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

© CSIR 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…. Have you noticed that everything seems to be going wrong at once? What is going on???

1. A globally-connected world Climate change Temperature Rainfall Sea level rise winds Means and extremes Biogeochemical change Atmospheric CO 2 Greenhouse gases N deposition Sediment transport P loading Land cover change Cropland expansion Degradation Deforestation Biodiversity change Extinctions Domesticates Invasives Population growth Urbanisation Coastal trend megacities Human development Poverty alleviation Per capita consumption level Education Technology development Fossil fuel based energy systems Tranport systems High-input agriculture Medical technology Economic development Globalisation of trade Marine resources Overfishing Pollution Habitat damage Non-human factors Orbital forcing Solar activity Tectonics etc

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

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 Human Development Index Ecological footprint

Adapting to a hotter, stormier future

Africa projections , 21 models, A1B scenario +4ºC+2 ºC -20% +20% Temperature Rainfall Source:IPCC AR4 WG1 ch 11

Food supply in southern Africa Fisher, G et al (2002) Climate Change and Agricultural Vulnerability IIASA

Observations: Fires in forestry plantations in southern Africa

Predicted wave run-up as a result of sea level rise and storm changes 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. 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

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

The effect of procrastination (Global equilibrium temperature – preindustrial temperature) ºC Cost of Impact and Mitigation % of Global GDP Already incurred Commit- ted 11 5 Total cost curve

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

Many mitigation options exist

Year Emissions (billion tonnes CO 2eq ) Growth without constraints Required by science Technical solutions Two bridges are needed to close the gap Technical bridge Ethical bridge

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 Persuading the world to take unified action to keep global warming tolerable © CSIR