--- title: "Climate change gases, mitigation and international efforts" subject: "Technology, Environment and Society" chapter: 6 key: "semester_7/technology_environment_and_society:cc-gases-international-efforts" source: https://www.bctengineer.com/q/semester_7/technology_environment_and_society/cc-gases-international-efforts site: BCT Engineering --- # Climate change gases, mitigation and international efforts Technology, Environment and Society · Chapter 6: Climate Change - Asked in: 2074 Asoj, 8 marks - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_7/technology_environment_and_society/cc-gases-international-efforts - Whole chapter: https://www.bctengineer.com/md/semester_7/technology_environment_and_society/chapter-6 ## Question What are climate change gases? Write down its mitigation measures. Also explain international efforts to tackle its problem. ## Short answer Climate change gases are greenhouse gases absorbing and re-emitting infrared heat, mainly CO2, methane, N2O, halocarbons and SF6. Mitigation means cutting emissions: clean energy, efficiency, clean transport, forests, agriculture, waste, industry, carbon pricing and lifestyle change. International efforts: IPCC (1988), UNFCCC (1992), Kyoto Protocol (1997), Paris Agreement (2015, below 2 deg C), Glasgow, COP27/28 loss and damage fund, COP29 300 billion by 2035. ## Answer **Climate change gases** (greenhouse gases) are atmospheric gases that absorb infrared heat emitted by the Earth's surface and re-radiate it back, causing the greenhouse effect. Human activities have increased them sharply since the Industrial Revolution, causing global warming and climate change. | Gas | Main sources | GWP (100 yr, IPCC AR5) | Lifetime | |---|---|---|---| | Carbon dioxide (CO₂) | Burning coal, oil, gas; deforestation; cement | 1 | Centuries | | Methane (CH₄) | Paddy fields, livestock, landfills, gas leaks | 28 | ~12 years | | Nitrous oxide (N₂O) | Nitrogen fertilisers, manure, burning | 265 | ~120 years | | CFCs / HCFCs / HFCs | Refrigerators, ACs, aerosols, foams | Thousands | Decades–centuries | | Sulphur hexafluoride (SF₆) | Switchgear insulation | ~23,500 | ~3,200 years | | Water vapour (H₂O) | Evaporation (feedback, not directly emitted) | – | Days | | Tropospheric ozone (O₃) | Formed from NOₓ and VOCs from vehicles | – | Weeks | #### Mitigation measures Mitigation means cutting GHG emissions at the source or increasing sinks that absorb them. - **Clean energy:** expand hydropower, solar, wind and micro-hydro; phase down coal, oil and gas. - **Energy efficiency:** LED lights, efficient motors, better building insulation, energy audits in industry. - **Clean transport:** electric vehicles and electric public transport, cable cars, non-motorised transport (cycling, walking). - **Forests and land:** stop deforestation, plant trees, community forestry, REDD+ (Reducing Emissions from Deforestation and Forest Degradation). - **Agriculture:** less chemical fertiliser, organic farming, better manure handling, improved paddy water management. - **Waste:** reduce, reuse, recycle; capture landfill methane; biogas from kitchen and animal waste. - **Industry:** cleaner production, replacing old brick kilns with zig-zag kilns, low-carbon cement. - **Carbon pricing and policy:** carbon tax, emissions trading, removing fossil fuel subsidies. - **Awareness and lifestyle:** saving energy, less food waste, using public transport. #### International efforts to tackle climate change | Year | Effort | Key point | |---|---|---| | 1988 | IPCC formed (by WMO and UNEP) | Scientific assessment of climate change | | 1992 | UNFCCC adopted at Rio Earth Summit | Goal: stabilise GHG concentrations; COPs held every year | | 1997 | Kyoto Protocol (in force 2005) | Binding cuts for developed (Annex I) countries; CDM, emission trading | | 2009 | Copenhagen Accord (COP15) | Pledge of US\$100 billion per year of climate finance by 2020 | | 2015 | Paris Agreement (COP21, in force 2016) | Keep warming well below 2 °C, try for 1.5 °C; every country submits NDCs | | 2021 | Glasgow Climate Pact (COP26) | "Phase down" of unabated coal; stronger NDCs | | 2022–23 | COP27, COP28 | Loss and Damage Fund created and made operational; first Global Stocktake | | 2024 | COP29, Baku | New climate finance goal of US\$300 billion per year by 2035 | Key features of these efforts: - **UNFCCC (1992):** framework treaty, principle of **"common but differentiated responsibilities"** – developed countries, which emitted most in the past, should lead. - **Kyoto