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One damn thing after another cascading global change

One damn thing after another cascading global change. Dr Bob Scholes CSIR Fellow UNISA College of Economic and Management Science 25 November 2009 . Have you noticed that everything seems to be going wrong at once?. Global financial crisis

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One damn thing after another cascading global change

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  1. One damn thing after anothercascading global change Dr Bob Scholes CSIR Fellow UNISA College of Economic and Management Science 25 November 2009

  2. Have you noticed that everything seems to be going wrong at once? • Global financial crisis • Peak oil, fuel price hikes, energy crisis in South Africa • Food price escalation, real hunger affecting nearly a fifth of the world’s population • Water shortages in many parts of the world • The sixth extinction crisis…. What is going on??? © CSIR 2009 www.csir.co.za

  3. 1. A globally-connected world • Non-human factors • Orbital forcing • Solar activity • Tectonics etc • Biogeochemical change • Atmospheric CO2 • Greenhouse gases • N deposition • Sediment transport • P loading • Climate change • Temperature • Rainfall • Sea level rise • winds • Means and extremes • Land cover change • Cropland expansion • Degradation • Deforestation • Biodiversity change • Extinctions • Domesticates • Invasives • Marine resources • Overfishing • Pollution • Habitat damage • Human development • Poverty alleviation • Per capita consumption level • Education • Urbanisation • Coastal trend • megacities • Economic development • Globalisation of trade • Technology development • Fossil fuel based energy systems • Tranport systems • High-input agriculture • Medical technology Population growth

  4. 2. The world is a complex, coupled human-ecological system Bode’s Law When you suppress the high-frequency, small disturbances in a system, the amplitude of the low-frequency events increases Examples: River canalisation often leads to bigger floods (hurricane Katrina) Fire suppression leads to uncontrollable conflagrations (Victoria) Financial securitisation instruments led to a meltdown (bank crisis) Overconnectivity As connectivity in systems exceeds a critical threshold, it becomes much more likely that shocks will propagate through them Examples: Global pandemics: AIDS, SARS, H1N1 Global speculative bubbles and consequent deflation

  5. Can developing countries rise to an acceptable level of human development without overloading the global environment? WWF 2008 Africa : Ecological Footprint and Human Wellbeing WWF– Gland, Switzerland and Global Footprint Network (GFN), Oakland, California USA.ISBN 978-2-88085-290-0 Ecological footprint Human Development Index

  6. Adapting to a hotter, stormier future

  7. Africaprojections2080-2099, 21 models, A1B scenario Rainfall Temperature +20% -20% +2 ºC +4ºC Source:IPCC AR4 WG1 ch 11

  8. Food supply insouthernAfrica Fisher, G et al (2002) Climate Change and Agricultural Vulnerability IIASA

  9. Observations: Fires in forestry plantations in southern Africa

  10. Predicted wave run-up as a result of sea level rise and storm changes Present storm run-up line Pot. future storm run-up line due to SLR Pot. future storm run-up line due to SLR & wave increase Requirements for predicting coastlines include: Improved understanding of interconnected coastal/physical processes (e.g. the interaction between sea-level rise and changing storm intensities); An accurate profile response model. Drawing a contour line is insufficient: E.g. more realistic run-up prediction techniques are required as illustrated in the figure above.

  11. Adapt or mitigate? Total cost curve Already incurred Commit- ted Cost of Impact and Mitigation % of Global GDP 5 1 1 1 2 3 4 5 6 (Global equilibrium temperature – preindustrial temperature) ºC

  12. The effect of procrastination Already incurred Commit- ted Cost of Impact and Mitigation % of Global GDP Total cost curve 5 1 1 1 2 3 4 5 6 (Global equilibrium temperature – preindustrial temperature) ºC

  13. Mind the gap!Emissions from South Africa through 2050 Staying competitive in a low-carbon economy Graphic: SA Long Term Mitigation Scenarios (2007)

  14. Many mitigation options exist

  15. Two bridges are needed to close the gap 2 Growth without constraints 1 Emissions (billion tonnes CO2eq) Technical solutions Required by science 0 2050 2003 Year Technical bridge Ethical bridge

  16. Persuading the world to take unified action to keep global warming tolerable • 3 C mean global temperature rise is regarded as ‘dangerous climate change’ • We have already incurred 0.7  C and are committed to ~ 1  C more • Staying below 3  C will require global emissions to peak by ~ 2020, then decline to below half of 1990 levels by 2050 • If developed countries are to get room to increase their emissions initially, developed countries need to decrease theirs by 90% • Polar regions, small island states, Africa, the Amazon and coral reefs suffer serious damage by that stage • If we aim at 3  C, there is a high chance we will actually exceed it © CSIR 2009 www.csir.co.za

  17. bscholes@csir.co.za012 841 2689

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