Climate volatility could change in the future, with important implications for agricultural productivity. For Tanzania, where food production and prices are sensitive to climate, changes in climate volatility could have severe implications for poverty. This study uses climate model projections, statistical crop models, and general equilibrium economic simulations to determine how the vulnerability of Tanzania's population to impoverishment by climate variability could change between the late 20th Century and the early 21st Century. Under current climate volatility, there is potential for a range of possible poverty outcomes, although in the most extreme of circumstances, poverty could increase by as many as 650,000 people due to an extreme interannual decline in grain yield. However, scenarios of future climate from multiple climate models indicate no consensus on future changes in temperature or rainfall volatility, so that either an increase or decrease is plausible. Scenarios with the largest increases in climate volatility are projected to render Tanzanians increasingly vulnerable to poverty through impacts on staple grains production in agriculture, with as many as 90,000 additional people entering poverty on average. Under the scenario where precipitation volatility decreases, poverty vulnerability decreases, highlighting the possibility of climate changes that oppose the ensemble mean, leading to poverty impacts of opposite sign. The results suggest that evaluating potential changes in volatility and not just the mean climate state may be important for analyzing the poverty implications of climate change.

This Statement summarizes the results of the third in a series of consultations between agricultural scientists (in particular those interested in the conservation and use of crop diversity in plant improvement) and climate scientists on how to adapt agriculture to climate change. The first meeting, also held at Bellagio (3-7 September 2007), looked at the Conservation and Use of Global Crop Genetic Resources in the Face of Climate Change. It identified three major challenges facing the adaptation process: collecting crop diversity before it disappears, using it to breed better adapted crops, and informing key players of the increased need for the conservation and effective use of crop genetic resources in the face of climate change.

The second meeting, held at Stanford University on 16-18 June 2009, looked more specifically at breeding, and in particular at Climate Extremes and Crop Adaptation. Among other things, it recommended that efforts to develop heat tolerant cultivars of the major cereals be intensified, and that greater investments be made in genotyping and phenotyping the variation already held in genebanks, and in collecting remaining diversity.

This third meeting in the series, and second at Bellagio, focused on a specific area of intersection between the ground covered by the previous consultations: the role of plants that are closely related to crops but are not themselves cultivated (crop wild relatives, or CWRs for short) in breeding cultivars better adapted to future climates. We structured the discussion into three sections, and summarize the results in the same way below. We also note that the tight focus of this short meeting on CWR is not meant to indicate that other strategies for adaptation are less worthwhile. For example, changes in agronomic practices, such as the adoption of conservation agriculture, may well be an effective adaptation strategy, and one that complements crop genetic improvement. It was also often noted that the use of CWRs is but one of many tools in the breeder's toolbox.

Prevailing opinion assigns the Tibetan Plateau a crucial role in shaping Asian climate, primarily by heating of the atmosphere over Tibet during spring and summer. Accordingly, the growth of the plateau in geologic time should have written a signature on Asian paleoclimate. Recent work on Asian climate, however, challenges some of these views. The high Tibetan Plateau may affect the South Asian monsoon less by heating the overlying atmosphere than by simply acting as an obstacle to southward flow of cool, dry air. The East Asian "monsoon" seems to share little in common with most monsoons, and its dynamics may be affected most by Tibet's lying in the path of the subtropical jet stream. Although the growing plateau surely altered Asian climate during Cenozoic time, the emerging view of its role in present-day climate opens new challenges for interpreting observations of both paleoclimate and modern climate.

This paper aims to demonstrate the relationships between ENSO and rice production of Jiangxi province in order to identify the reason that ENSO might have little effect on Chinese rice production. Using a data set with measures of Jiangxi's climate and rice production, we find the reason that during 1985 and 2004 ENSO's well correlated with rainfall did not promote Chinese rice production. First, the largest effects of ENSO mostly occur in the months when there is no rice in the field. Second, there is almost no temperature effect. Finally, the monthly distribution of rainfall is almost the same in ENSO and neutral years because the largest effects are during months when there is the least rain. In addition, due to the high irrigation share and reliable and effective irrigation facilities of cultivated land, China's rice production is less climate-sensitive.