Date:06-06-2022 Paper Solution | Global Warming and Climate Change

• Subject Code:3161312 
• Date:15-12-2022 
• Paper solved by Om sonawane

Q.1 

(a) Differentiate between Weather and Climate. 

Weather refers to the short-term conditions of the atmosphere at a particular location, such as temperature, precipitation, and wind. Climate, on the other hand, refers to the long-term patterns of weather in a specific region, including average temperature and precipitation, as well as extreme weather events. Climate is influenced by a wide range of factors, including solar radiation, ocean currents, and atmospheric circulation patterns, and can change over time. In other words, weather is what you experience outside on a day-to-day basis, while climate is a broad pattern of weather over an extended period of time. 

(b) Enlist and explain any one element of weather. 

One element of weather is temperature. Temperature is a measure of the amount of heat present in the atmosphere, and it can be measured in degrees Fahrenheit (F) or Celsius (C). Temperature affects the amount of water vapor in the air, which in turn affects cloud formation and precipitation. High temperatures can lead to increased evaporation and the formation of thunderstorms, while low temperatures can cause frost and freezing precipitation. Temperature also affects the movement of air masses, which can lead to the formation of high and low pressure systems, and can influence wind patterns.

In addition to this, temperature also plays a critical role in determining the climate of a region. Temperature is one of the key variables used to classify different types of climates, such as tropical, temperate, and polar. Changes in temperature can also have a significant impact on ecosystems and the distribution of plants and animals.

(c) Discuss the sources of methane and its climatic effects in detail.  

Methane (CH4) is a potent greenhouse gas that is released into the atmosphere from a variety of sources. Some of the main sources of methane include:

Agriculture: Methane is produced by the digestive process of ruminant animals such as cows, sheep, and goats, as well as by the decomposition of organic matter in rice paddies.

Natural Gas And Oil Systems: Methane is a primary component of natural gas, and leaks can occur during the extraction, transportation, and distribution of natural gas. Additionally, methane can be released during oil drilling and production.

Landfills: Methane is produced by the decomposition of organic matter in landfills.

Waste Water Treatment: Methane is produced by the breakdown of organic matter in waste water treatment plants.

Coal mining: Methane is released from coal mines, both during the mining process and from coal beds.

Biomass burning: Methane is released from fires, both natural and human-caused, that burn vegetation.

Methane has a warming effect on the atmosphere that is 28 times stronger than carbon dioxide over a 100-year period. This means that a given mass of methane has a much greater warming effect than the same mass of carbon dioxide. Methane is responsible for about 20% of the total radiative forcing of all greenhouse gases.

Methane also plays a role in the formation of ground-level ozone, a greenhouse gas and a major component of smog, that can harm human health and damage crops. 

Q.2 

(a) Define the following terms:

1. Short-lived climate forcers (SLCF) : 

Short-lived climate forcers (SLCF) refers to a group of greenhouse gases that have relatively short atmospheric lifetimes (typically less than a decade) compared to longer-lived greenhouse gases such as carbon dioxide (CO2). These gases include methane, black carbon, tropospheric ozone, and some industrial gases such as hydrofluorocarbons (HFCs) and sulfur hexafluoride (SF6). These gases contribute to climate change by trapping heat in the atmosphere, but they are removed relatively quickly from the atmosphere through various processes such as oxidation, deposition, and dilution.

Because of their short atmospheric lifetimes, SLCFs have the potential to provide more immediate climate benefits than reducing emissions of longer-lived greenhouse gases such as CO2, as the effects of reducing emissions of SLCFs would be felt within a few years to a decade.

However, SLCFs also have other negative environmental impacts besides their warming effects, such as particulate matter and smog, and hence reducing their emissions can also lead to co-benefits such as improved air quality and public health. 

2. Emission Trading : 

Emission trading, also known as cap-and-trade or carbon trading, is a policy tool used to reduce greenhouse gas emissions. The basic principle of emission trading is to place a cap, or limit, on the total amount of greenhouse gas emissions that can be produced by a certain sector or country. This cap is then divided into a set of allowances, each of which represents the right to emit a specific amount of greenhouse gas. These allowances can then be bought and sold in a market-based system.

Companies, organizations or governments that emit less than their allotted amount of greenhouse gases can sell their unused allowances to companies or organizations that emit more than their allotted amount. This creates a financial incentive for companies and organizations to reduce their emissions, as they can then sell their unused allowances and earn revenue. Emission trading can also help to reduce the overall cost of achieving emission reductions, by allowing companies and organizations to find the most cost-effective ways to reduce their emissions. 

