COVID-19 is far less dreadful than the Great Famine of 1315 and the Black Death of 1347; the former ended the period of growth and prosperity and caused millions of deaths, and the latter killed almost half of Europe’s population. But these worst episodes of plague and starvation pale in comparison to the foreseeable impacts of climate change. Scientists claim that the adverse effects of climate change are so great that they cannot be equated even with the fallout of a nuclear war. God forbid, if the global temperature rises by 5°C, we are likely to come across the sixth mass extinction, at par with the catastrophic demise of the large dinosaurs 65 million years ago.
Global warming which is the backbone of climate change, if it persists with the current rate, as many as one in six species could be at the risk of extinction/extermination by the end of this century. The golden toad of Central America has already vanished. The orange-spotted filefish, the quiver tree, the polar bear, the Adélie Penguin, the Indus River Dolphins of Pakistan, the North Atlantic cod and coral worldwide are some of the endangered species.
These effects are being seen around the world, though the threat is much higher in certain sensitive regions (including Pakistan and India). Unlike past mass extinctions, caused by events like asteroid strikes, volcanic eruptions, and natural climate shifts, the current crisis is almost entirely caused by humans. Extinction risk does not just increase with temperature rise, but accelerates, curving upward as the Earth warms.
The World Meteorological Organization says that the global temperature has already increased by 1.1°C since the pre-industrial age (1850-1900). And according to the most widely known and discussed “Stern Review” on the Economics of Climate Change (a 700-page report released for the British government on October 30, 2006) by Professor Nicholas Stern, there is a 75% chance that global temperature would rise between two and three degrees Celsius. However, in 2013 Nicholas publicly stated that he had underestimated the risks and that he now believes the world is on track for a four-degree rise in temperature, and if that happens hundreds of millions, probably billions, of people would have to move. It is predicted (by the International Bar Association) that there could be as many as 200 million climate refugees by 2050.
According to the United Nations, each of the last four decades has been hotter than the last, and the current decade (2010-2019) has been the hottest in recorded history. As per the World Meteorological Organization: “Oceans are now at their highest recorded temperatures, a quarter more acidic than 150 years ago, threatening vital marine ecosystems upon which billions of people rely for food and jobs. The global mean sea level reached its highest on record, fueled by the 329 billion tonnes of ice lost from the Greenland ice sheet in 12 months”. More than 20 million people have been displaced in the last year (2019) alone because of extreme weather events such as heatwaves, wildfires, and droughts, etc. The following are some of the disastrous impacts of global warming, as observed by scientists:
- Ice sheets have started melting at an alarming rate (for instance, from 1978 to 2004, ice cover in the Arctic has declined by 7.8 percent each decade. If these trends continue, late-summer sea ice could disappear from the Arctic as early as 2030).
- The shrinking of snow-clad mountains threatens drinking water supplies for millions of people; the melting of inland glaciers will increase water supply to rivers and lakes in the short to medium term, but this will cease once these glaciers have melted whereas 50 percent of the world’s freshwater supply is provided by mountain meltwater and runoff.
- Sea-level rise can lead to saltwater intrusion into groundwater drinking supplies.
- Half of the world’s population could face severe food shortages by the end of this century as rising temperatures shorten the crop growing season, increase the risk of drought, and reduce dietary harvests such as rice and maize by 20 percent to 40 percent, according to a scientific study. By 2040, food prices will be four times higher than they were in 2000. They’re already twice as high as they were in 2000.
- There has been a tremendous increase in frequency and intensity of disasters such as floods, tropical cyclones, severe storms, earthquakes, and tsunamis (when glaciers melt, massive weight on the Earth’s crust is reduced, and the crust “bounces” back. This process has the potential to reactivate faults, increase seismic activity, and lift pressure from magma chambers that feed volcanoes).
- The underwater heat waves have started killing coral reefs which help support 25% of all marine species. For instance, the bleaching of the Great Barrier Reef in 2016 and 2017 killed around 50% of its corals. According to UNESCO, if the current trend of global warming continues, the coral reefs in all 29 reef-containing World Heritage sites would cease to exist by the end of this century.
- Climate change may still seem far off for some, but for the people of the island nations, it is already a disturbing reality caused by the increase in sea-level.
- Precipitation patterns have changed dramatically because of the shifts in air and ocean currents, caused by climate change (some areas have started getting less and some more than the required rain with an adverse effect on agriculture).
- The springs have started coming earlier which leaves soil drier in summer and leads to more recurrent and penetrating heatwaves.
- Atmospheric humidity has increased (more “water vapor” intensifies global warming since it is also a greenhouse gas).
- Deserts have expanded (for instance Sahara Desert has stretched by about 10% since 1920).
The impacts of global warming are not based on speculations and weak probabilities. In fact, the scientific community has been able to measure and quantify precisely what will happen if the temperature rises as a direct consequence of global warming.
