Climate change encompasses both global warming and its effects on Earth's weather patterns. There have been previous periods of climate change, but the current changes are noticeably faster and are not the result of natural causes. They are instead caused by the release of greenhouse gases, primarily carbon dioxide (CO2) and methane. The majority of these emissions are caused by the use of fossil fuels for energy production. Additional sources include certain agricultural practices, industrial processes, and forest loss. Greenhouse gases are transparent to sunlight, allowing it to reach the Earth's surface and heat it. When the Earth emits infrared radiation, the gases absorb it, trapping the heat near the Earth's surface and contributing to global warming. In this article, we will discuss Climate Change which will be helpful for UPSC exam preparation.

Causes of Climate Change

Natural Causes

• Continental Drift: For millions of years, the movement of the tectonic plates has occurred. This causes a shift in weather patterns, which contributes to climate change over time.
• Plate Tectonics: Plate displacement is caused by the continuous change in temperature of the core of the Earth's surface. This has an impact on the local temperature of the environment as well as other codependent environmental elements, which causes climate change.
• Volcanic Activity: Although a volcano's eruption lasts only a few minutes, the consequences might last for years. A vast amount of carbon dioxide, dust particles, aerosol droplets, and other greenhouse gases enter the earth's atmosphere when lava erupts from a volcano.
• Ocean Currents: The horizontal movement of winds opposes the natural flow of ocean currents. As a result, it causes temperature variation, which leads to a change in the climate of the specific geographic region.
• Variation in Earth’s Orbit: The seasonal distribution of sunlight reaching the Earth's surface is affected by the Earth's orbit, causing an impact on geographical and seasonal variation. Thus contributing to climate change.

Anthropogenic Causes

• Greenhouse gases: Greenhouse gases are gases that absorb heat radiation from the sun and cause an increase in the temperature of the Earth's surface.
• Land-use Pattern: Large scale industrial use of land results in deforestation, and changes in agricultural patterns result in higher amounts of greenhouse gases.
• Atmospheric Aerosols: Aerosols are extremely small liquid particles that are trapped in the Earth's atmosphere. They scatter and absorb solar and infrared radiation, causing the temperature of atmospheric layers to fluctuate substantially.

*For detailed notes of this topic, check this link Causes of Climate Change

Global Warming

• Global warming is defined as an average increase in the temperature of the atmosphere near the Earth's surface and in the troposphere, which can influence global climate patterns.
• Global warming can be caused by a number of factors, both natural and man-made.
• In common parlance, "global warming" refers to the warming that can occur as a result of increased greenhouse gas emissions from human activities.
• According to the Intergovernmental Panel on Climate Change (IPCC) of the United Nations, a certain amount of global warming is inescapable and irreversible.
• This indicates that there is a likelihood of a 1.5 degree Celsius increase in global temperatures during the next 20 years.

*For detailed notes of this topic, check this link Global Warming

Greenhouse Effect

• The greenhouse effect is a naturally occurring phenomenon that blankets and warms the earth's lower atmosphere, keeping it at a temperature suitable for living things to survive.
• Water vapour and greenhouse gases warm the Earth in the same way that greenhouses keep the air warm inside their chambers.
• Greenhouse gases play an important role in the Earth's cooling and warming cycles.
• The greenhouse effect is a process (similar to the green house effect) caused by greenhouse gases that naturally occur in the atmosphere. This process is critical in warming the Earth's surface and making it habitable.
• Human-caused greenhouse gas emissions, on the other hand, disrupt the natural balance and lead to increased warmth.

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Greenhouse Gases

• Greenhouse gases are natural and anthropogenic gaseous constituents of the atmosphere that absorb and re-emit infrared radiation.
• Water vapour, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone are the primary greenhouse gases in the Earth's atmosphere.
• Such gases in the atmosphere act as a blanket, trapping/absorbing some of the infrared radiation emitted by the earth and releasing some of it to it.
• However, any rise in such gases would result in more heat trapping, resulting in an increase in earth's temperature, as represented in global warming.
• Without greenhouse gases, the average temperature of the Earth's surface would be around -18°C rather than the current average of 15°C.

*For detailed notes of this topic, check this link Greenhouse Gases

Climate Forcings

• Climate "forcings" are factors in the climate system that either increase or decrease the effects on the climate system.
• Positive forcings, such as excess greenhouse gases, warm the earth, whereas negative forcings, such as the effects of most aerosols and volcanic eruptions, actually cool the earth.
• Atmospheric aerosols include volcanic dust, soot from the combustion of fossil fuels, particles from burning forests, and mineral dust.
• Dark carbon-rich particles, such as diesel engine soot, absorb sunlight and warm the atmosphere.
• Exhaust from high-sulfur coal or oil, on the other hand, produces light aerosols that reflect sunlight back into space, producing a cooling effect. Aerosols formed naturally during volcanic eruptions cool the atmosphere.
• Large volcanic eruptions can eject enough ash into the atmosphere to lower temperatures for a year or more until the sulphate particles settle out of the atmosphere.

