Section 4:Environmental ChangeEGS 3021F: Vulnerability to Environmental Change Gina Ziervogel (gina@csag.uct.ac.za)December 2011

This work by Gina Ziervogel is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

Film: Wake Up, Freak Out - then Get a Grip is a short, animated film about climate change by Leo Murray.

http://wakeupfreakout.org/about.html

Film discussion:Note 2 aspects of each of the 3 components of vulnerability Exposure Sensitivity Resilience

Vulnerability in GEC context Understanding the nature of environmental

changes and how different groups are exposed in different ways (exposure)

Understanding how and why different systems and different groups/individuals are impacted differently by changes in the climate/environment (sensitivity)

Understanding how people respond to the changes, with a focus on the capacity to adapt so the negative impacts are reduced (resilience)

Dominated by climate change Includes other large scale environmental

change such as land use change and land degradation

Human dimensions of GEC Links change in environment to social

processes Globalization, Poverty, Disease, Conflict

What is global environmental change?

Global mean surface temperatures have risen by 0.74°C ± 0.18°C from 1906-2005. The rate of warming over the last 50 years is almost double that over the last 100 years (0.13°C ±0.03°C vs. 0.07°C ±0.02°C per decade).

www.metoffice.gov.uk/hadobs

The IPCC (Intergovernmental Panel on Climate Change) fourth Assessment Report (AR4)

Hundreds of scientific expert reviewers

Hundreds of authors from various countries

More than 620 expert reviewers (e.g. WG1)

A large number of government reviewers

6 years, WG Chapters, Technical Summaries, Summaries for Policy Makers Unanimous approval at plenaries for all Working Groups in 2007

(http://www.ipcc.ch/)

IPCC 1990 – The unequivocal detection of

the enhanced greenhouse effect is not likely for a decade or more

1995 – The balance of evidence suggests a discernible influence of human activity on the climate

2001 – New & stronger evidence that most warming observed over last 50 years is attributable to human activities

IPCC 2007:Most (>50%) of observed increase in globally averaged temperatures since the mid-20th century is very likely (conf. >90%) d.t. observed increase in anthropogenic greenhouse gas concentrations

Figure TS.23

IPCC WGI Fig TS.23

Warming is unequivical?

https://www.ipcc-wg1.unibe.ch/publications/wg1-ar4/ar4-wg1-ts.pdf

Cause of change

IPCC WGI Fig SPM.2

https://www.ipcc-wg1.unibe.ch/publications/wg1-ar4/ar4-wg1-spm.pdf

Working groups (AR4)University of Cape Town representatives

WGI – Climate Science Prof. Bruce Hewitson (Regional modelling)

WGII – Vulnerability, impacts and adaptation Dr. Guy Midgley (Biodiversity) Prof. Coleen Vogel (Africa)

WGIII – Mitigation Prof. Harald Winkler

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https://www.ipcc-wg1.unibe.ch/publications/wg1-ar4/wg1-ar4.html

Africa most vulnerable Most at risk because of low adaptive capacity,

multiple stressors Aggregate global damage costs (~1-5% of GDP

for 4deg warming) masks high costs in Africa Communities with high exposure, high sensitivity

and low adaptive capacity suffer great damages Sustainable development can reduce

vulnerability but climate change can impede achievement of sustainable development goals(IPCC 2007)

https://www.ipcc-wg1.unibe.ch/publications/wg1-ar4/wg1-ar4.html

(Grid Arendal: http://maps.grida.no/go/graphic/climate_change_vulnerability_in_africa)

Probably the single “largest threat to development and poverty alleviation”

10 International development agencies

Climate Change and Africa: IPCC AR4 By 2020

75-250 million people projected to be exposed to increased water stress due to climate change

in some countries, yields from rain-fed agriculture could be reduced by up to 50%.

By 2080 an increase of 5 to 8% of arid and semi-arid land in Africa

is projected under a range of climate scenarios Towards the end of the 21st century, projected

sea level rise will affect low-lying coastal areas with large populations.

Threat of disease such as malaria, sleeping sickness and dengue-fever. More study required.

(http://www.ipcc-wg2.gov/AR4/website/09.pdf)

Climate change in South Africa

Temperature2030-2040

DJF

JJA

(CSAG, 2008)

Rainfall2030-2040

DJF

JJA

(CSAG, 2008)

Crop Suitabilit

y changes

(Schulze, R. E. 2010. Atlas of Climate Change & the South African Agriculture Sector: A 2010 Perspective).

Access atlas at http://www.daff.gov.za/

(South African National Botanical Institute)

Aloe marlothii subsp. marlothii distribution: current and potential future distribution

                                                            

Warming all round Winter rainfall region drying Increases in late summer rainfall in

the E Higher evaporation Increased frequency of extremely

hot days Changes to climate variability

General message

Up to a 10% reduction in runoff water 10% reduction in suitable cattle farming

area10-20% reduction in suitable maize farming

area38-55% reduction of the areas covered by

the current biomassFire intensity increased by 10% Existing terrestrial biomes could shrink by

40% 44% of plant and 80% of animal species

would undergo a significant alteration to their geographic ranges

Specific impacts

Increased pests and invasive plants and health problems due to vector borne diseases

Changes in the suitability of land for different types of crops and pasture

Conversion of grassland to shrubland and invasion by alien plants and other organisms

Loss of arable land due to increased aridity and associated salinity, groundwater depletion and the rise in sea level

Changes in the distribution of good quality water for crop, livestock and inland fish production

Specific impacts

Buzz group

Given the expected biophysical impacts of climate change, what do you think the impacts will be on South Africa’s people

Science supports evidence of global warming Scientists from around the world Supported by government

Associated impacts being felt Africa particularly vulnerable

We can ADAPT to this change

Supporting adaptation

Adaptation is understood to be an adjustment in the ecological, social or economic systems in response to observed or expected changes and their effects and impacts in order to alleviate adverse impacts or take advantage of new opportunities

(Adger et al, 2005)

References Adger, N.W., Arnell, N.W. and Tompkins, E.L. 2005. Successful

adaptation to climate change across scales. Global Environmental Change, 15, pp. 77-86

Intergovernmental Panel of Climate Change (IPCC), 2007. Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K.B., Tignor, M. and Miller H.L. (Eds), Contribution of Working Group I to the Fourth Assessment Report, Cambridge, United Kingdom and New York, USA: Cambridge University Press.  (accessed at http://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html)

All web links were checked in November 2011

Acknowledgements

Some slide material from: Bruce Hewitson, Climate Systems Analysis

Group (CSAG) Coleen Vogel, Wits University Tom Downing, Stockholm Environment

Institute and GCAP