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Human Impacts of Climate Change

An unbearable additional burden for the world's poorest.

Higher temperatures due to ever-greater concentrations of greenhouse gases in the earth’s atmosphere are having wide-ranging impacts on all regions of the world. But climate change is having a disproportionate adverse impact on the world’s poorest and most vulnerable populations. Many of the world’s poor already live in harsh environments, such as coastal flood areas, desert borderlands, tropical cyclone zones or urban shanty towns. Many already struggle to ensure their own survival or that of their family's, and live in communities lacking even the most basic services, such as medical care, running clean water, sanitation facilities or electricity.

In an already fragile situation, increasingly violent, frequent and unpredictable weather are a serious danger. Severe storms and floods have a phenomenal capacity for causing death and destruction, and today claim significantly more lives than conflict and war. While the more diffuse effects of our changing climatic conditions are placing vulnerable populations under multiple stresses.

Food Security
In general, dry areas are becoming drier, cutting access to water – the basis of life – particularly across Africa, the Middle East and Central Asia, the so-called “Drylands Belt”. In a number of coastal areas, higher water temperatures are having a negative impact on marine organisms, contributing to the depletion of fish stocks. Too much or too little rain, unpredictable weather patterns, insect infestations, severe storms, drought, and falling biodiversity are all cutting agricultural productivity and supplies of basic food staples. Vulnerabilities are increased through lack of access to accurate weather predictions, adequate irrigation infrastructure, adapted and modified seeds, and pesticides or fertilizers.

Heat, malnutrition and hunger facilitate the spread of vector borne diseases like malaria, schistosomiasis and dengue fever. Flooding can dramatically increase the likelihood of contracting water borne diseases, such as cryptosporidiosis, amoebiasis or typhoid fever, as clean water is often unobtainable or becomes contaminated. While little or no access to medical services and medication mean diseases go untreated and epidemics unrestrained.

Economic Impacts
Destroyed homes and infrastructure, successive failed harvests and perished livestock, or widespread infectious disease can have severe economic and productivity fall-offs for developing and least developed economies. Such communities often have no insurance protection whatsoever, which stalls recovery and prolongs economic hardship.

Social Impacts
Following major disasters or failed harvest seasons crime and tensions are likely to be exacerbated, children are more prone to be sent to work rather than to school, and in some regions, women more likely to enter into prostitution. Many of the worst affected zones are becoming entirely uninhabitable, causing whole communities to uproot and migrate to more hospitable areas. In addition, as climatic conditions deteriorate traditional knowledge linked to weather and rainfall patterns – dependable for generations – is now becoming unreliable.

Security Concerns
Tensions among vulnerable groups arise with the diminishing availability of basic resources, such as food and water, or when once arable land is rendered unproductive by encroaching deserts, seas or flood plains. In already difficult political contexts, such tensions can jeopardise national and regional security.

The Risks of Climate Change for the Poor

UNDP Human Development Report

Read the latest Human Development Report of the United Nations Development Programme (UNDP) "Fighting Climate Change: Human Solidarity in a Divided World".


The Scientific Assessment of Climate Change and its Impacts


Read the latest report of the Intergovernmental Panel on Climate Change.