For instance, in 2005 parts of the Amazon basin experienced the worst drought in one hundred years. In 2010, it underwent more severe drought (the affected region was approximately 3 million square kilometers of rainforest, compared with 1.9 million square kilometers in 2005). In a typical year, the Amazon absorbs 1.5 gigatons of carbon dioxide; instead, it released 5 gigatons and 8 gigatons in 2005 and 2010 respectively. Additional severe droughts occurred in 2010, 2015, and 2016.
According to the Woods Hole Research Centre (which has been declared a world’s top climate change think tank for 2013, 2014, 2015, and 2016 by the International Center for Climate Governance) results, the amazon rainforest in its present form could survive only three years of drought. The scientists of World Wide Fund for Nature declared that the combination of climate change and deforestation increases the drying effect of dead trees that fuel forest fires. And the Brazilian National Institute of Amazonia concluded that the forest is on the brink of being turned into savanna or desert.
The Amazon as we know is a repository of ecological services not only for local communities but for the rest of the world. It is also the largest tropical rainforest that we have left in terms of size and diversity. Protecting the Amazon Basin is critical to our planet’s climate; it encompasses seven million square kilometers of the area which is home to about 16000 tree species, 40000 plant species, 2.5 million insect species, 2200 fishes, 1294 birds, 427 mammals, 428 amphibians, and 378 reptiles.
A new study to investigate how the Amazon would respond to future temperature rises, found that a 2°C rise, widely considered the best-case scenario, would still see 20-40% of the Amazon die off within 100 years. A 3°C rise would see 75% of the forest destroyed over the following century, while a 4°C rise would kill 85% of the Amazon. This will have further catastrophic effects on the climate – creating a vicious cycle, a dangerous ‘feedback loop’ since the rainforest absorbs and stores 10 to 20 percent of annual carbon dioxide emissions and supplies 6 to 10 percent of the world’s total oxygen per year.
An increase of 4°C may also melt permafrost which is permanently frozen soil, comprising 24% of the land in the Northern Hemisphere. Permafrost stores massive amounts of carbon. If it melts, at least 500 billion tonnes of carbon will be released which will make things even worse.
Global warming is a gradual increase in the Earth’s temperature because of energy trapped by greenhouse gases present in Earth’s atmosphere, by virtue of the greenhouse effect. So let’s understand what the atmosphere is, what greenhouse gases are, and what the greenhouse effect is?
The atmosphere is a layer of gases surrounding the planet Earth that is retained by Earth’s gravity. The average composition of the atmosphere up to an altitude of 25 km is as under:
|Gas Name||Formula||% Volume|
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since a part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. Greenhouses gases are:
- Carbon dioxide (CO2)
- Methane (CH4)
- Nitrous Oxide (N2O)
- Water vapor (H2O)
- Ozone (O3)
- Chlorofluorocarbons or CFCs
Earth is a rare planet to have a moderate greenhouse effect which is essential to support the complex patterns of life. Or else the planets with very little greenhouse effect are too cold for the survival of life, for instance, Neptune’s mean surface temperature is -200.15°C. And the planets with abundant greenhouse gases are too hot to live on, as in the case of Venus where the average temperature is about 456.85°C. The ranking of greenhouses gases by their direct contribution to global warming is as under:
- Carbon Dioxide 82%
- Methane 10%
- Nitrous Oxide 5%
- Fluorinated Gases 3% (Hydrofluorocarbons, Perfluorocarbons, Sulfur Hexafluoride & Nitrogen Trifluoride)
The current episode of Global Warming is attributed to increasing emissions of greenhouse gases, CO2 in particular, into Earth’s atmosphere because of the human-induced interferences. As per the data for the past 2000 years, the increase in global annual mean concentrations of CO2, CH4, and N2O – three important long-lived greenhouse gases has increased substantially and dramatically since 1750. According to the United States Environmental Protection Agency (EPA), figures of increase in greenhouse gas concentrations since the industrial revolution (as of 2016) are as under:
- Carbon dioxide has increased by more than 40%
- Methane has increased by about 250%
- Nitrous Oxide has increased by approximately 20%
- Human-induced interferences are of three types:
According to an estimate provided by the Energy Information Administration, 86.4% of the global energy requirement by 2007 was met from fossil fuels (petroleum 36.0%, coal 27.4%, and natural gas 23.0%). Fossil fuels contain high percentages of carbon (other more commonly used derivatives of fossil fuels are kerosene and propane). The burning of fossil fuels is the major reason for increase in greenhouse gas emissions, carbon dioxide in particular.
Explosion of Populations
The world population has risen from 2 billion to an alarming 7 billion during the last 100 years or so. More people mean more requirements for energy and more utilization of carbon emitting fossil fuels to meet that requirement. More people also mean more breathing wherein oxygen is inhaled and carbon dioxide is released by human beings. To add insult to injury, deforestation and forest degradation have decreased the planet’s natural carbon sink as trees are the major agents that extract carbon dioxide from the atmosphere and release oxygen therein, through the process of photosynthesis. Ten most populous countries in the world are China, India, USA, Indonesia, Brazil, Pakistan, Nigeria, Bangladesh, Russia and Japan.
