05 November 2022 – The Hindu

Climate Change

Introduction:

• Climate change is the term used to describe the recurring alteration of the Earth’s climate caused by fluctuations in the atmosphere and by interactions between the atmosphere and other geologic, chemical, biological, and geographic elements of the Earth system.
• In its 2018 special assessment on the effects of 1.5°C, the IPCC stated that quick, extensive, and unheard-of adjustments are necessary for every aspect of civilization to keep global warming to 1.5°C.
• Depending on how successfully various societal and environmental systems can adapt to or mitigate the consequences of climate change, various places will suffer differing degrees of damage over time.
• Increases in the global mean temperature of less than 1.8 to 5.4 degrees Fahrenheit (1 to 3 degrees Celsius) are anticipated to be beneficial in some regions and calamitous in others.
• Net annual expenditures will climb in tandem with rising global temperatures over time.
• The term “climate change” is frequently used to refer to the increase in global temperatures that has taken place since the middle of the 20th century.

About the Intergovernmental Panel on Climate Change (IPCC):

• In its Fifth Assessment Report, which was released in 2013, the IPCC agreed that human activity is the primary driver of climate change and that it is a real phenomenon.
• The average global temperature increased by 0.85°C between 1880 and 2012.
• The Fifth Review Report examines the causes of the sea level rise over the past few decades in great detail.
• Additionally, it provides a CO2 budget for future emissions to keep warming under 2°C and projects total CO2 emissions dating back to pre-industrial times. About half of this total have been distributed as of 2011.
• Sea levels have risen, ocean temperatures have changed, and snow and ice cover have all changed.
• Given existing concentrations of greenhouse gases and ongoing emissions, it appears likely that by the end of this century, the average world temperature will have risen above pre-industrial levels.

Effects of climate change:

• Alarming research suggests that crucial tipping points that may have have been reached or crossed may have permanently altered the earth’s climate system and significant ecosystems.
• Extreme weather, altered wildlife populations and habitats, rising sea levels, and many other effects of climate change are just a few.
• Temperature rises: The average temperature climbed by around 0.7°C between 1901 and 2018.
• It is anticipated that by the end of the twenty-first century: o The temperature may rise by around 4.4°C in compared to the years 1976–2005. Over India, summer heat waves might happen three to four times more frequently.
• Future generations will be impacted by the rapid melting of mountain glaciers since there will be less water available during the drier months.
• Change in Rainfall Pattern: Between 1951 and 2015, India’s summer monsoon rainfall fell by 6%, with the Western Ghats and the heavily populated Indo-Gangetic plains experiencing the biggest drops.
• Localized occurrences of heavy rain and dryness are increasingly common today.
• Drought: Every ten years between 1951 and 2016, the area impacted by drought expanded by 1.3%.
• There have been more than two droughts on average during this time in central India, the southwest coast, the southern peninsula, and northeastern India.
• Floods: Since 1950, there have been increased instances of flooding, which is partially attributable to an increase in the frequency of localised, transient periods of unusually heavy rainfall.
• Ice melt: As ocean temperatures rise, ice melt will continue. In compared to the 1986–2005 reference period, forecasts show that the average sea level will rise by 24–30 cm by 2065 and by 40–63 cm by 2100. (IPCC)
• Sea ice in the Arctic has shrunk since 1979, losing an average of 1.07 106 km2 of ice per ten years. (IPCC Report)
• Sea level rise: Between 1880 and 2012, the average global temperature increased by 0.85°C.
• In contrast to the current rate of global mean sea level rise, it increased at a rate of 1.06-1.75 mm per year between 1874 and 2004 before speeding up to 3.3 mm per year between 1993 and 2017.
• Additionally, compared to the global average increase of 0.7°C between 1951 and 2015, the tropical Indian Ocean’s sea surface temperature (SST) increased by an average of 1°C.

As a result of climate change:

• Health: It is predicted that as a result of climate change, the air quality will get worse, more people will get sick from water-borne illnesses, more people will experience heat stress, and more insects and rodents will carry more diseases. Extreme weather conditions may exacerbate a few of these health hazards.
• Agriculture: According to an NITI Aayog report, 68% of the cotton, 73% of the oilseeds, and 80% of the country’s pulses are produced by rain-fed agriculture.
• Farmers experience increased stress as a result of ongoing agricultural failures, which leads many to consider suicide.
• Rising energy requirements for space cooling are predicted to follow rising temperatures, increased GHG emissions, and more global warming.
• Increased biomass and foliage of plants and other vegetation result from higher CO levels, which will also affect the ability of agricultural plants to produce food.
• The increase in ocean heat waves, also known as marine heat waves, is having an effect on the marine environment, which includes corals and phytoplankton.
• Impact on the economy: India may lose 34 million full-time employment by 2030 as a result of productivity losses brought on by heat stress, according to the International Labor Organization.
• Drought, land degradation, and desertification cost India 2.5% of its gross domestic product in the two years between 2014 and 2015, according to the Ministry of Environment, Forests, and Climate Change.
• The World Bank estimates that the cost of health care and lost productivity due to pollution may amount to 8.5% of GDP.
• According to the 2019 State of the Global Climate report, 22 million people would have relocated by December 2019 as a result of extreme weather events.
• In India, 2.7 million people were displaced in 2019 as a result of climate change. (highest point on Earth).

The greenhouse effect and GHGs:

• The greenhouse effect is the mechanism by which gases in Earth’s atmosphere absorb solar heat. Earth is significantly warmed up as a result of this mechanism. The greenhouse effect is one of the things that makes the Earth a pleasant place to live.
• As its name implies, the greenhouse effect works similarly to a greenhouse. A greenhouse is a building with glass walls and roof. Among the plants that are grown in greenhouses are tropical flowers and tomatoes.
• The interior of a greenhouse is always comfortable. The greenhouse is heated by the daylight, which also warms the plants within. The greenhouse is still fairly warm at night even if it is becoming colder outdoors. This is done in order to trap solar heat inside the greenhouse’s glass walls.
• The greenhouse effect functions essentially the same on Earth. Atmospheric gases like carbon dioxide operate as heat traps, similar to the glass roof of a greenhouse. These heat-trapping gases are referred to as “greenhouse gases.”
• During the day, the Sun radiates through the atmosphere. The Earth’s surface warms up with the sun. At night, when the Earth’s surface cools, heat is released back into the atmosphere. Some of the heat is successfully trapped by the greenhouse gases in the atmosphere. That is what maintains the cosiness and comfort of our surroundings.