Introduction: Climate Volatility and the Poor in

Southern and Eastern Africa

Will MartinDar es Salaam, Tanzania

24 February, 2010

Supported by the Trust Fund for Environmentally and Socially Sustainable Development

Why are we concerned?• The poor in Africa are perhaps the most

vulnerable to climate change

What are the goals of this project? • Understand the likely impacts on Tanzania

– Through climate change, crop responses, economic impacts, household responses

• Consider policy responses to promote resilience

Interdisciplinary Research is Challenging!

4

Welcome

So you need great collaborators!

Carbon Emissions

Impacts

Policy Responses

Adaptation Emissions ReductionFinancing

Natural Systems

Human Systems

Climate Science Debate

Detection: - Little doubt about global warming – despite recent cold weather in N. Hemisphere - Rise in atmospheric CO2 also unambiguous, as are man-made contributions

Attribution: -Much more complex- Making the connection from rising GHG concentrations to global warming/climate change requires a “counterfactual” experiment: what would the temperature be in absence add’l GHGs?- Hence need for climate models

Not dissimilar to the problem faced by economists who cannot conduct controlled experiments. E.g., what was the impact of the Uruguay Round on Tanzania?

To measure impact of increased GHG releases on climate, calibrate model to track current climate with observed GHG, then run counterfactual without human GHG emissions: What lessons can we learn?

Source: IPCC, 2007

IPCC 2007: Key Points Africa

• Among most vulnerable continents to climate change and climate variability– aggravated by the interaction of ‘multiple stresses’,

occurring at various levels, and low adaptive capacity.

• IPCC suggested that agricultural production and food security may be severely compromised– Crop yields likely to fall

World Bank Research• World Development Report 2010

– 2°C warming by 2050=> 4-5% reduction in annual income per capita in Africa & S. Asia, vs global avg. GDP drop of 1%

• Economics of Adaptation to Climate Change:– Estimated cost between 2010-50 of adapting to ~2°C warmer

world by 2050 = USD 75-100 billion a year– 7 country case studies, incl Ghana, Ethiopia, & Mozambique

• Development Prospects Group– Emission controls, border tax adjustments, agricultural

productivity, distributional impacts

• Numerous other projects

Source: WDR, 2010

Key Points Tanzania

• IPCC (2007) focuses on water sector vulnerability– Interannual lake-level fluctuations and lake-level

volatility owing to periods of intense droughts followed by extreme rainfall events especially in late 1997 (e.g., in Lakes Tanganyika, Victoria and Turkana).

– Mt. Kilimanjaro (see figure)

Source: IPCC, 2007

Knowledge Gaps: Climate Volatility & Poverty

• Lobell et al (2008) and Battisti and Naylor (2009)– Extreme climate events will reduce agricultural output in the

tropics & reduce food security in developing countries. – Food insecurity driven by declines in food production

• Primarily rain-fed agriculture makes Tanzania especially vulnerable– only 2 percent of arable land has irrigation facilities

• Majority of the poor live in rural areas where agriculture is the dominant economic activity– Poor consumers are very vulnerable to food price rises

• Few Tanzania-focused analyses of climate impacts on economy or poverty

How does this project contribute to filling knowledge gaps?

• Tanzania focus• Focus on climate volatility & extremes• Integrated analytical framework: climate

volatility-crop modeling-economic simulation• High resolution climate modeling for Africa• Statistical & simulation based crop response• Poverty impacts at global, national, &

subnational levels

Percentage Change in Intensity of 1 in 30 Year Extreme Dry Spell, 1971-2001 vs 2070-99

Source: Diffenbaugh, forthcoming

Precipitation: Averages & Trends

Source: Rowhani et al

Analytical Framework

18

CLIMATE ANALYSISSTATISTICAL ESTIMATIONOF CROP YIELDS

GLOBAL ECONOMIC SIMULATION MODEL

HOUSEHOLD MODEL

GRAIN YIELD PREDICTIONS

temperature & precipitation, from General Circulation Models Predicted changes in

crop output, current + future climate

changes in prices & wagesfrom simulation results

POVERTY IMPACTS

Parallel biophysical simulationmodeling

ECONOMIC IMPACTS

NATIONAL ECONOMIC SIMULATION MODEL

State of Play

• Fundamental analyses completed– Survey of the relevant literature– Projections of changes in climate & volatility– Estimated crop responses to climate change– Impacts on poverty world wide & in Tanzania– Regional impacts on poverty within Tanzania

• Your feedback and input sought– Especially on how best to contribute to policy

Today’s Presentations

1. Tom Hertel: Review of the science and economics of climate change, agriculture and poverty

2. Syud Amer Ahmed: Global analyses of climate volatility & poverty, adaptation potential of trade

3. Channing Arndt: Impacts of climate change at the regional level in Tanzania