Almost 20 percent of the world's people depend on unimproved water supplies ot meet their daily needs. Urban populations are better served than rural, but even piped water from municipal supplies my be contaminated by disease-bearing organisms and industrial pollutants. To achieve the 2015 target, an additional 1.5 billion people will need to be served.

Human development depends on the environment's providing a variety of goods and services—now and in the future. But the links between environmental conditions and human welfare are complex. Environmental changes can make poverty worse by compromising health, livelihoods, and protection from natural disasters. And economic growth can create new stresses on the environment as the demand for environmental resources rises and the damaging by-products of economic activity accumulate. But environmental resources are needed to promote economic growth and reduce poverty, and growth itself creates the means and the demand for an improved environment.

Roughly 2.8 billion poor and near-poor people in the world—those living on less than $2 a day—are disproportionately affected by these bad environmental conditions. They are particularly vulnerable to shocks from environmental change and natural catastrophes. Every year around 5 million people in developing countries die from waterborne diseases and polluted air. The livelihoods of around 1 billion rural people are at risk because of desertification and land degradation. And up to two-thirds of the world's people are likely to be affected by water scarcity.