In recent years, several extreme weather disasters have partially or completely damaged regional crop production. While detailed regional accounts of the effects of extreme weather disasters exist, the global scale effects of droughts, floods and extreme temperature on crop production are yet to be quantified. Here we estimate for the first time, to our knowledge, national cereal production losses across the globe resulting from reported extreme weather disasters during 1964-2007. We show that droughts and extreme heat significantly reduced national cereal production by 9-10%, whereas our analysis could not identify an effect from floods and extreme cold in the national data. Analysing the underlying processes, we find that production losses due to droughts were associated with a reduction in both harvested area and yields, whereas extreme heat mainly decreased cereal yields. Furthermore, the results highlight ~7% greater production damage from more recent droughts and 8-11% more damage in developed countries than in developing ones. Our findings may help to guide agricultural priorities in international disaster risk reduction and adaptation efforts.

No abstract

7Climate volatility will increase in the future, with agricultural productivity expected to become increasingly volatile as well. For Tanzania, where food production and prices are sensitive to the climate, rising climate volatility can have severe implications for poverty. We develop and use an integrated framework to estimate the poverty vulnerabilities of different socio-economic strata in Tanzania under current and future climate. We find that households across various strata are similarly vulnerable to being impoverished when considered in terms of their stratum's populations, with poverty vulnerability of all groups higher in the 21 st Century than in the late 20 th Century. When the contributions of the different strata to the national poverty changes are taken into account, the rural and urban households with diversified income sources are found to account for the largest poverty changes due to their large shares in initial total poverty.

No abstract

Climate models generally indicate that climate volatility may rise in the future, severely affecting agricultural productivity through greater frequency of yield-diminishing climate extremes, such as droughts. For Tanzania, where agricultural production is sensitive to climate, changes in climate volatility could have significant implications for poverty. This study assesses the vulnerability of Tanzania's population to poverty to changes in climate variability between the late 20 th Century and early this century. Future climate scenarios with the largest increases in climate volatility are projected to make Tanzanians increasingly vulnerable to poverty through its impacts on staple grains production, with as many as 90 thousand additional people, representing 0.26 percent of the population, entering poverty in the median case. Extreme poverty-increasing outcomes are also found to be greater in the future under certain climate scenarios. In the 20 th Century, the greatest predicted increase in poverty was equal to 880 thousand people, while in the 21 st Century, the highest possible poverty increase was equal to 1.17 million people (approximately 3.4 percent of the population). The results suggest that the potential impacts of changes in climate volatility and climate extremes can be significant for poverty in Sub-Saharan African countries like Tanzania.