Emission trading schemes can be either mandatory or voluntary. The most well-known mandatory scheme is the European Union Emissions Trading System (EU ETS) which is the first and largest emissions trading scheme in the world, covering power plants and heavy industries in the EU.

Voluntary schemes are mostly implemented by companies and organizations that are not covered by mandatory schemes, but want to reduce their emissions and demonstrate their environmental commitment. 

3. Climate Projection : 

Climate projection is the use of computer models to simulate the future state of the climate. These projections are based on scenarios of future greenhouse gas emissions, land use changes, and other factors that can affect the climate. The goal of climate projection is to provide information that can be used to assess the potential impacts of climate change and to develop strategies for adapting to and mitigating those impacts.

Climate projections are an important tool for understanding the potential impacts of climate change on a wide range of sectors, including agriculture, water resources, human health, and infrastructure. They are also used to inform policy decisions related to climate change, such as the development of emissions reduction targets and adaptation plans.

It's worth noting that Climate projction also known as Climate modeling, a set of mathematical equations and representations of physical processes that are used to simulate the interactions between the atmosphere, ocean, land surface, and ice. The models are based on our current understanding of the physical processes that govern the climate system, and they are run on powerful computers to simulate the future climate. 

(b) Discuss the role of IPCC and UNFCC. 

The Intergovernmental Panel on Climate Change (IPCC) is a scientific body established by the United Nations (UN) in 1988 to assess the state of knowledge on climate change. The IPCC's mission is to provide policymakers and the public with a clear and up-to-date view of the current scientific understanding of climate change, its causes, potential impacts, and options for mitigation and adaptation. The IPCC does not conduct its own research, but rather evaluates and synthesizes the findings of the scientific literature on climate change.

The IPCC produces a series of comprehensive assessment reports that are widely considered to be the most authoritative and comprehensive sources of information on climate change. These reports provide a detailed overview of the state of knowledge on climate change and are designed to be policy-relevant but not policy-prescriptive. The IPCC also produces special reports on specific topics, such as the impacts of climate change on oceans and cryosphere, and the land use, land-use change and forestry.

The United Nations Framework Convention on Climate Change (UNFCCC) is a treaty signed by 197 countries in 1992. The goal of the UNFCCC is to stabilize greenhouse gas concentrations in the atmosphere at a level that will prevent dangerous human interference with the climate system. To achieve this goal, the UNFCCC established a framework for negotiating international agreements to reduce greenhouse gas emissions.

The most significant outcome of the UNFCCC process so far is the 1997 Kyoto Protocol, which committed industrialized countries to specific emissions reductions. The Paris Agreement, adopted in 2015, which is an agreement under the UNFCCC to take action to combat climate change and strengthen the ability of countries to deal with its effects, and was ratified by 185 Parties, which is a legally binding agreement to reduce global emissions in order to keep the rise in global temperature below 2 degree Celsius.

The IPCC and UNFCCC work closely together, with the IPCC providing the scientific basis for the negotiations under the UNFCCC. The IPCC's assessment reports are considered to be the most authoritative source of information on climate change and are used by negotiators and policymakers as they work to develop and implement international agreements to address climate change.

(c) Explain earth's energy budget in detail. 

The Earth's energy budget is the balance between the energy that the Earth receives from the sun and the energy that it radiates back into space. The Earth's energy budget is closely linked to the climate, as changes in the balance of incoming and outgoing energy can cause the Earth's surface temperature to rise or fall.

The Earth receives energy from the sun in the form of shortwave radiation, which is mostly visible light and ultraviolet radiation. This energy is primarily absorbed by the Earth's surface, which warms up. The warmed surface then emits longwave radiation, which is mostly infrared radiation, back into the atmosphere. Some of this longwave radiation is absorbed by greenhouse gases in the atmosphere, such as carbon dioxide, methane, and water vapor, which causes the atmosphere to warm up as well.

The Earth also reflects some of the incoming shortwave radiation back into space, known as albedo, this reflectivity is influenced by the Earth's surface and clouds. This reflection cools the Earth's surface and helps to maintain the balance of the energy budget.

The balance between the incoming shortwave radiation and the outgoing longwave radiation is known as the radiative forcing. When the radiative forcing is positive, the Earth is absorbing more energy than it is radiating, which causes the Earth's surface and atmosphere to warm up. When the radiative forcing is negative, the Earth is radiating more energy than it is absorbing, which causes the Earth's surface and atmosphere to cool down.

