Executive Summary
When the rains withered and the forests turned into parched savannahs, the earliest humans drifted out of Africa in their quest for water. Farms, settlements, and eventually cities clustered along riverbanks and gave rise to great civilizations. Now, as then, economic activity remains tied to water availability. But this relationship will undergo unprecedented pressures, as the 21st century witnesses the collision of two powerful forces— burgeoning population growth, together with a changing climate. With population growth, water scarcity will proliferate to new areas across the globe. And with climate change, rainfall will become more fickle, with longer and deeper periods of droughts and deluges.
Erratic rains weigh heavily on communities and economies. Floods are so powerful a metaphor of the human experience that nearly every civilization—from classical antiquity, to the Abrahamic religions, to ancient Mesopotamia—tells of a deluge epic that changed the world. Although it is debated whether these myths have a basis in historical events, extreme weather events still reshape societies and permanently mark the lives of those who experience them. Over the past two decades, extreme rainfall events have affected about 300 million people on average every year. With climate change, such extreme episodes of rainfall are expected to increase in frequency. Adapting to changing trends in rainfall, although difficult in its own right, is a gradual and predictable process. Knowing how to address unpredictable rainfall shocks, of uncertain frequency and unknowable magnitude, presents an additional challenge brought by climate change.
Whereas floods are spectacular weather events that cause sensational damage, droughts are misery in slow motion with impacts that are deeper and longer lasting than previously believed. Although overflowing riverbanks and storm surges certainly pose major economic threats, this book demonstrates that the impacts of water scarcity and drought may be even greater, causing long-term harm in ways that are poorly understood and inadequately documented. Droughts can have health impacts, hamper firm productivity, accelerate the destruction of forests, and compromise agricultural systems.
This book presents new evidence to advance understanding on how rainfall shocks coupled with water scarcity impact farms, firms, and families.
On farms, the largest consumers of water in the world, impacts are channeled from declining yields to changing landscapes. In cities, water extremes, especially when combined with unreliable infrastructure, can stall firm production, sales, and revenue. At the center of this are families, who feel the effects of this uncertainty on their incomes, jobs, and longterm health and welfare.
Original source and full report: World Bank.
Posted on 24 October 2017
