Assignment Code: MEV-022/TMA/2020/2021-22

Course Code: MEV-022

Assignment Name: Impacts of Climate Change

Year: 2021-2022

Verification Status: Verified by Professor

Max. Marks: 100

Note: This assignment is based on the entire course.

Answer any five questions. All question carries equal marks. The marks for each question are indicated against it within brackets on the right-hand side.

Please write all answers in your own words.

Q1. Explain the direct and indirect effects of climate change on agriculture.

Ans) In India, the country's growing population poses a threat to the agricultural system's long-term viability. The increasing demand for food grain production and nutritious food items necessitates agricultural system reform. In addition, India's undernourished and malnourished population is becoming a serious problem. Agricultural production is also being harmed by a variety of biotic and abiotic challenges, including climate change. Indian agriculture is rainfed to a large part, and it is also reliant on groundwater. Another feature of Indian agriculture is resource-poor farmers who are particularly vulnerable to climate change. Increasing agricultural production in such circumstances is a monumental task.

Agriculture and related activities are a significant part of India's economy. However, because 62 percent of India's planted land is still reliant on rainfall, the country's agriculture remains fundamentally weather-dependent. In India, the effects of climate change on agriculture are critical. Because rural areas account for 75% of the population, agricultural success is intimately linked to poverty levels. In terms of the consequences of climate change on crop yields, overall food production, and welfare, the focus is on the two primary cereal crops - rice and wheat. Even with the favourable impacts of increased CO2 in the future, acute water shortage conditions paired with thermal stress could negatively influence wheat and, more severely, rice yield in India.

The following are the results of simulations of four different sites under various climate change scenarios for each crop:

1. The yields of both rice and wheat would decline as temperature levels rose while increasing as precipitation levels rose.

2. Increased CO2 concentrations in the atmosphere would benefit both crops by improving photosynthetic rates, radiation use efficiency, and water use efficiency.

3. Wheat would benefit more from increased CO2 levels than rice would.

   
   

Overall, the simulation suggests that temperature rise is going to have the following effects.

1. Positive effects of CO2 fertilisation, if any, are predicted to be offset by larger negative effects.

2. Rice could lose 13 percent to 22 percent of its net output under irrigation, compared to 16 percent to 34 percent for wheat.

3. Cotton, fruits, vegetables, tea, coffee, aromatic, and medicinal plants, as well as the nutritional quality of cereals and pulses, may all be damaged in some way.

The decrease in grain protein content in cereals could be linked to rising CO2 levels. Wheat yields in central India are expected to decline by up to 2% in the pessimistic scenario, while they might improve by up to 6% if the worldwide change is positive.

1. Changes in soil water resulting from global climate change may have an impact on all soil activities, including crop growth.

2. Increased evapotranspiration would come from a rise in temperature, potentially decreasing the groundwater table in some areas.

3. Increased temperature combined with decreased rainfall may cause upward water migration, resulting in salt build-up in the upper soil layers.

4. Coastal lands may be inundated with salt water as a result of rising sea levels and rising temperatures, rendering them unsuitable for conventional cultivation.

5. A 1°C increase in soil temperature may result in increased mineralization.

Q2. Describe the interaction between climate change and wetlands. How do wetlands play an important role in climate resilience?

Ans) Ecosystems provide a variety of providing (food and fibre), regulating (climate change and floods), cultural (recreational and aesthetic), and supporting (soil formation) services. Human health, livelihoods, nutritional and food security, social stability, and cohesion are all dependent on these services. While ecosystems in their natural state are generally more carbon dense and biologically diverse, degradation of many ecosystems is significantly reducing their carbon storage and sequestration capacity, resulting in increased greenhouse gas emissions and biodiversity loss at the genetic, species, and ecosystem level. Climate change is increasing the stress on ecosystems, as well as the consequences of other pressures such as habitat fragmentation, habitat loss and degradation, over-exploitation, invasive alien species, population pressure, and pollution.

Climate change is affecting the biosphere on a large and local scale, both in marine and terrestrial habitats, through biodiversity loss. It's generating changes in species distribution and ecosystems, as well as an elevated danger of extinction. Biodiversity, on the other hand, improves ecosystem resilience, which helps with both mitigation and adaptation to climate change. Climate change has already had an impact on biodiversity at the species and ecosystem levels, such as altering the timing of critical life events. Climate change is driving biodiversity to adapt through habitat shifts, life cycle alterations, or the emergence of new physical features. Climate change biology is a brand-new field dedicated to studying these shifts. Climate change is causing species ranges to alter. Changed species interactions have resulted in the most significant biotic changes as a result of climate change.

Few examples are:

1. All tropical reefs have seen coral bleaching, a change in the connection between corals and their symbiotic algae caused by high water temperatures.

2. A temperature-driven change in bark beetle emergence has produced massive tree mortality linked with bark beetle outbreaks. As a result of species range shifts or the repercussions of shifting relationships or phenology, entire ecosystems are being reorganised.

