Climate Change is a significant change in temperature, wind patterns and precipitation that may occur in cycles over decades, hundreds, thousands and millions of years; sometimes these changes may be random occurrences. These may result in extreme weather events like thunderstorms, cyclones, tornados etc. In the recent years we are witnessing the impact of climate change occurring much faster and in much shorter period.

In the last century scientists detected that the temperature of earth was rising abnormally. It was found that oceans were warming up and snow was melting leading to rise in level of oceans. It was also found that there was perceptible rise in the carbon dioxide in the atmosphere.

Greenhouse Gases (GHGs) resulting from mainly industrial development and urbanization, agriculture and changes in land-use patterns are the cause of global warming. Different gases have different Global Warming Potential (GWP) which means how much damage they cause to the environment. The Carbon Dioxide (CO2) has GWP of 1; Methane - GWP of 21 and Nitrous oxide - GWP of 310.

The effects have been felt in India as well. There was all India drought in 2002. There was all India Severe drought in 2009. The year 2010 was one of warmest year. In the year 2013 there were Extreme rainfall events in Uttarakhand. We have seen mountains becoming baron due to large scale cutting of trees. This is resulting in hills becoming weak. Tsunami and Amphan and now Nisarga at our western coast.

Climate and weather have always had a powerful impact on human health and well-being. Global climate change is a newer challenge to ongoing efforts to protect human health. In the past few years there has been increased Mosquitoes Breeding, Malaria, Dengue and Yellow Fever. Increase in temperature by 2-3º C would increase the number of people who, in climatic terms, are at risk of malaria by around 3-5 per cent, which means several hundred million people globally. According to World Health Report 2002, climate change was estimated to be responsible in 2000 for approximately 2.4 per cent of worldwide diarrhoea, and 6 per cent of malaria in some middle-income countries.

In this century we have witnessed the outbreak of SARS, H1N1 Flu, Swine Flu and now the COVID-19. Several hypotheses are attributed to such outbreaks. The changing climate as a result of human activity has caused several changes in the flora and fauna. Viruses are known to mutate and the climate change is hastening the process.

Changes in atmosphere coupled with vehicular and industrial emissions lead to smog and poisonous gases which cause difficulty for those with cardio vascular disease, respiratory disorders as asthma, emphysema, chronic Bronchitis and allergy problems.

Similarly Water Pollution Related Diseases are on the rise. There is Poor quality of drinking water because water resources are threatened by drought, leading to bacterial, viral, Protozoal and Parasitic diseases.

The climate change has several indirect effects on our health. As a result of rising sea levels and flooding of the coastal areas, there occurs increase in population density due to migration of people to safe areas. People have to live in make shift camps in poor, unhygienic living conditions which cause several infectious diseases. Children lose their school. There may be violence for want of food and other basic amenities. This may lead to Psycho Trauma and Post Traumatic Stress disorder.

Arms race is an important cause of release of gases responsible for global warming. This occurs right from manufacture to transport to deployment to use of arms. Extreme changes in the climate may occur in the event of a nuclear fallout. A study conducted by Dr Ira Helfand, MD and Alan Robock et al on the climatic consequences of regional nuclear war shows clearly that even a “limited” nuclear conflict, involving as few as 100 Hiroshima-sized bombs, would also have global implications with significant effects on weather patterns throughout the world. Debris injected into the atmosphere from the explosions and resulting fires would produce an average surface cooling of -1.25ºC that would last for several years. Because of fall in temperature there would occur crop failure. This would result in serious food shortage. This would put the lives of over 2 billion people at risk.

Human-induced depletion of stratospheric ozone is another issue affecting human health. Stratospheric ozone absorbs much of the incoming solar ultraviolet radiation (UVR), especially the biologically more damaging, shorter-wavelength, UVR. The solar ultraviolet radiation may cause diseases of skin like Malignant Melanoma, Non-Melanocytic Skin Cancer – Basal Cell Carcinoma, Squamous Cell Carcinoma, Sunburn, Chronic Sun Damage, Photodermatoses. They may affect our eyes in the form of Acute photokeratitis and photoconjunctivitis, Climatic droplet keratopathy, Pterygium, Cancer of the cornea and conjunctiva, cataract, Uveal melanoma, Acute solar retinopathy and Macular degeneration. There is also negative impact on immunity. There may occur suppression of cell mediated immunity, Increased susceptibility to infection, impairment of prophylactic immunization, activation of latent virus infection.

The climate change also leads to altered general well-being, disturbed sleep/wake cycles, Seasonal affective disorder and disturbance in mood. Number of heat stroke related diseases is on rise during summer. Similarly due to erratic winter there is detrimental effect on human health.

The health effects of climate change also depend on other relevant factors like age and gender, socio economic condition, geographic locations—already cold areas/already warm areas/temperate regions, population density, sanitation and healthcare, nutrition, preexisting diseases, public healthcare system, literacy and infrastructure. People who are socially, economically, culturally, politically, institutionally, or otherwise marginalized are especially vulnerable to climate change.

There is urgent need to take steps to prevent climate change to save health. These may include policy making and Strategies to reduce risks of climate change. There is need to develop better infrastructure to combat negative effect of climate change. Holistic approach is needed to health care in form of better nutrition, job opportunities, housing, shelter, clean water etc. Also important are change in life style, equity, seriousness to the problem, international agreements and peoples campaigns.

“We have the means to limit climate change,” said R. K. Pachauri – Former Chair of the IPCC. “The solutions are many and allow for continued economic and human development. All we need is the will to change, which we trust will be motivated by knowledge and an understanding of the science of climate change.” (IPA Service)