1. Working Group 2
Findings from AR4
Expectations from AR5
Chris Field
Vicente Barros
Co-chairs, IPCC WG2
8 December 2009

2. WG 2 – AR 4: Themes
• Vast stock of examples of observed changes
• Wide array of projected future impacts
– Magnitude varies with scenario
– Damages concentrated in extreme events
• Vulnerability exacerbated by other stresses
– Hot spots
– Vulnerable sectors and populations in all regions
• Many impacts can be avoided, reduced, or delayed by
mitigation
• Increased adaptation can help reduce future
vulnerability

3. Observed impacts
• Physical and biological systems
• 29,000 time series in chapter 1
• All continents and most oceans
• Likely that AGW has had a discernable influence
AR4, WG2, Fig 14.1

4. Changes in physical and biological systems, 1970-2004:
Statistical support for human influence.
AR4, WG2, Fig TS 1

5. Advanced detection-attribution techniques
to test link between species movements and AGW
AR4, WG2, Box TS 4

6. Responses to earlier springs
• Average advance in signs of
spring: 2.3 days/decade
– Budburst, flowering, nesting,
fledging, etc.
– 172 species (trees, shrubs,
herbs, butterflies, birds,
amphibians, fish
• Parmesan & Yohe 2003 Nature v 421
p 37
• Advancing bud-burst date:
– 2.5 days/decade
– 1900-1998
– Aspen in Edmonton
• Beaubien & Freedland. 2000. Int J.
Meteorol.

7. Impacts: links to specific levels of climate change
AR4, WG2, Table TS 3

8. Threats to water security
AR4, WG2, Fig TS 5

9. Regional threats: Australia and New Zealand
AR4, WG2, Fig TS 12

10. Avoiding impacts
with mitigation
AR4, WG2, Fig TS 4

11. mitigation Managing vulnerability with adaptation and mitigation
adaptation
AR4, WG2, Fig TS 19

12. WG2 in the AR5
• Common frameworks & currencies for impacts,
adaptation, and mitigation
• Broadening the range of assessed impacts
• The interaction of climate change & development
• Integrating climate science with climate impacts
• Assessing new impact studies based on AR5 climate
• Improving the treatment of regional aspects of
climate change

13. AR5: Broader range of assessed impacts

14. Ocean impacts
• Oceans
– half of global NPP
– 70% of surface area
– 41% has multiple
impacts
Behrenfeld et al Nature 2006

15. AR5:
Improved
treatment of
extremes and
disasters
AR4, WG2, Fig TS 13

16. AR5:
More thorough treatment of costs of climate change:
common framework & more inclusive currencies
IPCC 2007

17. IPCC AR5
• Move from “it’s real” to “here is the
information you need to make good decisions
for your stakeholders”
– Risk management framing
– Multiple stresses framing
– Full partnership for adaptation