Climate change and health by Mubarak Mahmud

According to the United Nations (UN), effects of climate change on health are on the increase worldwide. The World Health Organization (WHO) reported that damages to health by climate change will cost between 2 billion USD to 4 billion USD per year by 2030. However, this is exclusive of damages to health determining sectors such as agriculture, water and sanitation. Climate change is expected to cause approximately 250,000 additional deaths per year due to malnutrition, malaria, diarrhea and heat stress between 2030 an 2050. Many infectious diseases including water borne ones are highly sensitive to climate conditions. According to the United Nations, Areas with weak health infrastructure mostly in developing countries will be the least able to cope without assistance to prepare and respond.

Climate change affects clean air, safe drinking water, sufficient food and secure shelter which according to the World Health Organization (WHO) are the major social and environmental determinant of health.


According to the WHO, household air pollution causes about 4.3 million deaths per year while ambient air pollution causes about 3 million deaths annually.

The Natural Resource Defense Council (NRDC) reported that Green House Gas (GHG) emission from power plants, vehicles and other sources can lead to smog pollution, ragweed pollen, increases in the ground level ozone and many other aeroallergens that can trigger and worsen respiratory allergies and asthma that affects about 300 million people.

Millions of people can be put to the risk of eyes, nose and lungs irritation when climate change lengthens the number of bad air days. This poses serious danger to asthma sufferers, elderly people, young children and people who work and exercise outdoors. Extreme heat contributes directly to death from cardiovascular, renal and respiratory diseases particularly among elderly people. According to Robin et. al., over 70,000 excess deaths was recorded in the 2003 European heat wave of summer.


Climate change affects the safety of drinking water through:

  1. Flooding: flooding can contaminate fresh water supply, increase the risk of water borne diseases such as cholera and creates breeding ground for disease carrying organisms such as mosquito that causes malaria (which kills over 400, 000 people every year mainly African children under five years of age) through formation of temporary pools. Flooding can also cause drowning and physical injuries, damages to homes and disruption in the supply of medical and health services.
  2. Variations in rainfall pattern: this affect fresh water supply that compromises hygiene and thus increases the risk of diarrheal diseases which kills over 500,000 children that are under five years of age every year. Moreover, extreme scarcity of water can lead to draught and famine which poses serious danger to food security. Climate change is also expected to lengthen the transmission season of important vector-borne disease and to alter their geographic ranges such as malaria, schistosomiasis and dengue. According to UN report, the conditions for dengue transmission are likely to expand significantly across the globe.


According to the WHO Malnutrition and under nutrition created by climate change causes over 3.7 million death per year generally through draught which directly negates availability of water for plant growth; floods and raising sea levels which destroys farms, stored agricultural products, inputs and facilities. This is of particular concern for a number of developing countries in Africa, Asia and Latin America.

According to the United States Medical Society Consortium, climate change is scientifically of great threat to nutrition. They reported that increases in the carbondioxide concentration actually resulted in a lower nutritional value of grown food such as wheat, rice, barley and potatoes. This occurs because plants produce less protein and more sugar/starches in a carbon-rich atmosphere. Plants are also less effective in taking essential minerals.


According to the WHO, globally, natural disaster has more than tripled since 1960 resulting to the death of over 60,000 people yearly mainly in developing countries with a displacement of over 22.5 million people.

Floods, hurricanes (such as Irma and Harvey which NASA confirmed links with climate change), fires, heavy rainfall and extremes of temperature caused by climate change poses a serious threat to secure shelter as it is subject to destruction when any of the above disaster occurs. This destroys homes, medical facilities and other essential services. 


Nigeria is the most populated, the most economic and the largest Green House Gases emitter in Africa, according to the Council of Renewable Energy (CRE) and it is the largest oil producer with the largest natural gas reserve in the continent. For this and many other reasons such as deforestation (of which Nigeria has the highest rate in the world according to Food and Agricultural Organization, FAO in 2005), Nigeria is currently under very heavy strike of climate change on health.

The Intergovernmental Panel on Climate Change (IPCC) reported that the mean air temperature in Nigeria between 1901 and 2005 was 26.6°C while the temperature increase for the 105 years was 1.1°C. This is obviously higher than the global mean temperature increase of 0.74 °C recorded since 1860 when actual scientific temperature measurement started. This made the World Health Organization to conclude and report that under a high emissions scenario, mean annual temperature is projected to rise by about 4.9°C on average from 1990 to 2100. If emissions decrease rapidly, the temperature rise is limited to about 1.4°C.

According to the World Health Organization (WHO) the impacts of climate change in Nigeria could include rising temperatures, more intense and frequent extreme weather events and sea level rise. For the population this could result in increased water and food insecurity, higher exposure to heat stress and ultraviolet radiation, changes in infectious and vectorborne disease transmission patterns and an increased threat to coastal communities facing sea level rise. However, they also reported that adequate adaptation and mitigation could help to protect public health, development, security and land and water resources from the potential threats posed by climate change.