The increase in greenhouse gases in the atmosphere, like carbon dioxide, has led to a positive radiative forcing, which has caused the Earth's surface temperature to rise. This is known as global warming, and is associated with an increase in the frequency and severity of extreme weather events, sea-level rise, and other changes in the climate.

Understanding the Earth's energy budget is important for understanding the causes and impacts of climate change. By monitoring the balance of incoming and outgoing energy, scientists can track changes in the Earth's climate and develop models to predict future changes in the climate. 

OR 

(c) Discuss the pathways to achieve the Kyoto target.   

The Kyoto Protocol is an international agreement that was adopted in 1997 under the United Nations Framework Convention on Climate Change (UNFCCC). The Protocol established legally binding emissions reduction targets for industrialized countries to reduce their greenhouse gas emissions in order to combat climate change. The Kyoto targets were agreed to reduce the emissions of six greenhouse gases: carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, hydrofluorocarbons, and perfluorocarbons.

There are several pathways to achieve the Kyoto targets, which include:

Emissions Trading: Under the Kyoto Protocol, countries that have emissions reduction targets can buy and sell emissions allowances in order to achieve their targets more efficiently and cost-effectively. This is known as the Clean Development Mechanism (CDM) and Joint Implementation (JI).

Renewable Energy: Increasing the use of renewable energy sources, such as solar, wind, and hydroelectric power, can help to reduce emissions by reducing the need for fossil fuels.

Energy Efficiency: Improving energy efficiency, such as through the use of more energy-efficient appliances and buildings, can help to reduce emissions by reducing the amount of energy that is needed to power homes and businesses.

Carbon capture and storage (CCS): CCS is a technology that captures carbon dioxide from power plants and other industrial sources, and then stores it underground so that it does not enter the atmosphere.

Forest Management: Forests absorb and store carbon, and sustainable forest management can help to reduce emissions by reducing deforestation and promoting reforestation.

Land-use changes: Land-use changes, such as changes in agricultural practices and urbanization, can affect the amount of carbon stored in the land, and sustainable land-use practices can help to reduce emissions.

Nuclear power : Some countries like France has achieved their Kyoto target by increasing the use of nuclear power, which does not emit greenhouse gases during operation.

It's worth noting that, The Kyoto Protocol's first commitment period ended in 2012, and its second commitment period, the Doha Amendment, has yet to enter into force. However, the Paris Agreement, adopted in 2015, which has been ratified by 185 Parties, which has set a goal to keep the global temperature rise to below 2 degree Celsius, and to pursue efforts to limit the temperature increase to 1.5 degrees Celsius above pre-industrial levels. 

Q.3 

(a) How anthropogenic activities exert cooling influence on earth's climate? 

Anthropogenic activities, such as the burning of fossil fuels and deforestation, can exert a cooling influence on Earth's climate by releasing particles into the atmosphere that reflect sunlight back into space. These particles, known as aerosols, can also absorb and re-emit heat energy, further cooling the planet. Additionally, the destruction of forests and other natural habitats reduces the amount of carbon dioxide and other greenhouse gases that are absorbed and stored by plants, leading to a decrease in the overall greenhouse effect and a cooling of the planet. 

(b) Classify the climate models.

Climate models can be broadly classified into two main categories:

General Circulation Models (GCMs): These models simulate the interactions between the atmosphere, oceans, land surface, and ice, and are often used to make long-term predictions about future climate change. GCMs are complex and computationally intensive, and require large amounts of data and powerful computers to run.

Earth System Models (ESMs): These models are similar to GCMs, but also include interactive components for other Earth system processes such as biogeochemical cycles. ESMs are even more complex and computationally intensive than GCMs.

Regional Climate Models (RCMs): These models are used to simulate the climate at a regional scale and make predictions about how climate change will affect specific areas. They are based on the output of GCMs or ESMs and use higher spatial resolutions.

Emission Scenario Models (ESMs) : These models simulate the future emissions of greenhouse gases and aerosols and their impact on climate. These models are used to explore the range of possible future climate change scenarios under different assumptions about future human activities.

Energy Balance Models (EBMs): These models are relatively simple and focus on the balance between incoming solar radiation and outgoing thermal radiation. They are used to understand the basic physics of climate change and make rough estimates of global temperature change. 

(c) Discuss Global Longitudinal Wind Pattern in detail. 

