Section 4: Environmental Change

1. EGS 3021F: Vulnerability to Environmental Change Gina Ziervogel (gina@csag.uct.ac.za) December 2011 Section 4:Environmental Change This work by Gina Ziervogel is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

2. 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

3. 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)

4. What is global environmental change? • 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

5. www.metoffice.gov.uk/hadobs 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).

6. 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/)

7. 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

8. 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 Warming is unequivical? https://www.ipcc-wg1.unibe.ch/publications/wg1-ar4/ar4-wg1-ts.pdf IPCC WGI Fig TS.23

9. Cause of change https://www.ipcc-wg1.unibe.ch/publications/wg1-ar4/ar4-wg1-spm.pdf IPCC WGI Fig SPM.2

10. 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

11. IPCC Ar4, Ch 11 Rainfall(%)/Temperature changes by end of 21st Century https://www.ipcc-wg1.unibe.ch/publications/wg1-ar4/wg1-ar4.html

12. 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

13. Probably the single “largest threat to development and poverty alleviation” 10 International development agencies (Grid Arendal: http://maps.grida.no/go/graphic/climate_change_vulnerability_in_africa)

14. 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)

15. Climate change in South Africa

16. Temperature2030-2040 DJF JJA (CSAG, 2008)

17. Rainfall2030-2040 DJF JJA (CSAG, 2008)

18. Crop Suitability 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/

19. Aloe marlothii subsp. marlothiidistribution: current and potential future distribution (South African National Botanical Institute)

20. General message • 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

21. Specific impacts • Up to a 10% reduction in runoff water • 10% reduction in suitable cattle farming area • 10-20% reduction in suitable maize farming area • 38-55% reduction of the areas covered by the current biomass • Fire 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

22. 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

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

24. 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

25. 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)

26. 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

27. Acknowledgements Some slide material from: • Bruce Hewitson, Climate Systems Analysis Group (CSAG) • Coleen Vogel, Wits University • Tom Downing, Stockholm Environment Institute and GCAP