophys Res. (2006) temperature measurements on land

Photo: Xiaojun Yuan LDEO.columbia.edu Kent et al. (2010) Wires of Climate Change earthobservatory.nasa.gov temperature measurements in the sea

warming of global air temperature data source: NASA-GISS, reference period temperature anomaly (°C)Time (y)

melting of glaciers and ice caps Qori Kalis, Peru 1978, 2002

Kilimanjaro 1993, 2000 melting of glaciers and ice caps

Trift, Suisse 1948, 2002, 2006 melting of glaciers and ice caps

data source: Dyurgerov and Meier 2005, figure from Rober A. Rohde for the Global Warming Art project

Copenhagen Diagnosis 2009 melting of the Arctic sea ice

Warming of the climate system is unequivocal adapted from IPCC 2007, data from NASA GISS, NSIDC, Church and White, Colorado University sea level Arctic Sept ice extent temperature Time (y)

But is it caused by human activities? yes! 1.we understand the processes 2.global warming has fingerprints John Tyndalls laboratory setup 1859

IPCC 2007 Fig 9.5 Fingerprints for climate change: surface warming volcanoes & sun only observed

IPCC 2007 Fig 9.5 greenhouse gases, volcanoes & sun Fingerprints for climate change: surface warming observed volcanoes & sun only

But is it caused by human activities? yes! 1.we understand the processes 2.global warming has fingerprints 3.it is above the background natural variability (caveat) Copenhagen Diagnosis 2009, from Mann et al. 2008

But is it caused by human activities? yes! 1.we understand the processes 2.global warming has fingerprints 3.it is above the background natural variability (caveat) 4.there are no other reasonable explanations If it looks like a dog, and it barks like a dog, it is a dog.

my best guess (~2°C) (~2.5°C) (~3°C) (~4.5°C) today So whats next?

year of my retirement year of your retirement (~2°C) (~2.5°C) (~3°C) (~4.5°C) today So whats next?

melting of the ice (and other unknowns)

time (y) (billion) world population projections: Lutz et al. IIASA 2007 *

time (y) (billion) world population projections: Lutz et al. IIASA 2007 *

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