The Global Longitudinal Wind Pattern, also known as the "Hadley cell," is a large-scale atmospheric circulation pattern that is driven by the unequal heating of the Earth's surface. This pattern is characterized by rising air near the equator, where the sun's rays are most direct, and sinking air near the poles, where the sun's rays are least direct. The rising air near the equator creates low pressure areas, while the sinking air near the poles creates high pressure areas.

The rising air near the equator creates an area of low pressure and heat at the surface, which causes the air to expand and rise. As the air rises, it cools and loses moisture, creating an area of high pressure and dry weather known as the Intertropical Convergence Zone (ITCZ). The trade winds blow from east to west at the surface near the equator, which helps to distribute heat and moisture.

At around 30 degrees latitude, the rising air reaches the upper atmosphere, where it cools and sinks, creating an area of high pressure and dry weather known as the subtropical high-pressure belt. The sinking air at this latitude creates a warming effect, which causes the air to dry and create deserts such as the Sahara and the Atacama. The westerly winds at this level blow from west to east, which contribute to the formation of subtropical deserts.

As the sinking air at the subtropical high-pressure belt reaches the surface, it is warmed and compressed, creating a zone of high pressure and dry weather. The sinking air then flows poleward as a surface high-pressure system, forming the subtropical jet stream.

At the poles, the sinking air creates a zone of high pressure and cold weather, which is known as the polar high-pressure belt. The polar jet stream, which is a fast-moving ribbon of westerly winds, forms at the boundary between the polar high-pressure belt and the mid-latitude westerlies. The polar jet stream plays a significant role in the formation of weather patterns and storms in the mid-latitudes.

Overall, the Global Longitudinal Wind Pattern is a complex system that plays a key role in shaping the Earth's climate and weather patterns. It is driven by the unequal heating of the Earth's surface and the transfer of heat and moisture from the equator to the poles. 

Or Q.3 

1. Radiative Forcing : 

Radiative forcing is a measure of the change in the balance between incoming solar radiation and outgoing infrared radiation in the Earth's atmosphere. It is expressed in units of watts per square meter (W/m²). Positive radiative forcing leads to warming of the Earth's surface, while negative radiative forcing leads to cooling. Human activities, such as the burning of fossil fuels and deforestation, have led to positive radiative forcing and an increase in the Earth's average surface temperature. Climate change is caused by the increase in greenhouse gases, especially CO2, which leads to positive radiative forcing. 

2. ITCZ : 

The Intertropical Convergence Zone (ITCZ) is a band of low pressure and thunderstorms that circles the Earth near the equator. It is caused by the rising of warm, moist air near the equator and the sinking of cooler, dry air at higher latitudes. This rising and sinking of air creates a zone of convergence, or a place where the trade winds from the northern and southern hemispheres meet and push against each other. The ITCZ is also known as the "doldrums" or the "equatorial trough".

3. Carbon Capture and Sequestration (CCS) : 

Carbon Capture and Sequestration (CCS) is a technology used to reduce the amount of carbon dioxide (CO2) released into the atmosphere. It involves capturing CO2 from industrial and power generation sources, such as coal-fired power plants, and transporting it to a storage site, such as deep underground geological formations, where it is sequestered and not able to enter the atmosphere. CCS can also be used to capture CO2 from the air (DAC) and store it underground. The goal of CCS is to decrease greenhouse gas emissions and slow down the rate of climate change. CCS is still in the development and demonstration phase, and it's considered as one of the most promising technology for reducing emissions from the most carbon-intensive industries. 

(b) Differentiate between weather model and climate model. 

A weather model is a computer program that simulates the current and future state of the atmosphere, using mathematical equations and observational data. It aims to predict the specific weather conditions, such as temperature, precipitation, and wind, for a particular location and time period. Weather models are typically run for short-term forecasts, usually for a few days to a week ahead.

A climate model, on the other hand, is a computer program that simulates the long-term behavior of the Earth's climate system. It uses mathematical equations and observational data to estimate how the atmosphere, oceans, land surface, and ice will interact and change over time. Climate models are used to project future climate conditions, such as changes in temperature, precipitation, and sea level, for decades or even centuries ahead. Climate models are used to study the impacts of natural and human-induced changes on the Earth's climate, such as the effect of greenhouse gases on global warming. 

(c) Discuss Global Latitudinal Wind Pattern in detail.  

The global latitudinal wind pattern is the movement of air that is driven by the difference in temperature and pressure between the equator and the poles. This pattern is known as the "Hadley Cell" circulation, named after George Hadley, an English meteorologist who first described it in 1735.

