Since the US Dust Bowl years of the 1930s, a great deal of reliable knowledge on reactive and anticipatory approaches to drought hazards and disasters has been derived. However, in an increasingly interconnected and rapidly changing world, several areas of concern are emerging. We highlight the following five areas of concern and opportunity:
1. Uncertainties associated with a changing climate and its manifestation at regional and local levels
There is a strong need to approach climate model outputs far more critically than at present, especially for impact assessment to support adaptation at the local level. Multiyear droughts are, at present, not addressed by any forecast system, including the increasing role of evaporative demand. Many hotspots that show fragility in the face of climate change also exhibit soil moisture and soil quality reduction combined with reduced adaptive capacity. Scenario planning (based on past, present, and projected events) may provide better understanding of whether and how best to use probabilistic information with past data and cumulative risks across climate timescales. Central to all of the above is a sustained network of high- quality monitoring systems.
2. The complex pathways of drought impacts: water-energy-food nexus
The United Nations (FAO 2014) describes the water-energy-food nexus as follows:
"Water, energy, and food are inextricably linked. Water is an input for producing agricultural goods in the fields and along the entire agro-food supply chain." Agriculture is currently the largest user of water at the global level, accounting for 70 percent of total withdrawal. The food production and supply chain accounts for about 30 percent of total global energy consumption. Energy is required to produce and distribute water and food, to pump water from groundwater or surface water sources, to power irrigation systems, and to process, store, and transport agricultural goods. Global demand for energy is expected to increase by 400 percent by 2050. In areas where hydropower plays a significant role in national energy supply, such as Brazil and Zambia, blackouts and jumps in energy prices have occurred during extended periods of drought. Similarly, in 2014 as a result of low flows, the Glen Canyon Dam (Colorado River) had to purchase US$60 million of thermal power to offset market demands in the US Southwest, the fastest growing region in the country. Since the 1990s, average increases in the yields of maize, rice, and wheat at global levels have begun to level off at just about 1 percent per annum (FAO 2017). There are many synergies and tradeoffs between water, energy use, and food production. Increasing irrigation might promote food or biofuel production, but it can also reduce river flows and hydropower potential through increased overall water withdrawals and, thus, jeopardize food security. In most cases, each component has been studied and managed individually, without consideration of the trade-offs, cultural similarities (and differences), interactions, and complementarity for jointly ensuring water, energy, and food security.
3. The costs of drought impacts and the benefits of action and costs of inaction The major assumption behind proactive action around drought is that present or upfront actions and investments can produce significant future benefits. Support for such claims has been difficult to document. However, a US study found that each dollar spent in three federal natural hazard mitigation grant programs (the Hazard Mitigation Grant Program, Project Impact, and the Flood Mitigation Assistance Program) saves society an average of US$4 in future avoided losses (Godschalck et al. 2009). This conclusion is derived from the fact that between 1993 and 2003 the US Federal Government spent US$3.5 billion on mitigation while saving society US$14 billion in estimated losses (Mittler et al. 2009). No such study exists for drought. However, in this volume, Gerber and Mirzabaev (Chapter 5) have begun to make some headway in assessing benefits of action and the costs of inaction. In the area of drought and other hazards, much more work needs to be done to realize what has been called the "triple dividend of resilience" (Tanner et al. 2015). The dividends provide for three types of public and private benefits that make a business case for proactive disaster risk investments and also a narrative for reconciling short- and long-term objectives. These benefits include:
a. Avoiding losses when disasters strike
b. Stimulating economic activity thanks to reduced disaster risk
c. Development cobenefits, or uses, of a specific disaster risk management investment
4. The role of technology, efficiency ... and policy
Since 1980, water use in the United States has returned to 1970 levels of use. During this period, the US population increased by 33 percent (Rogers 1993). This transformation illustrates the cumulative effectiveness of behavioral and efficiency changes. However, the major drivers were national policies reducing average annual demand and freshwater withdrawals in the United States (Rogers 1993), demonstrating the value of enabling legislation and regulation in leading to conservation measures. These included the Clean Water Act (1972), National Environmental Policy Act (1970), Endangered Species Act (1973), and Safe Drinking Water Act (1974). According to Stakhiv et al. (2016), these acts fostered and secured a bottom-up enabling institutional framework that focused on regulating, monitoring, and enforcing a suite of water quality and environmental laws passed in the 1970s.
5. Links to human security: an area for future research
According to a recent US National Intelligence Report, climate change and its resulting effects are likely to pose wide-ranging national security challenges for the United States and other countries over the next 20 years (NIC 2016). The pathways to insecurity outlined in this report include several drought-sensitive issues, such as:
- • Adverse effects on food prices and availability
- • Increased risks to human health
- • Negative impacts on investments and economic competitiveness
While water scarcity and food insecurity have been shown to play roles in dislocation and unstable conditions, little is known about the relationships of these links to conflict (Erian et al. 2010). Hydroclimatic variability poses an important threat to human security through impacts on economies and livelihoods, independent of the conflict pathway (Kallis and Zografos 2014 ; Serageldin 2009). How drought and climate change may play into future fragility will be an area of increasing research and security interest.
Godschalck et al. (2009) noted that valuable lessons for mitigation planners and policymakers have emerged over the years, including the need to consider a portfolio of losses, integrating both qualitative and quantitative analyses, assessing benefits and value over a large number of projects, the need to explicitly acknowledge differing social values, and strengthening institutional mechanisms for collaboration, including impacts data collection in order to reduce vulnerability and enhance resilience. As Vayda and Walters (1999) caution, researchers should focus on human responses to environmental events without presupposing the impact of political processes on environmental events. Linking a deeper problem-oriented contextual analysis of an event (or events) within a broader political ecology of conditioning factors driving vulnerability is needed. As has been noted, critique by itself is not engagement (Walker 2007).