1️⃣1️⃣ தரம் 11 · அலகு 8
காலநிலை மாற்றங்கள்
★★★★☆
பசுமைக்குடில் விளைவுவெப்பமயமாதல்
\"இந்த வருடம் வாதம் வேறு\" — மழை தாமதம் ஆனது, கோடை இரவில் கூட வெக்கையாக இருக்கிறது, மலையோர குளிர் குறைகிறது — தாத்தா-பாட்டி சொல்வதில் தத்துவம் உண்டா? Climate Change (காலநிலை மாற்றம்) என்பது தனியான ஒரு செய்தி அல்ல — இது 20-ம் நூற்றாண்டிலிருந்து புவியின் சராசரி வெப்பநிலை + காலநிலை patterns மாறிக் கொண்டிருக்கிறது — and தற்போது வேகமாக. காரணம் முக்கியமாக மனிதனின் தொழில்மயமாதல், வாகனம், காடழிப்பு — இவை வளி மண்டலத்திற்கு Greenhouse Gases (GHG) கொட்டுகின்றன. இந்த அலகில் (1) காலநிலை vs வானிலை, (2) Greenhouse effect, (3) காரணங்கள், (4) விளைவுகள், (5) Paris Agreement + சர்வதேச நடவடிக்கைகள், (6) SL impact பார்ப்போம்.
1. Weather vs Climate vs Climate Change
அடிக்கடி குழப்பப்படும் மூன்று வேறுபட்ட concepts:
- Weather (வானிலை): குறிப்பிட்ட நேரத்தில் + இடத்தில் வளி மண்டலத்தின் நிலை — temperature, rainfall, humidity, wind. காலம்: minutes/hours/days. \"இன்று மாலை மழை வரும்\".
- Climate (காலநிலை): ஒரு பகுதியின் 30 ஆண்டுச் சராசரி weather. காலம்: decades+. \"நுவரெலியா குளிராக இருக்கும்\".
- Climate Change (காலநிலை மாற்றம்): 30+ ஆண்டுகளில் காலநிலையின் நிலையான மாற்றம் — typically gradual. தற்போது anthropogenic (மனித-induced) காரணமாக rapid.
Natural vs Anthropogenic
- Natural climate change — இயற்கையான variability + cycles. Ice ages, Milankovitch cycles (puvi axis tilt + orbit eccentricity), volcanic eruptions, solar cycles. Time scale: thousands-millions of years.
- Anthropogenic climate change — மனிதனின் செயற்பாடுகளால் — fossil fuel + deforestation + industry + agriculture. Time scale: ~200 years (since Industrial Revolution).
2. Greenhouse Effect — காலநிலை மாற்றத்தின் இயக்கம்
Natural Greenhouse Effect
புவியின் வளி மண்டலத்தில் இயற்கையாக சில greenhouse gases — H₂O, CO₂, CH₄, N₂O — உள்ளன. சூரியன் இலிருந்து short-wave radiation (UV + visible light) கீழே வந்து புவியை வெப்பப்படுத்தும். புவி அந்த வெப்பத்தை long-wave infrared radiation-ஆக மீண்டும் வெளிவிடும். GHGs அவற்றை trap செய்து — atmosphere warm-ஆக வைக்கின்றன.
Natural greenhouse effect இல்லாமல் புவியின் சராசரி temperature ~-18°C ஆக இருந்து வாழ்க்கைக்கு cold முடியாதது. ஆனால் GHG-களின் இயற்கை அளவில் — temperature ~+15°C. அதனாலேயே greenhouse effect = வாழ்வாதார அவசியம்.
Enhanced Greenhouse Effect — Problem
மனிதனின் activity-ஆல் atmosphere-இல் extra GHG கொட்டப்படுவதால் — heat trapping increases → global warming. Industrial Revolution முதல் CO₂ ~280 ppm → 425+ ppm (2024) என உயர்ந்தது (50%+ அதிகம்). புவி சராசரி temperature ~1.1°C அதிகரித்துள்ளது.
Main Greenhouse Gases + GWP
GWP (Global Warming Potential) = CO₂-ஐ விட எவ்வளவு stronger over 100 years.
| Gas | Source | GWP (100yr) | Atmospheric lifetime |
|---|---|---|---|
| CO₂ | Fossil fuels, deforestation, cement | 1 (baseline) | ~100-1000 yrs |
| Methane (CH₄) | Livestock, rice paddies, landfills, gas leaks | ~84 | ~12 yrs |
| Nitrous oxide (N₂O) | Fertilizers, soil microbes, industry | ~273 | ~114 yrs |
| F-gases (HFC, PFC, SF₆) | Refrigeration, electronics | 1,000-23,000 | varies |
| Water vapor (H₂O) | Natural; amplifies warming | — | days |
CO₂ = primary culprit (~75% emissions). Methane = significant short-term impact. Net-zero target focuses on CO₂ + methane reduction.
3. Anthropogenic Causes
(அ) Energy Sector — ~75% of GHG
- Electricity + heat generation: coal + gas + oil power plants. China, India, USA top emitters.
- Transport: cars, trucks, aviation, shipping. 20% global emissions.
- Industry: steel, cement, chemicals, manufacturing.
- Buildings: heating, air conditioning, lighting.
(ஆ) Agriculture + Land Use ~20%
- Livestock (cattle): methane belching; ~14% global GHG.
- Rice paddies: anaerobic methane.
- Fertilizers: N₂O from soil.