The Hadley Cell circulation is characterized by rising air near the equator, where the sun's energy is most concentrated, and sinking air at about 30 degrees latitude in both the Northern and Southern Hemispheres. The rising air creates low pressure and causes the trade winds to blow towards the equator. As the air rises, it cools and condenses, forming clouds and precipitation. The sinking air at about 30 degrees latitude creates high pressure and causes the prevailing westerlies to blow towards the poles. As the air sinks, it warms and dries, resulting in clear skies and little precipitation.

Between the trade winds and the prevailing westerlies, there is a zone of easterly winds known as the Intertropical Convergence Zone (ITCZ) or the "doldrums", which are characterized by thunderstorms and light winds. The ITCZ is not fixed and moves north and south depending on the seasons.

At the poles, the cold and dry air sinks and creates high pressure, causing the polar easterlies to blow towards the equator.

This global latitudinal wind pattern is a major driver of the Earth's climate, influencing temperature, precipitation, and atmospheric circulation. It also plays a crucial role in the movement of ocean currents, which helps distribute heat around the planet.

It's worth noting that this pattern can change due to natural variability and human activities. For example, the warming of the poles due to climate change is causing the jet streams to shift, resulting in more extreme weather events in some regions. 

Q.4

Define the following terms:

1. Climate Sensitivity :

Climate sensitivity is a measure of how much the Earth's surface temperature will change in response to a change in the amount of greenhouse gases in the atmosphere. It is typically measured in units of degrees Celsius (°C) per doubling of atmospheric carbon dioxide (CO2) concentration. The most commonly cited value for climate sensitivity is 3°C, although there is a range of uncertainty around this value, with some estimates as low as 1.5°C and others as high as 4.5°C.

2. Climate feedback :

Climate feedback refers to the process by which changes in one aspect of the climate system (such as temperature, precipitation, or atmospheric composition) leads to changes in another aspect of the system, which in turn can amplify or dampen the initial change. Feedback mechanisms can be positive (amplifying) or negative (damping). An example of a positive feedback is the warming of the Arctic, which causes the loss of sea ice and the exposure of darker open water. This leads to more absorption of solar radiation, which in turn causes further warming, amplifying the initial warming. An example of a negative feedback is the increase in water vapor in the atmosphere as the planet warms, which leads to more clouds and more reflection of solar radiation, dampening the warming effect.

3. Representative Concentration Pathway (RCP) Scenario.

Representative Concentration Pathway (RCP) scenarios are a set of future greenhouse gas emission scenarios developed by the Intergovernmental Panel on Climate Change (IPCC) to provide a consistent framework for modeling and analyzing the potential impacts of climate change. These scenarios are based on different assumptions about future greenhouse gas emissions, land use change, and population growth.They are used to project the future concentration of greenhouse gases in the atmosphere and the resulting changes in temperature, precipitation, sea level rise, and other climate variables. There are four RCP scenarios: RCP2.6, RCP4.5, RCP6.0 and RCP8.5. RCP2.6 represents the scenario of aggressive mitigation and immediate action is taken to reduce emissions of greenhouse gases, while RCP8.5 represents a scenario of high emissions, with little or no action taken to reduce emissions.

(b) Discuss global ocean conveyor belt in detail.

The global ocean conveyor belt, also known as the oceanic thermohaline circulation, is a complex system of ocean currents that plays a major role in regulating the Earth's climate. It is driven by differences in temperature and salinity, which cause changes in water density that drive the circulation. The conveyor belt is made up of several major currents, including the Gulf Stream, the North Atlantic Drift, and the Kuroshio Current.

The conveyor belt begins in the North Atlantic, where cold, dense water sinks to the ocean floor, forming the North Atlantic Deep Water. This water then flows south along the ocean floor, eventually rising to the surface in the Southern Hemisphere. As it rises, it warms and picks up moisture, becoming less dense and flowing back towards the North Atlantic.

The Gulf Stream, which is a warm surface current, is the most well-known part of the conveyor belt. It flows from the Gulf of Mexico, up the East Coast of North America, and across the Atlantic towards Europe. The warm water in the Gulf Stream helps to keep Western Europe much warmer than it would be otherwise.

The conveyor belt also plays a crucial role in the global climate system, as it helps to redistribute heat around the Earth, affecting weather patterns and air temperatures. When the circulation slows down or stops, it can lead to changes in temperature and precipitation patterns, as well as sea level rise. The ocean conveyor belt is influenced by the atmospheric changes, such as the amount of greenhouse gases and the changes in the temperature and salinity of the ocean.

