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20.6. CLIMATE CHANGE AND HEALTH

Climate change poses a host of threats to the survival of mankind.


Each year, about 800,000 people die from causes attributable to air pollution, 1.8 million from diarrhoea resulting from lack of access to clean water supply, sanitation, and poor hygiene, 3.5 million from malnutrition and approximately 60,000 in natural disasters.

A warmer and more variable climate would result in higher levels of some air pollutants, increased transmission of diseases through unclean water and through contaminated food.

Climate change has a direct impact on human health.


For example, the warmer the climate the likelihood of its impact on human health becomes worse.


It is anticipated that there will be an increase in the number of deaths due to greater frequency and severity of heat waves and other extreme weather events.

Climate change and the resulting higher global temperatures are causing increasing frequency of floods and droughts leading to the risk of disease infections.

Lack of freshwater during droughts and contamination of freshwater supplies during floods compromise hygiene, thus increasing rates of diarrhoeal disease.

Endemic morbidity and mortality due to diarrhoeal disease primarily associated with floods and droughts are expected to rise in East, South and South-East Asia due to projected changes in hydrological cycle.

Flooding also creates opportunities for breeding of disease carrying insects such as mosquitoes.


Areas affected by frequent floods and drought conditions also witness large scale migration of populations to relatively stable regions leading to overcrowding and unhygienic conditions resulting in transmission of diseases like Japanese encephalitis and malaria.

Climate change is a major factor in the spread of infectious diseases. Diseases, confined to one specific geographic region spread to other areas.

The World Health Organization (WHO) in their studies have indicated that due to rising temperatures, malaria cases are now being reported for the first time from countries like Nepal and Bhutan.

It has also been predicted that an additional 220-400 million people could be exposed to malaria- a disease that claims around 1 million lives annually.

Dengue fever is already in evidence at higher levels of elevation in Latin America and parts of East Asia.


Studies suggest that climate change may swell the population at risk of malaria in Africa by 90 million by 2030, and the global population at risk of dengue by 2 billion by 2080s.

Rising temperatures and changing patterns of rainfall are projected to decrease crop yields in many developing countries, stressing food supplies. This will ultimately translate into wider prevalence of malnutrition/ undernutrition. In some African countries, yields from rain-fed agriculture could be reduced by up to 50 per cent by 2020.

Emission of the Green House Gases have been responsible for the depletion of ozone layer, which protects the Earth from the harmful direct rays of the sun. Depletion of stratospheric ozone results in higher exposure to the ultra violet rays of the sun, leading to an increase in the incidents of skin cancer. It could also lead to an increase in the number of people suffering from eye diseases such as cataract. It is also thought to cause suppression of the immune system.

The projections by WHO and IPCC suggest that the negative effects of climate change on health are greater.

In addition, the negative effects are concentrated on poor populations that already have compromised health prospects, thus widening the inequality gap between the most and the least privileged.

The balance of positive and negative health impacts will vary from one location to another, and will alter over time as temperatures continue to rise.

Do you know?


Saponins are a group of water-soluble glucosides that yield soap froth in water, form emulsions with oils and fats, and are capable of absorbing large amounts of gases such as carbon dioxide. Soap nut tree yields saponins.