TWO words that can be found at the centre of many discussions, debates and resolutions across the globe today are “climate change”. It refers to the changing weather pattern and associated changes on land surfaces, oceans and other related changes in the atmosphere. These changes have been occurring over a long period of time – more than 30 years.

Studies have shown that climate change can be due to the actions of human beings, as well as through natural processes, such as volcanic movements, radiation of the sun and other climatic conditions.

The Faculty of Earth and Environmental Sciences (FEES) of the University of Guyana (UG), in an exclusive discourse with the Pepperpot Magazine refers to climate change as a statistically significant difference in either the average state of the climate or in its unevenness, which has been continuing for an extended period.

“It is a phenomenon that impacts our ecological systems causing disruptions that impair the biological health of plants, animals, and humans. This relationship between human health, disease and climate is thought to predate written history,” representatives of the FEES stated.

Health, as defined by the World Health Organisation (WHO), is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. According to the FEES, climate change may impact all of these aspects, thus the need to examine some of the potential health impacts it can have on public health.

The WHO emphasises the fact that the complexity of the relationship between climate change and health is not yet fully understood. This is because of the far-reaching effects on the atmosphere, hydrosphere (all the water on the surface of the earth), lithosphere (crusty outer parts of the earth), and the biosphere (all the ecosystems of the earth), which are all major parts of the earth’s life support system. Therefore health effects will vary geographically with respect to the environment, topography and vulnerability of the resident population; the populations in developing countries are particularly vulnerable since they are constantly grappling with major public health concerns such as access to water and sanitation facilities and the required nutritional intake.

HEALTH IMPACTS
According to the FEES, warmer average temperatures will lead to hotter days and more frequent and longer heat waves, which have significant impacts on the health of human beings; noting that the WHO, this year, has indicated that in excess of 3.5 billion people are currently at risk due to a dramatic global increase in incidence, while the 2006 Stern Report estimated that a 4°C rise in temperature could increase the risk of dengue fever for approximately 2.5 billion people.

The primary ways in which heat waves impact health are due to dehydration and heat stroke. Heart failure and respiratory distress may all be induced by heat waves. Scientists have noted that heat waves have increased in frequency and intensity due to climate change. Weather conditions are also expected to adversely affect air pollution, which may further increase the risk of asthma attacks and other respiratory and cardiovascular health effects.

NATURAL DISASTERS
Increases in surface temperatures induce increases in the rate of evaporation and hence the intensity of rainfall which in turn increases the risk of flash-flooding. Climate change will, therefore, have dynamic effects on the hydrological cycle (evaporation of water from the ocean) to the extent that it will increase the frequency and severity of droughts and floods in many areas.

The WHO reported during this year that weather-related natural disasters have tripled since the 1960s and more than 60, 000 deaths have been attributed to these disasters annually, primarily in developing countries. These extreme weather events influence the availability and quality of water – an essential for life. Further, these changes will affect the incidence of diarrhoeal diseases, which includes water-related diseases such as cholera, typhoid, and dysentery, as well as amoebiasis, giardiasis and cryptosporidium. The organisation, therefore, estimates that 1.7 billion cases of childhood diarrhoeal disease and 525 000 deaths in children under five will occur globally every year; the majority of which are attributed to unsafe water supply, bad sanitation and hygiene practices.

PUBLIC HEALTH PROFESSIONALS
The floods of 2005 in Guyana were attributed to increased rainfall which resulted in an increased incidence of water-related diseases. Floods and droughts are generally associated with an increased risk of diarrhoeal diseases. This is due to the fact that heavy rainfall washes contaminants into water supplies, while drought conditions can reduce the availability of fresh water, leading to an increase in hygiene-related diseases.

Public health professionals noted that diarrhoeal diseases are extremely sensitive to climate, indicating that temperature and relative humidity have a direct influence on the rate of replication of bacterial and protozoan pathogens, and on the survival of enteroviruses in the environment. Diarrhoeal disease is one of the most important causes of disease burden deaths in developing countries.

“The incidence could be further increased since the coastline of Guyana is approximately two metres below sea level and this makes the country extremely vulnerable to flooding due to sea level rise,” FEES stated.

OTHER SIGNIFICANT FACTORS
Changes in temperature, precipitation, and extreme events will also facilitate an increase of mosquito or vector-borne diseases. The Anopheles, Aedes, and Culex mosquitoes are vectors of malaria, yellow fever, dengue fever, chikungunya and Zika; West Nile fever and Lymphatic Filariasis. And it has been projected that not only will these diseases increase in incidence but that they will emerge and remerge due to the lengthened geographical range as a consequence of the changing climate. “Guyana has certainly seen the emergence of Chikungunya and Zika in the last five years,” FEES indicated.

Studies have however stated that climate change alone will not be the only contributory factor to the increase in public health problems. In fact, they emphasise the importance of anthropogenic activities (such as bad land use practices, socioeconomic and cultural conditions, the use of pest control, access to healthcare, and human responses to disease risk) as other critical factors that will favour increased incidence of vector-borne diseases.

THE EFFECTS ON FOOD
The 2018 United Nations report on The State of Food Security and Nutrition in the World suggests that there are 821 million people now hungry and over 150 million children stunted… Malnourished individuals are extremely vulnerable to high levels of infection due to unsafe and inadequate water and sanitation facilities. Malnutrition is both a medical and social disorder and is responsible for 23 million child deaths annually. The WHO in 2003 deemed it the single most important risk factor to global health, accounting for an estimated 15 per cent of the global disease burden in disability-adjusted life years. It would appear that little has changed in the intervening years.

According to the FEES, the complex relationship between climate change and health cannot be overemphasised. There remain several areas of scientific and contextual uncertainty since climate change is one of several global environmental changes that affect health. This, however, does not underscore the need to act now.

“It is clear that the impacts are far-reaching and have implications for the physical, mental and social well-being of populations everywhere. In our quest to accomplish the Sustainable Development Goals (SDG), as well as to make our world more climate resilient, we must seek to improve our understanding of the impact of climate change on human health; the level of effectiveness of our education and awareness campaigns to aid prevention of disease; and our health surveillance capacity to the extent that it is able to forecast the size of developing epidemics, depending on the degree of climate change, in an effort to provide essential health care,” FEES advocated.