The roughly 2.8 billion of the world’s people who live on less than $2 per day are disproportionately affected by bad environmental conditions. They suffer most from the health effects of environmental factors such as dirty water, polluted air, poor sanitation and hazardous waste. Every year, between 5 and 6 million people die in developing countries from water-borne diseases and air pollution.

‘During the dry season, from August to January when the springs become dry, we have to walk 2 kilometres to Kishimbo to get water. When we reach there, we find that there are so many people lined up for water, it takes six hours to get one bucket.’ Oldadai, Arusha, United Republic of Tanzania

Premature death and illness caused by environmental health risks account for one-fifth of all disease in the developing world, more than the 15 per cent due to malnutrition, and greater than all other preventable risk factors and groups of disease. Diseases associated with environmental factors are highly concentrated among the poor. Around 60 per cent of all malaria deaths, and half of all fatalities from diarrhoea, for example, occur among the poorest 20 per cent of the world’s people. Can anything be done to reduce these risks? In sub-Saharan Africa, improved water and sanitation, cleaner household energy, better housing, vector control, and pollution management can reduce the total burden of disease by an estimated 23 to 29 per cent. And interventions in health care aimed at the diseases linked to environmental factors – such as diarrhoea, respiratory symptoms, eye diseases, and malaria – can cut it by a further 23 to 28 per cent.

Poor people, particularly those living in rural areas, also depend on natural resources such as water, soil and fisheries for subsistence and income. Yet environmental factors are seriously undermining the ability of the poor to wrest a living from natural resources.

Soil degradation, for example, now affects an estimated 65 per cent of cropland area in Africa, 51 per cent in Latin America, and 38 per cent in Asia. The livelihoods of more than a billion rural people are at risk as a result of desertification and dryland degradation. Water scarcity is a serious problem in many parts of the world; many countries are already consuming more than 100 per cent of their renewable water resources. Similarly, nearly 3 billion people depend on wood for household heating and cooking, yet many countries face a widening gap between their needs for fuelwood and sustainable supplies of it.

‘Sometimes... the water is brown. We call it tea, but we drink it anyway.’ Southwest Province, Cameroon

The links between poverty and the management of natural resources are complex and vary among regions and locations. Common concerns include property rights, incentives and institutions, and empowerment.

Communities often lack control over natural resources; the central government may own the forest, for instance, or prohibit harvesting of wildlife. Under these circumstances, the local community has no incentive to manage natural resources sustainably. Empowering them by granting them secure rights to use natural resources can dramatically improve incentives for sustainable management. Programmes such as CAMPFIRE in Zimbabwe – where communities were granted rights to harvest and manage wildlife for tourism – have been notably successful both in reducing poverty and in conserving the environment.

‘The consumption level of a poor household drops by fifty per cent in the wake of droughts... The women are expected to take their meals only after others in the household have finished eating. More often than not... women are left with practically nothing to eat.’ Bolangir, India

The poor are particularly vulnerable to shocks from environmental change and natural catastrophes – such as floods, storms, droughts and landslides – and they are also disproportionately affected by them. They tend to live in precarious housing, often located in environmentally vulnerable areas such as flood plains or steep slopes, putting them at greater risk from natural disasters and severe weather.

They also have less capacity to cope with disasters when they occur. It is much harder for them get to credit than better-off households, and they have fewer assets to sell or consume in times of hardship. So the disasters often have catastrophic effects on the poor.

The costs of natural disasters are immense. The 1997-1998 El Niño and Southern Oscillation event was directly responsible for 22 disasters that required international assistance; total costs were estimated at $25 to $36 billion.