The WHO and the United Nations Framework Convention on Climate Change (UNFCC) developed a 2015 Climate and health country profile for Nigeria and explained impacts as follows:


Under a high emissions scenario, and without large investments in adaptation, an annual average of 548,300 people is projected to be affected by flooding due to sea level rise between 2070 and 2100. If emissions decrease rapidly and there is a major scale up in protection (i.e. continued construction/raising of dikes) the annual affected population could be limited to about 300 people. Adaptation alone will not offer sufficient protection, as sea level rise is a long-term process, with high emissions scenarios bringing increasing impacts well beyond the end of the century.


Under a high emissions scenario, diarrhoeal deaths attributable to climate change in children under 15 years old are projected to be about 9.8% of the over 76,000 diarrhoeal deaths projected in 2030. Although diarrhoeal deaths are projected to decline to approximately 43,500 by 2050 the proportion of deaths attributable to climate change will rise to approximately 14.2%.


Nigeria also faces inland river flood risk. It is projected, that by 2030, an additional 801,700 people may be at risk of river floods annually as a result of climate change and 535,700 due to socio economic change above the estimated 621,100 annually affected population in 2010.


By 2070, under both high and low emissions scenarios over 400 million people are projected to be at risk of malaria. Population growth can also cause increases in the population at risk in areas where malaria presence is static in the future.



Without considerable efforts made to improve climate resilience, it has been estimated that the risk of hunger and malnutrition globally could increase by up to 20 percent by 2050. In Nigeria, the prevalence of child malnutrition in children under age 5 was 31% in 2013.


In Nigeria, 57% percent of an estimated 130, 900 child deaths due to acute lower respiratory infections is attributable to household air pollution (WHO, 2012).

Air pollution is now one of the largest global health risks, causing approximately seven million deaths every year. Air pollution in and around the home is largely a result of the burning of solid fuels (biomass or coal) for cooking. Women and children are at a greater risk for disease from household air pollution. Consequently, household air pollution is responsible for a larger proportion of the total number of deaths from ischaemic heart disease, stroke, lung cancer and the chronic obstructive pulmonary disease (COPD) in women compared to men.

There is an important opportunity to promote policies that both protect the climate at a global level, and also have large and immediate health benefits at a local level.


All populations are at risk of climate change but the following are more vulnerable according to the UN:

  • Small island developing states, coastal regions, mega cities, mountainous and Polar Regions.
  • Children living in poor countries
  • Elderly people
  • People with infirmities or pre-existing medical conditions such as HIV and asthma
  • Socially marginalized people (associated in some areas with indigenous population, poverty or migration status)
  • Areas with weak health infrastructure and
  • The impoverished and pregnant women


The World Health Organization (WHO) responses

In 2015, WHO executive board endorses a new working plan on climate change and health with the following major highlights:

  1. Partnership: to coordinate with partner agencies within the UN system and to ensure that health is represented strongly in the climate change agenda.
  2. Awareness rising: to present and disseminate information on the threat that climate change poses to human health and opportunities to promote health while cutting carbon emission.
  3. Science and evidence: to coordinate reviews on the links between climate change and health and develop global research agenda.
  4. Support for implementation of public health response to climate change: to assist countries to reduce health vulnerability to climate change while reducing carbon emission.

Nigerian government responses

The World Health Organization opined that Nigeria has:

  • In 1992 Nigeria signs the United Nations Framework Convention on Climate Change (UNFCC)
  • In 2004 Nigeria ratifies the Kyoto protocol
  • In 2009 Nigeria develops the vision 2020
  • In 2011 develops the national adaptation strategy and plan of action on climate change
  • Identified a national focal point for climate change in the Ministry of Health
  • A national health adaptation strategy approved by relevant government body
  • The National Communication submitted to UNFCCC which includes health implications of climate change mitigation policies
  • A current activity of implementing projects or programmes on health adaptation to climate change
  • Conducted a national assessment of climate change impacts, vulnerability and adaptation for health
  • Climate information included in Integrated Disease Surveillance and Response (IDSR) system, including Development of early warning and response systems for climate-sensitive health risks

Other worldwide adaptation responses

  • The integration of health into the National Adaptation Plans (NAPs) and programmes by some countries such as Macedonia and Germany.
  • The climate induced food insecurity analysis and practices developed by the world food programme to address programming and decision making in 16 countries across Asia, Middle East and eastern, central and northern Africa.
  • The Tiger Mosquito Monitoring Programme carrying out by Tiger Mosquito Surveillance Network in France.
  • The implementation of the Smart Hospital Toolkit and Smart Health Facilities in the Caribbean to support government in assessing and prioritizing vulnerability reduction programme in their facilities’
  • There are also a number of training and awareness-raising activities such as the self learning course on climate change and health developed by the Mexico’s National Institute of Public Health.


The health impacts of climate change have been well recognized in most parts of the world and numerous adaptation and mitigation strategies are taking place. Although Nigeria has an approved National Health Adaptation Strategy, and is currently implementing projects on health adaptation to climate change but more actions on mitigation and adaptation are needed.

The country shall:

  • Increase the awareness and understanding of the effects of climate change on health
  • Conduct valuation of co-benefits of health implications of climate mitigation policies
  • Implement activities to increase climate resilience of health infrastructure
  • Implement actions to build institutional and technical capacities to work on climate change and health
  • Assess the health effects of climate change
  • Expands knowledge, research results, and partnership.



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