Types of Forcings

• Modifying the Energy Balance: The ability of a process to change the climate is measured by its "radiative forcing," or the change in the Earth's energy balance caused by the process.
• Some climate forcings are positive, resulting in global warming, while others are negative, resulting in cooling.
• Some, such as increased CO2 concentration, are well understood; others, such as aerosols, are less certain.
• Natural Forcings: Changes in the amount of energy emitted by the Sun, very slow variations in the Earth's orbit, and volcanic eruptions are examples of natural forcings.
• Since the beginning of the industrial revolution, the only long-term natural forcing has been a small increase in solar energy reaching Earth. However, this change is insufficient to account for the current warming.
• Forcings Induced by Humans: Human activities can also cause climate forcing. These activities include greenhouse gas and aerosol emissions from the combustion of fossil fuels, as well as land surface modifications such as deforestation.
• Greenhouse Gases Emitted by Humans: Greenhouse gases are a positive climate forcing, which means they warm the planet. Carbon dioxide emitted from fossil fuel combustion is currently the most powerful single climate forcing agent, accounting for more than half of total positive forcing since 1750.
• Aerosols Produced by Humans: The combustion of fossil fuels emits aerosols into the atmosphere. Aerosols are tiny particles in the atmosphere made up of a variety of substances such as water, ice, ash, mineral dust, or acidic droplets.
• Aerosols can deflect solar energy and influence cloud formation and lifetime.
• Aerosols are a negative forcing, which means they cool the environment.

Global Warming Potential

• The global warming potential (GWP) is the heat absorbed by any greenhouse gas in the atmosphere expressed as a multiple of the heat absorbed by the same mass of carbon dioxide (CO2).
• The global warming potential of each gas describes its impact on global warming.
• In terms of climate impact, the two most important characteristics of a GHG are:
  • how well the gas absorbs energy (preventing it from immediately escaping to space);
  • how long the gas remains in the atmosphere.
• The Global Warming Potential (GWP) of a gas is a measure of how much energy a gas absorbs over a specific time period (usually 100 years) when compared to carbon dioxide.
• Gases with a higher GWP absorb more energy per pound than gases with a lower GWP, contributing more to global warming.
• CO2 has a GWP of 1. Other gases are affected by the gas and the time frame.
• GWP is used to calculate carbon dioxide equivalent. The mass of CO2 would warm the earth as much as the mass of any other gas.
• As a result, it provides a common scale for assessing the climate effects of various gases. It is calculated as GWP times the mass of the other gas.

*For detailed notes of this topic, check this link Global Warming Potential

Receding Glaciers: A Symptom of Global Climate Change

• Glaciers, ice caps, and continental ice sheets cover about 10% of the earth's land surface today, but they covered roughly three times that amount during the ice ages.
• The current ice cover accounts for roughly three-quarters of the world's total freshwater resources.
• Deglaciation is the gradual melting of a glacier from the surface of a landmass.
• Ablation refers to the processes that remove snow, ice, and moraine from a glacier or ice sheet.
• Melting, evaporation, erosion, and calving are all examples of natural processes.
• The process of deglaciation, which accelerated in the twentieth century, is rendering our planet ice-free.
• There were 147 glaciers in Glacier National Park 150 years ago, but only 37 remain today, and scientists predict that they will melt by 2030.
• Similarly, glaciers in the Himalayas and Alps are receding and disappearing year after year. In the Polar Regions and high mountain environments, there are nearly 160,000 glaciers.
• As a result, researchers are increasingly employing satellite remote sensors to survey our planet's glaciers in a fraction of the time.

*For detailed notes of this topic, check this link Receding Glaciers: A Symptom of Global Climate Change

Impact of Climate Change

Higher Temperatures

• As greenhouse gas concentrations rise, so does global surface temperature. The last decade, 2011-2020, has been the warmest on record.
• Since the 1980s, each decade has been warmer than the previous one. Almost all land areas are experiencing more hot days and heat waves.

Severe Storms

• As temperatures rise, more moisture evaporates, exacerbating extreme rainfall and flooding and resulting in more destructive storms.
• The warming ocean also affects the frequency and size of tropical storms. Cyclones, hurricanes, and typhoons feed on warm water at the ocean's surface.

Increased Drought

• Global warming exacerbates water scarcity in already water-stressed areas, increasing the risk of agricultural droughts affecting crops and ecological droughts increasing ecosystem vulnerability.
• Droughts can also cause destructive sand and dust storms, which can transport billions of tonnes of sand across continents.