In summary, the global ocean conveyor belt is a complex system of ocean currents that plays a major role in regulating the Earth's climate by redistributing heat around the Earth, affecting weather patterns and air temperatures. It is driven by differences in temperature and salinity, which cause changes in water density that drive the circulation. The conveyor belt is made up of several major currents and its changes can have a big impact on the global climate system.

(C) Discuss the Global Carbon Cycle in detail.

The global carbon cycle is the process by which carbon moves between different reservoirs on Earth, including the atmosphere, oceans, land, and living organisms. The carbon cycle plays a crucial role in regulating the Earth's climate and maintaining the balance of life on Earth.

The carbon cycle starts with the process of photosynthesis, in which plants and other organisms use energy from the sun to convert carbon dioxide (CO2) from the atmosphere into organic compounds such as sugars and starches. These organic compounds are then used by plants as a source of energy and as building blocks for growth and reproduction.

The organic compounds produced by photosynthesis are then passed on to animals through the food chain, and when animals die, their bodies decompose, returning the carbon back to the soil and ocean. Some of the carbon is also stored in the form of fossil fuels, such as coal, oil, and natural gas, formed from the remains of ancient plants and animals.

The global carbon cycle is not a closed system, as human activities have greatly affected the balance of the carbon cycle. The burning of fossil fuels releases large amounts of CO2 into the atmosphere, which contributes to the greenhouse effect and global warming. Deforestation and land use change also affect the balance of the carbon cycle by releasing carbon stored in trees and soil into the atmosphere and reducing the capacity of the land to absorb CO2.

The oceans also play a significant role in the global carbon cycle. They absorb about 30% of the CO2 emitted into the atmosphere, which causes the acidification of the ocean water. This acidification affects the marine organisms and the balance of the ocean.

To regulate the global carbon cycle, reducing the emissions of CO2 and other greenhouse gases, increasing the storage of carbon in natural sinks, and developing new technologies to capture and store carbon are some of the solutions that have been proposed.

In summary, the global carbon cycle is the process by which carbon moves between different reservoirs on Earth, including the atmosphere, oceans, land, and living organisms. The carbon cycle plays a crucial role in regulating the Earth's climate and maintaining the balance of life on Earth. The human activities have greatly affected the balance of the carbon cycle, which in turn leads to changes in the climate and the impacts on the environment.To regulate the global carbon cycle, reducing the emissions of CO2 and other greenhouse gases, increasing the storage of carbon in natural sinks, and developing new technologies to capture and store carbon are some of the solutions that have been proposed.

OR Q.4 

(a) Discuss effect of climate change on Precipitation. 

Climate change is expected to have a significant impact on precipitation patterns around the world. In general, areas that are already dry are expected to become drier, and areas that receive a lot of precipitation are expected to receive even more. However, the specific effects of climate change on precipitation will vary depending on location.

In general, warming temperatures are expected to cause more evaporation, which can lead to increased precipitation in some areas. However, warmer air can also hold more water vapor, which can lead to more intense and frequent precipitation events, such as heavy rain or snowfall. This can cause flooding and landslides in some areas.

Climate change is also expected to lead to changes in atmospheric circulation patterns, which can affect where and when precipitation falls. This can lead to changes in the timing and amount of precipitation in different regions, which can have a significant impact on agriculture, water resources, and ecosystems.

Overall, climate change is expected to lead to more extreme and variable precipitation patterns, which can have significant impacts on people and the environment.

(b) Discuss the indications of global warming.

There are several indications of global warming that scientists have observed and continue to study. Some of the main indications include:

Rising Temperatures: One of the most obvious indications of global warming is the increase in average global temperatures. Since the late 19th century, the Earth's average surface temperature has increased by about 1.8 degrees Fahrenheit (1 degree Celsius).

Melting Ice: Another indication of global warming is the melting of ice on land and in the oceans. This includes the melting of glaciers, ice sheets, and sea ice. The melting of ice can contribute to sea level rise and can also affect wildlife and local communities.

Changing Precipitation Patterns: Global warming can also lead to changes in precipitation patterns, such as more intense and frequent precipitation events or longer periods of drought.

Rising sea levels: As the Earth's temperature rises, the oceans warm and expand, causing sea levels to rise. This can lead to coastal flooding and erosion.

Increasing frequency and severity of extreme weather events: The warming of the planet has been linked to an increase in the number of extreme weather events such as heatwaves, droughts, floods and storms.

