This chapter examines the potential impacts of climate change on the long-term performance and management of California's water system. Taking a comprehensive approach, it models the entire interconnected statewide water supply—including ground and surface waters, agricultural and urban demands, environmental flows, and hydropower—using CALVIN, an integrated economic-engineering optimization model. Unlike conventional simulation approaches, CALVIN economically optimizes system adaptation to changes in climate, population, land use, and agricultural technology, rather than being constrained by present-day operating rules and allocation policies. This approach has limitations but provides valuable insights for water policy and planning.

This chapter explores the impacts that rapid growth in biofuel demand has on agricultural prices, the consumption levels of key staple commodities, and the resulting impacts on food security and nutrition. The results clearly show a “food-versus-fuel” tradeoff that any national plan for biofuel expansion should take into account. Intensified biofuel production would likely increase the number of malnourished people. Rapid biofuel expansion also has a significant impact on international trade, particularly the global trade balance of maize. In addition, the results indicate that expansion of biofuels would increase the stress on regional water supplies only marginally; however, a significant expansion of biofuel production in areas facing water scarcity could exacerbate the problem. Aside from food security concerns, the expansion of biofuels entails additional tradeoffs with environmental sustainability, and the goals of overall economic growth and poverty reduction.

Two possible adaptation scenarios to climate change for Sub-Saharan Africa are analyzed under the SRES B2 scenario. The first scenario doubles the irrigated area in Sub-Saharan Africa by 2050, compared to the baseline, but keeps total crop area constant. The second scenario increases both rainfed and irrigated crop yields by 25% for all Sub-Saharan African countries. The two adaptation scenarios are analyzed with IMPACT, a partial equilibrium agricultural sector model combined with a water simulation module, and with GTAP-W, a general equilibrium model including water resources. The methodology combines the advantages of a partial equilibrium approach, which considers detailed water-agriculture linkages, with a general equilibrium approach, which takes into account linkages between agriculture and nonagricultural sectors and includes a full treatment of factor markets. The efficacy of the two scenarios as adaptation measures to cope with climate change is discussed. Due to the limited initial irrigated area in the region, an increase in agricultural productivity achieves better outcomes than an expansion of irrigated area. Even though Sub-Saharan Africa is not a key contributor to global food production (rainfed, irrigated or total), both scenarios help lower world food prices, stimulating national and international food markets.

In the long term, climate change will have a detrimental impact on the economies and people of Syria, Tunisia, and Yemen, but the most severe negative effects may take some time to materialize even without mitigation or adaptation measures. In Syria and Yemen, however, extreme climate variability has already weakened the agricultural sector, the economy, and people’s livelihoods. Syria suffers frequently from drought. Low rainfall leads to lower crop yields or, in extreme cases, to complete loss of the harvest, especially for rainfed agriculture. Droughts also harm the livestock sector, particularly animals that rely on pastures for feed. Prolonged periods of low rainfall exacerbate the impacts. Droughts are also likely to have an indirect effect on nonagricultural sectors of the economy and nonfarm households. Yemen, onthe other hand, is prone to damaging floods. Whereas regular flooding has traditionally been beneficial for agriculture in Yemen, high-magnitude flooding often leads to losses of cropland, uprooting of fruit trees, death of animals caught in high floodwater surges, and destruction of infrastructure, such as irrigation facilities and rural roads. Flood damage is exacerbated by ongoing desertification and land degradation. In addition, several GCMs predict higher
rainfall for Yemen, potentially increasing the frequency and severity of floods
in the future.

The Syrian Arab Republic, Tunisia, and the Republic of Yemen have taken
significant strides toward economic reform to accelerate growth, specifically in
the fields of trade, taxes, subsidies, foreign direct investment, and the develop-
ment of nonoil industries. But climate change may threaten any progress in development and pose a significant burden on economic growth and household incomes, especially for the poor, if the projected impacts are not incorporated into national planning. Climate change and extreme climate events such as droughts and floods will affect the economies of these three countries most through changes to global commodity prices and local agricultural production.

This report links results from crop models with global and national-level economic models to quantify the impacts of climate change and climate variability in the Syrian Arab Republic, the Republic of Yemen, and Tunisia. This modeling suite allows for a comprehensive assessment of global and local impacts of climate change and variability on important economic indicators, such as changes in agricultural growth and household income distribution.

The chapter reviews the status of and potential for water markets as an adaptive response to climate change, with implications for developing countries. An analysis of several climate change scenarios suggests increasing pressure on water supplies relative to demand, and points to regions of the world where water markets could help efficiently move water among users. Growing water scarcity and variability due to climate change might well propel development of new water markets given the significant potential of water markets to alleviate growing water stress both in the long run and in response to short term water variability.

We define water security as current and future access to sufficient water resources for productive uses and economic growth. At withdrawal levels in excess of 40% of available water resources, countries or river basins are considered water scarce, and thus water insecure. We find that in 2010, 36% of the world’s population, 39% of global grain production, and 22% of global GDP are at risk due to water stress. Moreover, under Business-as-usual (BAU), that is, if current policy and investments continue, more than half, or 52% of the global population, 49% of total cereal production, and 45% of GDP will be at risk due to water stress by 2050 with withdrawal levels above 40% of renewable resources. Water and food security are closely interlinked: increased water security also improves global food security and vice versa. As irrigation is, and will remain, the largest single user of freshwater withdrawals, large gains in water security can be made from small water savings in irrigated agriculture. However, productivity improvement in domestic and industrial sectors can also make important contributions in reducing the share of population and GDP at risk of water scarcity and should continue to be pursued.

This paper presents a robot manipulator for hand-over-hand guidance training of laparoscopic surgery. Details of the mechanical design, kinematic analysis and control mechanism of the robot are presented. The robot records motion of surgical tool manipulated by master surgeon, and provides physical guidance to the trainee based on the recorded motion. The robotic manipulator can accurately reproduce the five degree of freedom manipulation of laparoscopic instrument during surgery. A hybrid spherical mechanism is applied for decoupling and reproducing the motion of surgical tool to facilitate implementation of control mechanism. The manipulators for left and right hands are capable of precise execution of a recorded trajectory with observed maximum error of 2.12 mm and 2 mm respectively during an experiment on user interaction.