The temperature increase in the atmosphere is more specifically referred to as global warming. But the climate change is the term currently favored by scientists, as it explicitly includes not only Earth’s increasing global average temperature, but also the climate effects caused by this increase.
Any gas, which has the property of absorbing infrared radiation emitted from Earth’s surface and reradiating it back to Earth’s surface, is called greenhouse gas. Carbon dioxide, methane, and water vapor are the most important greenhouse gases. Other greenhouse gases include, but are not limited to, surface-level ozone, nitrous oxide, sulfur hexafluoride, hydro fluorocarbons, per fluorocarbons and chlorofluorocarbons.
Though a naturally occurring phenomenon, the greenhouse effect results in a warming of Earth’s surface and troposphere – the lowest layer of the atmosphere. Of the greenhouse gases, water vapor has the largest effect.
Some important causes of greenhouse effect include burning of fossil fuels such as coal, oil and natural gas, deforestation, increase in population, farming, and industrial wastes and landfills.
Greenhouse gases trap heat in the atmosphere. With higher than normal concentrations, they lead to unnatural warming. The main cause of the current global warming trend is human expansion of the greenhouse effect, a warming that results when the atmosphere traps heat radiating from Earth toward space.
Even a small global temperature increase could lead to troubling consequences like rising sea levels, population displacement, disruption to the food supply, flooding, and ill-effects on health. As a matter of fact, human health bears the greatest brunt of the consequences of the climate change.
Ill-effects of climate change on health –
Climate change can affect human health mainly in two ways: first, by changing the severity or frequency of health problems that are already affected by climate factors and second, by creating health problems in places where they have not previously occurred.
Effects of temperature increase –
Increasing concentrations of greenhouse gases lead to an increase of both average and extreme temperatures. This can compromise the body’s ability to regulate its temperature. Loss of internal temperature regulation can result in a cascade of illnesses, including heat cramps, heat exhaustion, heatstroke and hyperthermia in the presence of extreme heat, and hypothermia and frostbite in the presence of extreme cold. Temperature extremes can also worsen chronic conditions such as cardiovascular disease, respiratory disease, cerebro-vascular disease, and diabetes-related conditions.
People working outdoors, socially isolated, economically disadvantaged and those with chronic illnesses are more vulnerable to the impact of temperature increase.
Effects of air quality –
Climate change has modified weather patterns, which in turn have influenced the levels and location of outdoor air pollutants such as ground-level ozone (O3) and fine particulate matter. Increasing carbon dioxide (CO2) levels also promote the growth of plants that release airborne allergens. Higher pollen concentrations and longer pollen seasons can increase allergic sensitization and asthma episodes, thereby limiting productivity at work and school. Poor air quality, whether outdoors or indoors, can negatively affect the human respiratory and cardiovascular systems.
Effects of extreme events –
Climate change causes an increase in the occurrence and severity of some extreme events, which can have health impacts such as death or injury during an event, for example, drowning during floods. Health impacts can also occur before and after an extreme event, as individuals involved in activities such as disaster preparation and post-event cleanup put their health at risk. The severity and extent of health effects associated with extreme events depend on the physical impacts of the extreme events themselves.
Vector borne diseases –
Vector-borne diseases are transmitted by vectors, which include mosquitoes, ticks, and fleas. These vectors can carry infective pathogens such as viruses, bacteria, and protozoa, which can be transferred from one host (carrier) to another. The seasonality, distribution, and prevalence of vector-borne diseases are influenced significantly by climate. Climate change is likely to have both short- and long-term effects on vector-borne disease transmission and infection patterns, affecting both seasonal risk and disease occurrence over decades.
Water related diseases –
Climate change is expected to affect fresh and marine water resources in ways that will increase people’s exposure to water-related contaminants which cause illness. Water-related illnesses include waterborne diseases caused by pathogens such as bacteria, viruses, and protozoa. Water-related illnesses are also caused by toxins produced by certain harmful algae and by chemicals introduced into water sources by human activities. Exposure occurs through ingestion, direct contact with contaminated drinking or recreational water and through consumption of contaminated fish and sea food.
Effects on mental health –
Mental health consequences of climate change range from minimal stress and distress symptoms to clinical disorders such as anxiety, depression, post-traumatic stress, and suicidal tendencies. The children, elderly, women (especially pregnant and post-partum women), people with preexisting mental illness, economically disadvantaged, and homeless are more exposed to its mental health consequences.
Effects on food safety and quality –
Climate change is very likely to affect global, regional, and local food safety by disrupting food availability, decreasing access to food and making utilization more difficult. Higher concentrations of CO2 can lower the levels of protein and essential minerals in a number of widely consumed crops, including wheat, rice, and potatoes, with potentially negative implications for human nutrition. Poor nutritional quality of food is more likely to affect adversely the vulnerable sections of the population.
The bottom line –
Over the last 50 years, human activities have released sufficient quantities of carbon dioxide and other greenhouse gases to trap additional heat in the lower atmosphere and affect the global climate. According to WHO (World Health Organization):
- Climate change affects the social and environmental determinants of health – clean air, safe drinking water, sufficient food and secure shelter.
- Between 2030 and 2050, climate change is expected to cause approximately 250000 additional deaths per year, from malnutrition, malaria, diarrhea and heat stress.
So, in view of the serious repercussions of climate change on human health, we all have to make concerted efforts to reduce emissions of greenhouse gases through better transport, food and energy use choices so as to improve our health particularly through reduced air pollution.