Oceans are Warming and Rising

• The ocean absorbs the majority of the heat emitted by global warming. Over the last two decades, the rate of ocean warming has increased dramatically at all depths.
• Because water expands as it warms, the volume of the ocean increases as it warms.
• Melting ice sheets raise sea levels, endangering coastal and island communities.

Changes in the Landscape

• Landscape change has contributed to the ongoing shift in land mass positioning, as well as the movement of flora and fauna towards the polar regions in search of a cooler environment to combat rising temperatures.

Rise in the Level of Sea

• Glacier melting is caused by global warming, which is caused by an increase in the temperature of the earth's atmosphere.
• All of this water combines with the ocean, causing a significant rise in sea level and increasing the risk of natural disasters such as floods in coastal areas.

Ocean Acidification

• Increased levels of carbon dioxide in the atmosphere cause increased absorption of carbon dioxide by the ocean, resulting in ocean acidification.
• As a result, aquatic species like planktons, mollusks, and corals lose their habitat.

Imbalance in the Ecosystem

• Changes in weather patterns disrupt the local environment, destroying suitable ecological conditions and the survival of indigenous species.
• This disrupts the ecosystem and devastates the natural environment.

Natural Disasters

• Draughts are occurring in various parts of the world as a result of a lack of adequate rainfall and a high intensity of solar radiation in that geographical area, depleting local species.
• Another effect of climate change is the rise in sea level, which causes flooding, hurricanes, and storms.

Species Extinction

• Climate change endangers the survival of species on land and in the sea. As the temperature rises, so do the risks.
• Climate change is exacerbating the loss of species, which is 1,000 times greater than at any other time in recorded human history.
• One million species are on the verge of extinction in the coming decades.

Not Enough Food

• Climate change and an increase in extreme weather events are among the causes of a global increase in hunger and malnutrition.
• Fisheries, crops, and livestock may be destroyed or depleted. Marine resources that feed billions of people are under threat as the ocean acidifies.

More Health Risks

• Climate change is causing health problems through air pollution, disease, extreme weather events, forced displacement, mental health strains, and increased hunger and poor nutrition in places where people cannot grow or find enough food.

Poverty and Displacement

• Climate change exacerbates the factors that cause and sustain poverty. Floods may wash away urban slums, destroying homes and livelihoods.
• Weather-related events displaced an estimated 23.1 million people per year on average over the last decade (2010-2019), making many more vulnerable to poverty.

*For detailed notes of this topic, check this link Impact of Climate Change

India's Response to Climate Change

National Action Plan on Climate Change (NAPCC)

• It outlines current and future policies and programmes addressing climate mitigation and adaptation.
• The Action Plan identifies eight core "national missions" that will run through 2017 - Solar Energy, Enhanced Energy Efficiency, Sustainable Habitat, Water, Sustaining the Himalayan Ecosystem, Green India, Sustainable Agriculture, and Strategic Knowledge for Climate Change.
• The majority of these missions have strong adaptation imperatives.

National Clean Energy Fund

• The Indian government established the National Clean Energy Fund (NCEF) in 2010 to finance and promote clean energy initiatives, as well as to fund clean energy research in the country.
• The fund's corpus is built by levying a cess of INR 50 (subsequently increased to INR 100 in 2014) per tonne of coal produced domestically or imported.

Paris Agreement

• India has made three commitments under the Paris Agreement.
• By 2030, India's GDP-related greenhouse gas emissions will be reduced by 33-35 percent compared to 2005 levels.
• Furthermore, non-fossil fuels would account for 40% of India's power capacity.
• Simultaneously, by 2030, India will have created an additional 'carbon sink' of 2.5 to 3 billion tonnes of CO2 equivalent through increased forest and tree cover.

International Solar Alliance

• ISA was launched on November 30, 2015, at the United Nations Climate Change Conference in Paris, in the presence of Mr. Ban Ki Moon, former Secretary-General of the United Nations.
• The primary goal of this process is to provide "clean and affordable energy" to the masses, which can then provide "sustainable security."
• Solar energy is an important component of Renewable Energy that is gaining attention from policymakers and scientists as an alternative source due to its greater "availability" and "affordability."
• The International Solar Alliance (ISA) is being formed at a time when there is a growing demand for Renewable Energy as an alternative source of energy on a global and regional scale.

Bharat Stage (BS) Emission Norms

• Vehicle emissions are one of the leading causes of air pollution, prompting the government to implement the BS 2000 (Bharat Stage 1) vehicle emission norms in April 2000, followed by BS-II in 2005.
• In 2010, BS-III went nationwide. However, in 2016, the government decided to follow global best practises and jump to BS-VI standards by skipping BS V entirely.