Protocol (1997):** first legally binding targets; developed countries to cut emissions by an average of about 5% below 1990 levels in 2008–2012. Introduced flexible mechanisms – **Clean Development Mechanism (CDM)**, Joint Implementation and Emission Trading. Nepal's biogas programme earned carbon credits under CDM. - **Paris Agreement (2015):** all countries, rich and poor, set their own **Nationally Determined Contributions (NDCs)**, update them every five years and report progress; Global Stocktake every five years. - **Climate finance:** Green Climate Fund, Adaptation Fund, Least Developed Countries Fund, and the new Loss and Damage Fund. - **Other agreements:** Montreal Protocol (1987) and its Kigali Amendment (2016) phase out CFCs and HFCs. Nepal is a party to the UNFCCC, Kyoto Protocol and Paris Agreement. It has prepared NAPA (2010), LAPA (2011), the National Climate Change Policy (2019), its second NDC (2020), the National Adaptation Plan (2021) and a Long-Term Strategy for Net-Zero Emissions (2021), which sets a target of **net-zero emissions by 2045**. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What does the UNFCCC principle of 'common but differentiated responsibilities' mean? A. Every country has an identical target B. Only poor countries must act C. Developed countries, which emitted most in the past, should lead D. No country has any responsibility Answer: C. All share the problem, but historic emitters (developed countries) should lead the cuts. (Key point: Meaning of CBDR) 2. What did the Kyoto Protocol introduce? A. NDCs for all countries B. Binding targets for developed countries and flexible mechanisms: CDM, Joint Implementation and Emission Trading C. The Loss and Damage Fund D. The Montreal Protocol Answer: B. Kyoto gave the first legally binding targets (about 5% below 1990 levels in 2008-2012) and market mechanisms such as CDM. (Key point: Kyoto mechanisms) 3. How does the Paris Agreement differ from Kyoto in its approach? A. Only developed countries set binding targets B. All countries set their own NDCs, updated every five years with a Global Stocktake C. It has no reporting D. It only deals with CFCs Answer: B. Paris involves all countries submitting self-determined NDCs with reporting and a five-yearly stocktake. (Key point: Paris NDCs) 4. Which is a climate finance mechanism listed in the answer? A. IPCC B. Green Climate Fund, Adaptation Fund, LDC Fund and the Loss and Damage Fund C. Kigali Amendment D. Montreal Protocol Answer: B. These funds channel finance to developing countries; the IPCC is a scientific body and the others are treaties. (Key point: Climate finance) ## Related in Technology, Environment and Society - [Climate change impacts in Nepal and international efforts](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Acc-impacts-nepal-international) — Technology, Environment and Society, chapter 6 - [Climate change gases, impact and mitigation](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Acc-gases-impact-mitigation) — Technology, Environment and Society, chapter 6 - [Human-induced climate change and international efforts](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Ahuman-induced-cc-international) — Technology, Environment and Society, chapter 6 - [Short note: International efforts to mitigate climate change](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Ainternational-efforts-note) — Technology, Environment and Society, chapter 6 - [Climate, weather and international efforts](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Aclimate-weather-international) — Technology, Environment and Society, chapter 6 - [Climate change gases and mitigation interventions](https://www.bctengineer.com/question.md?key=semester_7%2Ftechnology_environment_and_society%3Acc-gases-interventions) — Technology, Environment and Society, chapter 6 ## Related in other subjects - [Climate change and renewable mitigation](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Aclimate-change-renewables-mitigation) — Energy Environment and Society, chapter 4 - [Greenhouse gases and global control efforts](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Agreenhouse-gases-efforts) — Engineering Chemistry, chapter 3 - [Mitigation measures of erosion](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Aerosion-mitigation) — Engineering Geology II, chapter 5 - [Biogas routes and climate change](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Abiogas-routes-climate-change) — Energy Environment and Society, chapter 3