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Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change

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Page 1: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Climate Change: Impacts and Responses

Topic 6:Impacts of Climate Change

Page 2: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Why be concerned about climate change impacts?

What impacts have been observed to date?

What impacts are likely in the future?

Summary

Topic outline

UN image, Logan Abassi

Page 3: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Learning outcomes for this topic

Demonstrate an understanding of the major risks arising from climate change

Discuss observed climate impacts to date

Name projected impacts for a range of environments and sectors

Demonstrate an understanding of why attribution of observed impacts can be problematic

Demonstrate and understanding of why uncertainty exists over impact projections

Discuss possible regional impacts for Africa

Page 4: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Section 1:Why be concerned about climate change impacts?

Page 5: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Risks to unique and threatened systems

Risks from extreme climate events

Unfair distribution of climate impacts

Increasingly negative impacts with higher mean temperatures

Risks from large-scale discontinuities

Outline:Why be concerned about climate impacts?

Page 6: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Risk The potential for consequences where

something of human value (including humans themselves) is at stake and where the outcome is uncertain. Risk is often represented as probability of occurrence of hazardous events or trends multiplied by the consequences if these events occur.

Definition of risk

IPCC AR5 WGII, 2014 - Glossary

Page 7: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Risks to unique and threatened systems

e.g. Reptiles and amphibians are moving upslope in Tsaratanana Massif (Madagascar)

Calumma tsaratananensis,. credit: American Museum of Natural HistoryRaxworthy et al., 2008

Page 8: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Risks from extreme climate events

Woman in the Sahel terracing the soil to control for erosion.UN Photo/John Isaac

e.g. in Africa - reduced crop productivity associated with heat and drought stress

Page 9: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Unfair distribution of impacts

Image: FAO

e.g. productivity losses will occur in areas already at temperature maximum

Page 10: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

As temperatures rise further, aggregate impacts become increasingly negative everywhere

Image: NRC

Page 11: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Risks from future large scale discontinuities

Image: NASA

Page 12: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Risks of climate related impacts

IPCC AR5 WGII, 2014, FigTS-1

Page 13: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Section 2:Observed impacts

Page 14: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Observed global impacts

Snow, ice and frozen ground

Hydrological systems

Terrestrial biological systems

Marine and freshwater systems

Human systems

Outline:Observed impacts

Page 15: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

1

Observed global impacts

IPCC 2014 SPM2 WGII

Page 16: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Snow, ice and frozen ground

All images: NASAColumbia Glacier, Alaska

Muir Glacier, Alaska

Iceberg separating from Pine Island Glacier, Antarctica

Shrinking mountain glaciers

Declining Arctic sea ice cover

Declining areas of frozen ground in summer

Reduced snow cover in NH winter

Increasing freshwater release to ocean

Page 17: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Trends in rainfall are complicated

Temperature trends are impacting large lakes

Hydrological systems

Image: NASA

Image: IPCC 2007

Lake Tanganyika from space Historical and recent measurements from Lake Tanganyika

Page 18: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Plant and animal species are likely to respond to climate change in various ways.

Responses may include changes to:

• Timing of life cycle events

• Boundaries of inhabited ranges

• Population density

• Morphology

• Local or global extinction.

Terrestrial biological systems

Creative commons

Image: A. Barra

Page 19: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

13

Marine and freshwater biological systems

IPCC 2014 WGII Fig 6.8

Page 20: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Human and managed systems

IPCC WGII 2014 (adapted from Fig 7-2)

Page 21: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Section 3:Future climate impacts

Page 22: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Future climate-related risks

Future sectorial risks:

• Freshwater resources

• Marine systems

• Food production systems and food security

• Terrestrial ecosystems

• Coastal and low-lying areas

• Global economic impacts

• Human health

• Human security

Regional impacts: Africa

Outline:Future climate impacts

Page 23: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Risks of climate change

IPCC AR5 WG II 2014; Box TS5, Fig1

Page 24: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Freshwater resources

IPCC WGII 2014,Fig 3.4

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Marine systems

IPCC AR5 WGII 2014, Fig6-14

Page 26: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Summary of projected changes in crop yields, due to climate change over the 21st century. The figure includes projections for different emission scenarios, for tropical and temperate regions, and for adaptation and no-adaptation cases combined.

Food production system and food security

2010-2029 2030-2049 2050-2069 2070-2089

20

40

60

80

100

PER

CEN

TAG

E O

FYIE

LD P

RO

JEC

TIO

NS

02090-2109

0 – -5%

-5 – -10%

-10 – -25%

-25 – -50%

-50 – -100%

50 – 100%

25 – 50%

10 – 25%

5 – 10%

0 – 5%

Range of Yield Change

Increasein Yield

Decreasein Yield

IPCC AR5, 2014 WGII, Fig 7.-5

Page 27: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Terrestrial ecosystems

Soil erosion and deforestation – Guatemala; UN Photo/John Olsson

Page 28: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Coastal and low-lying areas

UN Photo/Logan Abassi

Page 29: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Global economic impact

UN Photo/Kibae Park

Page 30: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Human health

UN Photo/John Isaac

Page 31: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Human security

IPCC AR5 2014 WGII, Fig 12-3

Page 32: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Far-reaching impacts in human and natural systems

Predominantly negative impacts, especially if global mean temperature increase exceeds 2°C

Impacts likely to alter ecosystems

Floods and droughts likely to increase, with increasing risks of water pollution and incidence of water-related diseases

Coastal areas likely to suffer erosion, flooding, salt-water intrusion

Negative health impacts could occur, especially heat-related deaths, malnutrition and transmission of some diseases

Summary of projected impacts

Page 33: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Africa: key risks from climate change

IPCC AR5 2014, WGII, Chapter 22

Page 34: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Observed warming trend higher than the global average

Rainfall highly variable across Africa:

• West Africa has seen a decline

• Increase along Guinean coast

• No long term trends in precipitation in the rest of Africa

Increased rainfall inter-annual variability

Africa observed impacts

Page 35: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Mean temperature increase will exceed 2°C by mid to end of this century.

Precipitation projections more uncertain

Shifts in ecosystems

Water stress

Food security

Africa projected impacts

Page 36: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

Reasons for concern about impacts include: damage to ecosystems, extreme weather events, unfair impacts distribution, sudden abrupt climate change.

Observed impacts to date include changes to glaciers, crops and ecosystems on land, in freshwater and oceans.

Future impacts are potentially far-reaching. Impacts are likely but projections are inevitably uncertain.

Summary

Page 37: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

IPCC (2007). Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment. Report of the Intergovernmental Panel on Climate Change, [M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden, C.E.Hanson, (eds)]. Cambridge University Press, Cambridge, UK, 976pp

IPCC (2014). Climate Change 2014: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fifth Assessment. Report of the Intergovernmental Panel on Climate Change, [Barros, V.R., C.B. Field, D.J. Dokken, M.D. Mastrandrea, K.J. Mach, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L.L. White (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA

Raxworthy et al., (2008). Extinction vulnerability of tropical montane endemism from warming and upslope displacement: a preliminary appraisal for the highest massif in Madagascar. Global Change Biology (2008) 14, 1703–1720. OnlineOpen: This article is available free online at www.blackwell-synergy.com

 

References

Page 38: Climate Change: Impacts and Responses Topic 6: Impacts of Climate Change topic 6 – Impacts of climate change

End of Topic 6:Impacts of Climate Change

Next Topic: Adaptation