Huw Griffiths Understanding global climate change through new breakthroughs in polar research...

Huw Griffiths

Understanding global climate change through new breakthroughs in polar research

hjg@bas.ac.uk

• Changes in sea-ice

• Rising water temperatures

• Ocean acidification

Response of polar marine ecosystems to climate change

Parkinson, 2002

Sea-ice change

declining

growing or stable

Colonies:

50% decrease in krill population

Atkinson et al 2004

1976 - 2003

Over 2-fold decrease / 10 years

Over 2-fold increase / 10 years

© I. Arndt, source: AWI

Bracegirdle, 2008

COPE or ADAPT

MOVE • deeper • further South

Meredith & King 2005

Ocean warming

EXTINCTION

+0.05°C / year

Cheung et al 2009

Changes in species composition - 2050

Sea Ice Zone: January

1991

1993

1998 2000

2001

2002

2003

2004

2005

2006

2007

2008

Stress: 0.05

Southern Ocean Continuous Plankton Recorder

65 mm

0.5 mm

Pre-2000:Pre-2000:large zooplankton (krill)large zooplankton (krill) Post-2000:Post-2000:

small zooplankton (small zooplankton (Oithona)Oithona)

Hosie, pers. com.

Increased CO2 ocean acidification (2100)

calcium carbonate

Orr et al., 2005

© I. Arndt, AWI

Photographs: J. Gutt/W. Dimmler, © AWI/Marum, Univ. Bremen & M. Scheidat, L. Lehnert; results: Gutt et al (submitted to DSR II)

• >8000 known species• 78% of species live on the sea floor• More than half are only known from the Antarctic

Climate Change and Benthic Animals

• Food availability

• Invading predators

• Icebergs

• Heat stress

• Acidification

• Species ranges

Range shifts: Where should we look?

Southern Limits Northern Limits

Barnes et al., 2009

Summary

• Sea-ice changes directly affect the Antarctic marine life

• Warming is expected to change species compositions: invasions, migrations

and extinctions

• Acidification a possible problem for pelagic and benthic species

• Shifts in species ranges will be the first indication of major changes affecting

the seafloor life

For more information about climate change in the Antarctic:“Antarctic Climate Change and the Environment (ACCE)”

www.scar.org

Acknowledgements

I would like to thank all those who helped in the making of

this talk.

Especially Julian Gutt, Graham Hosie, all those involved

in the SCAR climate change report and my colleagues at

the British Antarctic Survey.