Changes in ecosystems: Global warming can also lead to changes in ecosystems, such as shifts in the range of plants and animals, changes in the timing of seasonal events, and changes in the productivity of ecosystems.

These indications are supported by a large body of scientific evidence, and are consistent with the basic physics of the greenhouse effect. 

(c) Discuss the GHG emission mitigation action. 

GHG emission mitigation refers to actions taken to reduce or prevent the release of greenhouse gases (GHGs) into the atmosphere. These actions can include, but are not limited to:

• Increasing energy efficiency and conservation
• Increasing the use of renewable energy sources
• Implementing carbon pricing mechanisms
• Investing in carbon capture and storage technology
• Changing land use practices to reduce deforestation and promote reforestation
• Encouraging sustainable transportation options

Implementing regulations and standards to limit emissions from various sectors such as industry and agriculture. 

These actions can be implemented at various levels, including by individuals, businesses, and governments. The Paris Agreement, adopted in 2015, aims to strengthen the ability of countries to deal with the impacts of climate change by keeping a global temperature rise this century well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius.

Q.5 

(a) How do greenhouse gases such as carbon dioxide cause global warming?

Greenhouse gases, such as carbon dioxide, trap heat from the sun in the Earth's atmosphere, which causes the Earth's surface to warm up. This is known as the greenhouse effect.

When the sun's energy reaches the Earth's atmosphere, some of it is reflected back to space, while the rest is absorbed by the Earth's surface. The absorbed energy warms the surface, and some of it is then radiated back into the atmosphere as infrared radiation. Greenhouse gases, such as carbon dioxide, absorb this infrared radiation, trapping the heat in the atmosphere. This causes the Earth's surface to warm up, leading to an increase in global temperatures, which is known as global warming.

The increase in atmospheric concentration of greenhouse gases, particularly carbon dioxide, is the primary driver of global warming. The burning of fossil fuels (such as coal, oil, and gas) for energy is the largest source of human-caused carbon dioxide emissions, but deforestation, agriculture and other human activity also release these gases. As the Earth's surface warms, it can cause a range of impacts including sea level rise, more intense heatwaves and storms, changes in precipitation patterns and more. 

(b) Discuss effect of climate change on agriculture and food production.

Climate change can have a significant effect on agriculture and food production. Some of the key impacts include:

Changes in temperature and precipitation patterns can affect crop growth and yields. For example, heatwaves can stress crops, and droughts can reduce soil moisture, leading to lower crop yields. 

Changes in precipitation patterns can also affect soil moisture, which can be detrimental to crop growth. 

Increased frequency and severity of extreme weather events, such as floods and storms, can damage crops and infrastructure, leading to reduced yields and higher costs for farmers.

Rising temperatures can also affect the distribution and abundance of pests and diseases, which can further reduce crop yields.

Changes in temperature and precipitation patterns can also affect the timing of plant growth, which can disrupt the synchrony between crops and their pollinators, leading to reduced crop yields. 

These impacts can lead to reduced food availability and food insecurity, particularly in regions that are already food insecure. Climate change can also lead to changes in the types of crops that can be grown in different regions, as well as changes in the way food is produced. For example, farmers may need to shift to drought-resistant crops, or adopt new irrigation methods to adapt to changing water availability.

It's worth noting that agriculture itself is also a significant source of greenhouse gas emissions, particularly from enteric fermentation in domesticated animals and manure management, and from synthetic fertilizer use. Therefore, sustainable agriculture practices that reduces emissions and sequester carbon, such as agroforestry, conservation agriculture, precision agriculture, can play a role in mitigating climate change. 

(c) Discuss the Impacts of 1.5°C and 2°C of Warming.

The impacts of 1.5°C and 2°C of warming are significant and far-reaching. Some of the key impacts include:

At 1.5°C of warming, the Arctic Ocean will be nearly ice-free in the summer, and sea levels will have risen by about 26 centimeters (10 inches) or more, potentially displacing millions of people living in low-lying areas.

At 2°C of warming, sea levels could rise by up to 2 meters (about 6.5 feet) or more, putting many coastal cities and low-lying islands at risk of severe flooding and erosion.

At 1.5°C of warming, coral reefs will be largely lost, and many marine species will be at risk of extinction. At 2°C of warming, the majority of coral reefs will be lost, and it is estimated that around 30% of marine species will be at risk of extinction.

At 1.5°C of warming, there will still be an increased risk of heatwaves, droughts, and heavy precipitation. At 2°C of warming, these risks will be even greater, with more frequent and severe heatwaves, droughts, and heavy precipitation events.