Deforestation and Forest Degradation
In broader terms “Deforestation” is the clearing of trees, transforming a forest into cleared land, and “forest degradation” is a reduction in the capacity of a forest to produce ecosystem services such as storage of carbon, the release of oxygen, and provision of wood products. According to the World Wildlife Fund (WWF), deforestation has caused an estimated loss of 13 million hectares of forests between 2000 and 2010. And as per the Intergovernmental Panel on Climate Change (IPCC), deforestation and forest degradation are the second leading causes of human-induced greenhouse emissions following fossil fuel combustion, accounting for over 15 to 17% of global carbon dioxide emissions. Following are the countries with the highest deforestation in the world:
|5.||Papua New Guinea||250200|
The detail of greenhouse gas emissions by source is as under:
|1.||Carbon Dioxide||Electricity – 38%|
Transportation – 31%
Industry – 14%
Residential and commercial – 10%
Others – 7%
|2.||Methane||Natural gas and petroleum systems – 30%|
Enteric fermentation – 23%
Landfills – 17%
Coal mining – 11%
Manure management – 9%
Wastewater management – 3%
Other – 7%
|3.||Nitrous Oxide||Agricultural soil management – 69%|
Industrial chemical production – 9%
Stationary combustion – 6%
Transportation – 5%
Manure management – 5%
Others – 6%
All individuals, teams, organizations and governments must facilitate the following actions by providing resources, imparting skills and creating enabling environment (for efficient use of skills and resources) to stop the human-induced interferences that lead to global warming:
- Switch over to environment-friendly renewable sources of energy which are water, sun, and wind, and promote micro-generation rather than mega-generation.
- Build a culture of protecting forests and planting more and more trees; it is the easiest but the most effective measure that can turn the tables.
- Have one or two children at the most; less population doesn’t only ensure less need for energy, less burning of fossil fuels, and less carbon dioxide emissions, it also guarantees a better upbringing for your kids.
- Plan and insulate your buildings; air and light must reach every nook and corner (try to have at least two windows on separate walls of each room for cross-ventilation and maximum usage of sunlight). Use thermal insulation which ensures comfort as well as energy efficiency.
- Use energy-efficient light bulbs (light-emitting diode and compact fluorescent light); They are a bit expensive but always remember that the electricity used over the lifetime of a single incandescent bulb costs 5 to 10 times the original purchase price of the bulb itself.
- Use energy-efficient appliances; try to find the ‘Energy Star’ logo on washers and dryers, refrigerators, dishwashers, and air conditioners, etc.
- Turn off appliances at the power points; they consume power even in a standby power mode.
- Use solar panels to generate electricity; the price of environment-friendly solar power, together with batteries for storage, has continued to fall so that in many countries it is cheaper than ordinary fossil fuel electricity from the grid.
- Use solar geysers; it avoids greenhouse gas emissions on one hand and saves money on the other.
- Use clotheslines not dryers to make your laundry completely eco-friendly; wash full loads of clothes in cold water using a non-toxic, biodegradable laundry detergent with a vinegar rinse, then hang your clothes out to dry in the sun.
- Use fuel-efficient cars; your first choice should be hybrid cars and second the most fuel-efficient non-hybrid cars.
- Walk or ride a bicycle; besides reducing global warming, it will help you save money, burn fat, and remain physically fit.
- Use public transport; it saves money and ensures less consumption of fossil fuels. Besides, it eases congested travel corridors; as a result, automobiles traveling in these same corridors achieve greater fuel efficiency.
- Do not buy frozen food; besides being unhealthy, the frozen food coming from outside the town involves packing, shipping, and shelf-life issues. Moreover, it travels hundreds of miles to reach your dining table which means that buying local food prevents the burning of liters of fossil fuels.
- Eat less meat; some reports even suggest that greenhouse gas emissions produced by the global livestock industry are more than the emissions jointly released by all cars, planes, trains, and ships.
- Use recycled paper; by recycling a ton of recovered paper, 3.6 million tonnes of CO2 emissions are eliminated.
- Spread the word; learn more and more about climate change and share it with as many people as you can.
- Don’t use plastic bags (use fabric bags):
- In the USA alone, 12 million barrels of fossil fuels are used to manufacture 30 million plastic bags each year.
- An estimated one hundred thousand marine animals die each year from suffocating on or ingesting bags.
- Plankton is a crucial source of food to many large aquatic organisms, such as fish and whales. In 2004, researchers found 6 pounds of plastic for every pound of plankton in the North Pacific Gyre, the number increased by 8 times within the next four years.
- Even when disposed of properly, plastic bags take about 450 years to decompose and pose a serious threat because of dioxin and other toxins