Biodiversity and healthy ecosystems, on the other hand, are significant resources for building resilience and minimising the risks and harms associated with climate change's negative effects. They can act as natural buffers against extreme climate and weather events such shifting rainfall patterns, droughts, storms, and other natural calamities. More choices for adjusting to a changing climate are available with diverse and integrated production systems. Ecosystem-based production systems limit the usage of synthetic inputs and the emissions of greenhouse gases that come with them. In the face of climate change, breeding drought-, salt-, and disease-resistant plant varieties, livestock breeds, and fish will become increasingly crucial to ensuring food security.

Habitat conservation and restoration projects promote biodiversity while also providing cost-effective and proven strategies for mitigating and adapting to climate change. Forests, rangelands, croplands, peat lands, and wetlands are all important carbon sinks on a worldwide scale. Many Intended Nationally Determined Contributions include their conservation, restoration, and sustainable use, making them a critical component of the Paris Agreement under the United Nations Framework Convention on Climate Change, a global commitment to mitigate dangerous changes in the Earth's atmospheric temperature and climate system.

Q3. Write short notes on the following:

a. Carbon dioxide fertilization effect

Ans) The atmosphere of the Earth is made up of a variety of gases. The two most abundant greenhouse gases in the atmosphere are water vapour and carbon dioxide. Although ecosystem reactions to temperature increases are diverse and complicated, both are transparent to visible incoming sunlight and trap heat emitted from the Earth's surface. According to reports, increased atmospheric carbon dioxide concentrations boost forest production and productivity due to the carbon dioxide fertilisation effect.

Long-term free-air CO2 enrichment (FACE) research found that in young tree stands, the average net primary productivity (NPP) increased by 23% under a 2 x CO2 climate scenario. It is a well-known fact that as CO2 concentration rises, plant growth rises as well. Warmer, more humid conditions have better forest productivity. Photosynthesis, the process by which green plants utilise sunlight for growth and development, requires carbon dioxide. An increase in atmospheric CO2 may enable trees to be more productive in conditions when water and nutrients are abundant, thereby changing the distribution of tree species. Tree growth will be greatest on nutrient-rich soils with plenty of water and will decline as fertility and water supplies decline.

Some factors, such as soil nitrogen availability, plant acclimation, and water availability, may alter the effect of CO2 on plant output. Plants will struggle to convert increased CO2 into organic matter production when nitrogen levels are low. Furthermore, in the long run, high CO2 levels may produce a build-up of carbohydrates in plant tissues, lowering photosynthetic rates or decreasing photosynthetic response to high CO2.

Despite the fact that deforestation contributes around 20% of greenhouse gas emissions, trees currently absorb more carbon than they emit. According to scientists, if the globe heats up to 2.5 degrees Celsius or more relative to pre-industrial levels, which is projected to happen very soon if emissions are not significantly decreased, this essential carbon-regulating service of forests could be lost totally. Furthermore, increased temperatures as a result of global warming, as well as protracted droughts, more intense insect invasions, and other environmental pressures that may accompany climate change, would result in significant forest damage and degradation.

Q3. b. Coral bleaching

Ans) Coral reefs are an important group of marine animals since they are home to roughly one-third of all marine life. Temperature (the ideal range is 22° to 29°C), nutrients, currents, turbidity, light, pH, calcium carbonate concentration, and other elements all influence coral reef growth and development. When it comes to temperature, coral reefs are extremely sensitive to changes in temperature. Corals eject the algae (zooxanthellae) living symbiotically in their tissues when the water temperature exceeds the optimum for coral growth, resulting in the bleached appearance of the corals. Coral bleaching is the term for this. The corals eventually die as a result of coral bleaching. Furthermore, acidification has a negative impact on coral skeletons by lowering calcification rates, delaying the thickening process, resulting in low skeleton density, and making them more vulnerable to breaking. However, the acidification effects vary by species, possibly due to differences in the organisms' ability to control the pH of their calcification sites.

1. Many marine species are likewise threatened by rising sea levels. Corals and sea grass meadows, for example, are threatened because they require relatively shallow water for photosynthesis. Rising sea levels also have an impact on a variety of marine animals. A good example is the Hawaiian Monk Seal. The population of monk seals is said to be falling at a rate of 4% per year.

2. Many marine creatures may be harmed by declining phytoplankton and krill populations.

Q4. Write short notes on the following:

a. Biofuels

Ans) Biofuels are made from plant-based materials. Today's biofuels are primarily ethanol from corn and sugarcane, which is combined with gasoline. Biodiesel, which is made from a range of crops such as soyabean, jatropha, and Pongamia, is mixed with diesel. Traditional biofuels, on the other hand, have modest climatic advantages because their manufacturing and processing are energy intensive across their entire lifecycle. However, new generation biofuels, which include waste-derived cellulosic feedstocks, agricultural residues, and energy crops produced on degraded lands, can reduce GHG emissions by 50-80%. As a result, biofuels should be evaluated in terms of lifecycle emissions. India is also expanding a biofuel programme based on non-edible tree crops cultivated on wasteland, such as jatropha. To protect food and environmental security, effective policy safeguards will be required.