At 1.5°C of warming, many land-based species will be at risk of extinction, and ecosystems will be severely impacted. At 2°C of warming, the risk of extinction for many species will be even greater, and many ecosystems will be irreversibly altered.

At 1.5°C of warming, crop yields will decline, and food security will be at risk. At 2°C of warming, these risks will be even greater, with more severe declines in crop yields and increased food insecurity in many regions.

At 1.5°C and 2°C of warming, the risk of extreme weather events, such as floods, droughts, and storms, will increase, leading to more damage to infrastructure and increased economic costs.

It's worth noting that many regions will be more affected by these impacts and may suffer more severe consequences. Therefore, it's crucial to limit global warming to well below 2°C, and pursue efforts to limit warming to 1.5°C, in order to reduce the risks and impacts of climate change. 

OR Q.5

1. Thermohaline circulation :

Thermohaline circulation (THC) is a large-scale ocean circulation pattern driven by differences in water density, which is primarily determined by temperature (thermo) and salinity (haline). Warm water is less dense and tends to rise, while cold and salty water is more dense and sinks. This creates a global ocean conveyor belt that helps to distribute heat and nutrients aound the planet. The THC plays a critical role in regulating the Earth's climate and supporting marine ecosystems.

2. Gulf stream :

The Gulf Stream is a powerful ocean current that flows from the Gulf of Mexico to the Atlantic Ocean. It is driven by differences in temperature and salinity between the warmer, saltier waters of the Gulf of Mexico and the cooler, fresher waters of the Atlantic Ocean. The Gulf Stream is responsible for bringing warm water and air to the northeastern United States and Europe, and it plays a crucial role in the global ocean circulation system. It also helps to moderate the climates of the regions it passes through, making them milder and more temperate than they would be without it.

3. Ocean current :

Ocean current refers to the continuous movement of water in the ocean, caused by a combination of factors such as wind, tides, and differences in water temperature and salinity. These currents can flow in various directions and at different speeds, and can have a significant impact on weather patterns, marine life, and human activities such as shipping and fishing. Some examples of ocean currents include the Gulf Stream, the California Current, and the Kuroshio Current.

(B) Enlist and explain any one components of a climate model.

One component of a climate model is the atmospheric component. This component simulates the physical processes that govern the behavior of the atmosphere, such as the movement of air masses, the formation of clouds and precipitation, and the exchange of heat and moisture between the atmosphere and the surface.The atmospheric component typically includes a number of sub-components, such as a dynamic core that simulates the movement of air masses, a radiation core that simulates the exchange of energy between the atmosphere and the sun, and a physical parameterization scheme that describes the microphysical processes that govern the formation of clouds and precipitation.The atmospheric component also typically includes a representation of the Earth's surface, such as land, oceans and sea ice, which are important for the exchange of heat and moisture between the atmosphere and the surface. These components work together to simulate the behavior of the atmosphere and how it interacts with the other components of the climate system, such as the oceans, land surface and cryosphere.

(C) Define and discuss the pathways for Carbon Dioxide Removal (CDR) and Negative Emissions. 

Carbon Dioxide Removal (CDR) and Negative Emissions refer to a set of technologies and techniques that aim to actively remove carbon dioxide (CO2) from the atmosphere, in order to mitigate the effects of climate change. These techniques can be grouped into four main categories:

Biological CDR: This includes techniques such as afforestation, reforestation, and bioenergy with carbon capture and storage (BECCS), where plants and trees absorb CO2 through photosynthesis, and the CO2 is then stored in the biomass or in underground storage.

Carbon Mineralization: This process involves the conversion of CO2 into solid carbonates through chemical reactions with minerals, such as in the process of Direct Air Capture (DAC) which captures CO2 from the air and converts it into solid carbonates.

Ocean Fertilization: This technique involves the addition of nutrients such as iron to the ocean, which stimulates the growth of phytoplankton, which in turn absorb CO2 through photosynthesis.

Enhanced Weathering: This method involves the acceleration of natural weathering processes, such as the weathering of silicate rocks, which also converts CO2 into solid carbonates.

Negative emissions refer to the overall net removal of CO2 from the atmosphere by these CDR techniques. It is important to note that these techniques are still in the development stage and their scalability, cost-effectiveness and environmental impacts are still under investigation. Moreover, CDR and negative emissions are not considered as a substitute for reducing carbon emissions at their source but rather as a complementary approach to mitigate the effects of the historical emissions.