Climate change refers to the long-term shifts in global temperatures and weather patterns. These changes could have natural causes such as variations in the solar cycle. However, since the early 1800s, the main driver of climate change has been anthropogenic (man-made) causes, including burning of fossil fuels such as coal, oil and natural gas.
The burning of fossil fuels emits greenhouse gases such as carbon dioxide and methane. These gases act like a blanket covering our earth, trapping the sun’s heat, and raising global temperatures.
The resulting global warming leads ultimately to global climatic change with adverse implications for agriculture, health, and environment, etc.
Some major causes of global warming:
Industrialization: It generates a lot of wastes that ends up in our atmosphere, in landfills, or surrounding environment; this pollutes the atmosphere, the soil and water bodies.
Farming: It converts natural ecosystems such as forests into farmlands; the farm animals also produce a lot of greenhouse gases e.g., methane as well as lot of farm wastes; industrial farming generates even more pollution and wastes.
Transportation: The alarming increase in the number of cars, planes. Boats and trains release massive amounts of greenhouse gases into the atmosphere further aggravating global climatic change.
Deforestation: As trees and forests are natural carbon sinks, as we clear more and more forests for the wood or create farmlands, the carbon sequestered in forests gets released into the environment, worsening the climate crisis.
Oil and Gas: They are used in almost every industry; in vehicles, buildings, and to generate electricity; consumption of coal, oil and gas adds to the climate problem.
Power Plants: They burn fossil fuels and generate a great variety of pollutants; this leads to air and water pollution as well as contributes to global warming; burning of coal (power plants) accounts for nearly 46 per cent of total carbon emissions.
Wastes: Humans generate much more waste now than before; they end up in landfills; when the wastes decompose, it releases harmful gases into the atmosphere which worsens the global warming.
Climate change and health
The WHO has christened climate change as “the single biggest threat facing humanity.” As out fragile planet continues to warm, billions of people across the world will experience worsening physical and mental health impacts. Some of the ways in which climate change may affect our health include:
Air pollution: It kills around 13 people every minute globally due to lung cancer, stroke and heart disease.
Plastic wastes: They are ubiquitous now-from ocean depths to mountain peaks; tiny plastic particles (microplastics) have now contaminated our food chains and even entered our bloodstreams with serious health effects which are yet to be fully understood.
Extreme weather events: These events e.g. drought will have severe impact on agriculture and food production leading to food insecurity and malnutrition.
Scarcity of safe drinking water: Climate change is causing dearth of safe and clean drinking water; 2 billion people currently lack access to safe drinking water; and about 8,29,000 people die from diarrheal disease every year due to consumption of contaminated water and poor sanitation.
Deforestation: Around 600 million trees are cut down every year; the loss of biodiversity is known to increase disease spread between animals and humans (zoonotic diseases).
Vector-borne diseases: As temperatures rise, mosquitoes (and other vectors) spread further in northern latitudes; malaria and other diseases will appear in places where they were never seen earlier; an additional 4.7 billion people could face the risk of malaria and dengue fever by 2070.
Mental Health: Climate change will also impact our mental health; due to extreme weather events, stress and anxiety will increase especially among children, adolescents and elderly.
Emerging diseases
Climate change may trigger the emergence of many new diseases. We don’t have the time and space to discuss all of them here. Nonetheless, some of the serious emerging diseases humanity may face include:
Melioidosis: Causes by a bacterium, Burkholderia pseudomallei, especially in tropical and subtropical countries.
Candida auris: An emerging nasty yeast pathogen.
Lyme disease: Caused by Borrelia bacteria and transmitted by ticks.
Ebola: A dangerous viral disease.
Nipah virus: Another serious viral disease.
Dengue: Another viral disease spread by Aedes mosquitoes.
Measles: Viral disease
Avian Influenza: Another viral disease.
Climate change and agriculture
Climate change will seriously impact global food security. Agriculture is extremely vulnerable to climate change. Some ways in which global climate change would hit agroecosystems include rising temperatures, untimely droughts and floods, shifting agroecosystem boundaries, rise of invasive crops and pests, and more extreme weather events such as cyclones, storms and hurricanes etc.
Climate change would reduce crops yields, lower the nutritional quality of major cereals, and decrease livestock productivity. There is urgent need to develop “climate smart agriculture.” New methods of farming with less water and agrochemicals are needed to produce “more crops per drop.” Also, it’s urgently warranted to drastically cut down the use of synthetic fertilizers and pesticides and use more of microbial bioinoculants, biocontrol agents and fertilizers.
Climate change and other environmental sectors
Due to accumulation of greenhouse gases and rising temperatures, there would be sea level rise threatening life security in low-lying areas e.g., Bangladesh. Ocean water will is becoming more acidic, leading to coral bleaching; coral reefs are dying in several areas of the global seas. Microplastics are also causing deaths of severe marine life-forms.
On the one hand, climate change will enhance the frequency of wildfires in forests. As population rises and development expands, more forests would be eroded. And, more forests may be converted into farmlands. In contrast, in some regions, as temperatures rise, forests may expand and move northwards, but will this cause more cooling effect is not yet clear.
There also may be drastic impacts on global biogeochemical cycles but we cannot discuss that here.
Mitigation measures
The science of climate change and its mitigation is quite advanced now. We know that temperatures have been rising indeed. And, we need to urgently take steps to reduce greenhouse emissions. What is lacking is the political will among the global leaders.
Some mitigation steps that may ameliorate climate change include, inter alia, the following:
- Shift to LED light bulbs and energy-efficient electric appliances.
- Eat more plant foods and reduce consumption of meat (farming meat animals emit much more greenhouse gases that farming plants)
- Expand the use of electric cars and vehicles
Conserve forests, initiate afforestation and reforestation projects on a large scale
-Throw away less food
- Reduce, reuse, repair and recycle
- Expand the use of renewable energy such as solar and wind energy
- Insist on buying eco-friendly products
- Grow and consume more local foods
- Improve public transportation networks.
Unless we take urgent steps to drastically reduce greenhouse gas emissions, to conserve forests, wildlife and biodiversity, to expand renewable energy resources, enhance the use of public transport and electric run vehicles, cut down the generation of plastics and wastes and reduce the consumption of meat, humanity’s continued survival may be seriously at risk in the next few decades!