Conclusion

Many climate change solutions have the potential to provide economic benefits while also improving our lives and protecting the environment. Global frameworks and agreements, such as the Sustainable Development Goals, the UN Framework Convention on Climate Change, and the Paris Agreement, are also in place to guide progress. Switching from fossil fuels to renewables like solar and wind will reduce the emissions that are causing climate change. While a growing coalition of countries has committed to net zero emissions by 2050, roughly half of the emissions cuts must be implemented by 2030 in order to keep global warming below 1.5°C. Between 2020 and 2030, fossil fuel production must decline by about 6% per year.

FAQs

MCQs

1. Which of the following gases is considered a major contributor to the greenhouse effect?

A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Argon

2. What is the primary cause of the current trend in global climate change?

A) Volcanic eruptions
B) Solar radiation variations
C) Human activities
D) Natural climate cycles

3. Which sector is the largest source of greenhouse gas emissions globally?

A) Agriculture
B) Transportation
C) Industry
D) Energy production

4. Which international agreement aims to limit global warming to well below 2 degrees Celsius above pre-industrial levels?

A) Kyoto Protocol
B) Montreal Protocol
C) Paris Agreement
D) Rio Declaration

5. Which of the following is a potential consequence of ocean acidification?

A) Enhanced coral growth
B) Increased fish populations
C) Decreased shellfish populations
D) Stabilized sea levels

GS Mains Questions and Model Answers

Q1: Explain the impact of climate change on global food security. Provide examples to illustrate your answer.

Answer: Climate change poses a significant threat to global food security by affecting crop yields, altering growing seasons, and increasing the frequency of extreme weather events. Rising temperatures, prolonged droughts, and erratic rainfall patterns can lead to crop failures and reduced agricultural productivity. For example, prolonged heatwaves have negatively impacted wheat production in parts of India and Europe. Floods and cyclones can destroy crops and disrupt supply chains, leading to food scarcity and price spikes. Additionally, climate change exacerbates pest and disease outbreaks, further threatening crop health. Addressing these challenges requires climate-resilient agricultural practices, investment in irrigation infrastructure, and international cooperation to ensure stable food supplies.

Q2: Analyze the role of international agreements, such as the Paris Agreement, in combating climate change. Are they sufficient to achieve global climate goals?

Answer: International agreements like the Paris Agreement play a pivotal role in combating climate change by setting collective targets for reducing greenhouse gas emissions and limiting global warming to well below 2 degrees Celsius. The Paris Agreement encourages countries to set and update their Nationally Determined Contributions (NDCs), promoting global collaboration and accountability. However, its effectiveness depends on the commitment and action of individual nations. While progress has been made, significant challenges remain, including insufficient financial support, lack of enforcement mechanisms, and disparities in emissions reduction targets. Achieving global climate goals will require stronger commitments, enhanced technological cooperation, and more ambitious targets to bridge the gap between current efforts and the required reductions in emissions.

Q3: Discuss the role of renewable energy in mitigating climate change. What challenges need to be addressed to enhance its adoption?

Answer: Renewable energy plays a critical role in mitigating climate change by reducing greenhouse gas emissions from the energy sector, the largest contributor to global emissions. Solar, wind, and hydropower provide clean and sustainable alternatives to fossil fuels. The transition to renewable energy can lower carbon footprints, promote energy security, and create green jobs. However, several challenges hinder its widespread adoption, including high initial costs, technological limitations, intermittency issues, and inadequate infrastructure for energy storage and distribution. Addressing these challenges requires policy incentives, investments in research and development, grid modernization, and international cooperation to promote access to affordable clean energy solutions worldwide.

Previous Year Questions on Climate Change

1. UPSC CSE Prelims 2021:

Question: Which of the following is a major contributor to global warming?

A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Helium

Answer: (C)

Explanation: Carbon dioxide is a major greenhouse gas contributing to global warming through the greenhouse effect.

2. UPSC CSE Mains 2019 (GS Paper 3):

Question: "Critically analyze the role of international climate conferences in mitigating climate change and their impact on national policies."

Answer: International climate conferences, such as the Conference of the Parties (COP) under the United Nations Framework Convention on Climate Change (UNFCCC), provide a platform for nations to negotiate and adopt measures to combat climate change. These conferences foster global cooperation, set emission reduction targets, and encourage technological and financial support for developing countries. The agreements reached influence national policies, pushing governments to implement climate action plans, adopt renewable energy targets, and enhance resilience to climate change. However, the effectiveness of these conferences is often limited by political disagreements, insufficient enforcement mechanisms, and varying levels of commitment among participating nations. Stronger accountability measures and equitable support are needed to ensure meaningful progress in combating climate change.