On the other hand, energy plantation can result in significant land-use changes. Cropped land and forests can both be used to make biofuels. This could jeopardise food security. According to the Food and Agriculture Organization (FAO), this switchover will lead food prices to rise by 20 to 40% in the next ten years or so. Also, if forests are taken down to boost biofuel crop development, climate change will be accelerated. If biofuels are employed to help the world's poor transition to a non-fossil fuel-based energy future, they can be a part of the climate solution. The majority of Indian and African villages are not connected to the power grid. Biofuels can power their future instead of importing fossil fuels vast distances to feed these towns.

Q4. b. Ocean acidification

Ans) "The oceans absorb around 1/3 of the human CO2 produced into the atmosphere," according to the paper. CO2 can generate carbonic acid by interacting with water molecules as soon as it enters the water from the atmosphere, causing a shift in the concentrations of the hydrogen carbonate (HCO3 –) and carbonate (CO3 2–) ions. While this has considerably reduced global warming, it has also made the ocean more acidic, putting many marine species and ecosystems at risk. Ocean acidification has been shown to be 30 times greater than natural variation in the recent past.

Furthermore, during the industrial revolution, the mean surface ocean pH has declined by around 0.1 unit, resulting in a 25% rise in acidity, which is considerable. If current carbon dioxide emissions continue, ocean acidification levels are expected to rise by 144 percent by 2100. The ability of marine creatures like corals to generate calcium carbonate shells is severely hampered by increased acidity. Ocean acidification has been proven to affect calcium carbonate production in studies. Furthermore, ocean acidification exacerbates existing "physiological stressors," reducing the growth and survival rates of a small number of marine species, especially in their early phases of development.

Q5. Explain the impacts of climate change on energy sector.

Ans) Increasing energy usage causes a variety of environmental issues. Increased energy use, particularly the burning of fossil fuels, leads to an increase in greenhouse gas emissions. According to the Paris Agreement, we must take steps to restrict GHG emissions so that global mean surface temperature rises no more than 2 degrees Celsius above pre-industrial levels. We must take steps to "lower GHG emissions by 50-85 percent on 2000 levels by 2050" in order to meet the WB2C (well below 2°C) goal. According to the IPCC, in order to stabilise GHG emissions, global emissions must plateau and then decrease. We must be imaginative and adapt our energy consumption practises in order to meet the goals of the Paris Agreement.

It is a difficult task to reduce fossil fuel energy use. For example, despite the industrialised countries' pledge to cut CO2 emissions from 1990 levels under the Kyoto Protocol of the international climate convention, emissions have actually increased. Between 1990 and 2005, their emissions from energy-generating facilities increased by 24%, while their transportation emissions increased by 28%. When emissions must be reduced by 50-85%, emissions are still increasing. Because fossil fuel energy is very cheap and abundant, it is difficult to limit its use. Indeed, fossil fuels meet 80% of global primary energy demand, and it is predicted that their use would rise in the next 30 years, assuming that policies promoting "low carbon emissions" are aggressively advocated. With the energy sector accounting for over 60% of India's GHG emissions, there is a pressing need to encourage low-carbon emission technologies and approaches.

The energy sector is being impacted by a rise in the number of extreme climatic events and their severity. The impact on renewable energy systems is greater.

1. Solar Energy: Cloudiness has an impact on solar technology, and strong storms can destroy solar equipment. The efficiency of solar panels has decreased.

2. Damage to wind farms and distribution lines caused by wind energy.

3. Biomass Energy: Climate change has a negative impact on crop productivity and quality.

4. Hydropower: Hydropower generation output has decreased.

5. Coal Industry: During severe rains, the open mines filled with water, causing floods and landslides. Due to a lack of cooling water, the output of thermal power plants is reduced.

6. Tropical cyclones have potentially catastrophic impacts on offshore platforms and onshore infrastructure, resulting in increasingly frequent production interruptions in the oil and gas sector.

7. Higher temperatures and extreme weather events are likely to disrupt energy transmission infrastructure such as pipelines and electricity wires. Coastal floods, thawing permafrost in cold places, landslides, and fires caused by heat waves in hot regions are all threats to pipelines.

8. Heavy winds have an impact on power lines.

9. Substations are being flooded (land based).

10. Coastal floods cause inundation of sea water, which affects energy production sites and technologies, as well as transmission and distribution systems.

    
    

The cost of producing electricity has increased as a result of the dry weather. Hydropower generation in Africa fell by USD 83 billion, resulting in higher consumer costs.