The Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) was commissioned by the Intergovernmental Panel on Climate Change (IPCC) in response to a recognised need to provide specific advice on climate change, extreme weather and climate events (‘climate extremes’). The SREX report was written over two and a half years, compiled by 220 expert authors, 19 review editors and taking account of almost 19,000 comments. It went through three rigorous drafting processes with expert and government review. The findings were approved by the world’s governments following a four-day meeting, where the Summary for Policy Makers was agreed. It thus provides the most complete scientific assessment available to date and describes the immediate and long-term action required to manage the risks we face. It comprises a policy summary released in November 2011 and the full report released in March 2012 (available online at http://ipcc-wg2.gov/srex).

This thematic brief summarises the key findings of the report relevant to water resources and water management. It draws exclusively on material from SREX. It includes an assessment of the science and the implications for society and sustainable development. It is intended to be useful for policy-makers, decision takers and planners, locally, nationally and regionally. In recognition that these readers will have many competing calls on both their time and budgets, this brief seeks to highlight key thematic findings and learning from SREX. It makes suggestions for immediate action to avoid further damage from climate extremes and to build a more resilient future with benefits that go beyond water management.

Although not an official publication of the IPCC, this summary has been written under the supervision of co-authors of the SREX report and it has been thoroughly reviewed by an expert panel. The summary includes material directly taken from the SREX report, where the underlying source is clearly referenced, but it also presents synthesis messages that are the views of the authors of this summary and not necessarily those of the IPCC. It is hoped that the result will illuminate the SREX report’s vital findings for decision makers working on health issues, and so better equip them to make sound decisions about managing disaster risk in this context .This brief is one of four thematic briefs of the SREX report – on water, health, agriculture and ecosystems – that can be read individually or as a suite. There are also three regional SREX summaries for Africa, Asia, and Latin America and the Caribbean, which provide further information as a rapid reference source.

SREX considered the effects of climate change on extreme events, disasters, disaster risk reduction (DRR) and disaster risk management (DRM). It examined how climate extremes, human factors and the environment interact to influence disaster impacts and risk management and adaptation options. The report considered the role of development in exposure and vulnerability, the implications for disaster risk and DRM, and the interactions between extreme events, extreme impacts, and development. It examined how human responses to extreme events and disasters could contribute to adaptation objectives, and how adaptation to climate change could become better integrated with DRM practice. The report represents a significant step forward for the integration and harmonisation of the climate change adaptation, disaster risk management, and climate science communities.

For water sector policy-makers and planners, or indeed anyone whose work contributes to the management of water, this brief should prompt discussion and understanding of several questions:

1) Why are extreme events a critical issue for water management?

2) How is the water sector affected by the risk and impact of extreme events?

3) What actions can be taken to manage these risks?

What does SREX mean for water resources and water management?

A changing climate leads to changes in the frequency, intensity, spatial extent and duration of weather and climate events, and can result in unprecedented extremes, both through slow onset disasters (e.g. consecutive years of drought) and extreme events (e.g. heavy flooding). Many such events will have a direct impact on water resources now and in the future, including through increased frequency of heavy precipitation in many regions, intensified droughts across some areas, upward trends in extreme coastal high water levels, and changes in flood patterns.

Populations exposed to water-related hazards are already significant and are likely to increase. Water-related extreme events such as flooding, droughts and coastal inundation will have a broad range of impacts on humans and on ecosystems. These include economic losses, and pressures on particularly exposed human settlements such as coastal cities and Small Island Developing States (SIDS).

There is a high level of scientific confidence that changes in the climate could seriously affect water management systems  – such as water storage and treatment plants, and supply systems. A surplus of water can affect system operation, but more typically there is a shortage of water relative to demand – a drought. Water supply shortages may be triggered by a shortage of river flows and groundwater, deterioration in water quality, or an increase in demand.

There are several approaches that planners and policy-makers can take, working with other stakeholders, to help manage the risks presented by climate extremes and disasters and their impact on water resources and water management. These include: assessing risks and maintaining information systems; developing strategies to support coping and adaptation; learning from experience in managing risk; and linking local, national and international approaches.

As extreme climate and water-related hazard events increase in coming decades, climate change adaptation and disaster risk management are likely to require not only incremental but transformational changes in processes and institutions. This will involve moving away from a focus on issues and events towards a more holistic approach – for example, integrating water management with urban planning and design, and into policies on land use.

To read the entire CDKN report  Managing Climate Extremes and Disasters for the water sector: Lessons from the IPCC SREX Report please download at right of this page.