- Deforestation: reduces carbon sinks + releases stored carbon. Amazon, Congo, Indonesia.
- Land degradation: overgrazing, soil loss.
(இ) Industry + Waste ~5%
- Cement production (CaCO₃ → CaO + CO₂).
- Steel + aluminium smelting.
- F-gases from refrigeration.
- Landfill methane.
- Wastewater.
Cumulative emitters (1850-2023)
- USA ~25% historical cumulative.
- China ~14% (recent surge but cumulative still less than USA).
- EU ~17%.
- Russia ~7%.
- Africa ~3%.
Per-capita emissions (2024)
- Qatar 37 tons CO₂/person highest.
- USA 14 tons.
- China 7.5 tons.
- EU 6 tons.
- India 1.9 tons.
- Sri Lanka ~1 ton.
- Burundi 0.05 tons.
4. Observed Effects + Projections
Temperature
- Global mean surface temperature +1.1°C above pre-industrial (1850-1900 baseline) by 2024.
- Each of last 10 years among hottest on record.
- 2023, 2024 hottest years recorded.
- Arctic warming 2-3x global average.
Cryosphere (Ice + Snow)
- Arctic sea ice declining ~13% per decade since 1979. Could be ice-free in summer by 2050.
- Greenland ice sheet losing 280 billion tons/year.
- Antarctica losing ice increasing rate.
- Mountain glaciers retreating worldwide (Himalayas, Alps, Andes, Africa).
- Permafrost thawing — releases stored methane (positive feedback).
Sea Level Rise
- +25 cm since 1900; accelerating.
- +30-100 cm projected by 2100 depending on emissions.
- Threatens coastal cities (Mumbai, Jakarta, Shanghai, Colombo, NYC, Miami).
- Submergence of small island states (Maldives, Tuvalu, Marshall Islands).
Extreme Weather
- More intense + frequent heatwaves (Europe 2003 + 2022; India 2023).
- More intense cyclones/hurricanes (Cat 4-5 fraction rising).
- More intense rainfall events + flooding.
- More droughts (California, Horn of Africa).
- More wildfires (Australia 2019-20, California, Canada 2023).
Ecological Impact
- Coral bleaching — Great Barrier Reef mass events 2016, 2017, 2020, 2024.
- Species range shifts — polar species disappearing.
- Phenology disruption — flowers blooming earlier, bird migration mismatch.
- Mass extinction acceleration.
- Food security — crop yields stressed.
Human Impact
- Heat-related deaths rising globally.
- Climate migration — 100M+ projected by 2050.
- Disease range expansion (malaria, dengue).
- Water stress in 2B+ people.
- Climate conflicts (Darfur, Syria drought-linked).
5. International Response
UNFCCC + COP
- UNFCCC (UN Framework Convention on Climate Change) — 1992 Rio Earth Summit; ~196 parties.
- COP (Conference of Parties) — annual meeting; COP29 Baku 2024.
- IPCC (Intergovernmental Panel on Climate Change) — established 1988; scientific assessment; Nobel Peace 2007.
Kyoto Protocol (1997)
- Binding emission targets for developed countries only.
- 5% reduction below 1990 levels by 2008-12.
- Limited success; USA never ratified; China + India not bound.
Paris Agreement (2015, COP21)
- Universal — all 196 parties commit.
- Limit warming to "well below 2°C", pursue 1.5°C above pre-industrial.
- Nationally Determined Contributions (NDCs) — voluntary; reviewed every 5 years.
- $100 billion/year climate finance developed → developing (long undermet).
- Net-zero by mid-century — most developed countries 2050; China 2060; India 2070.
- USA briefly withdrew 2017-21; rejoined under Biden.
Recent COPs
- COP21 Paris 2015 — Paris Agreement.
- COP26 Glasgow 2021 — coal phase-down language; methane pledge.
- COP27 Sharm El-Sheikh 2022 — Loss & Damage fund agreed.
- COP28 Dubai 2023 — first explicit "transition away from fossil fuels."
- COP29 Baku 2024 — climate finance $300B/yr.
Other
- Montreal Protocol 1987 — CFC ban; ozone layer recovering (most successful environmental treaty).
- SDG 13 (Climate Action).
- Net-Zero alliances — Race to Zero (UN); GFANZ (finance).
6. Mitigation + Adaptation
Mitigation (குறைப்பு)
GHG emissions reduce செய்வது + carbon removal.
- Renewable energy — solar, wind, hydro, geothermal, biomass.
- Electric vehicles (EVs) + public transport + cycling.
- Energy efficiency — appliances, buildings, industry.
- Carbon pricing — taxes, cap-and-trade (EU ETS).
- Reforestation + afforestation.
- Sustainable agriculture — reduced fertilizer, no-till, organic.
- Methane reduction — gas leak monitoring, livestock diet.
- Carbon capture & storage (CCS) + Direct air capture (DAC).
- Green hydrogen — for heavy industry + shipping + aviation.
- Net-zero finance — ESG, green bonds.
Adaptation (தற்காப்பு)
Unavoidable impacts-ஐ எதிர்நோக்கி resilience கட்டுவது.
- Coastal protection — sea walls, mangroves, dunes.
- Climate-resilient agriculture — drought-tolerant crops, drip irrigation.
- Water management — rainwater harvesting, desalination.
- Disaster preparedness — early warning + evacuation.
- Infrastructure — heat-resistant cities, urban green.
- Health systems — vector control + heatwave plans.
- Climate-smart insurance.
- Climate refugees support.
7. Sri Lanka & Climate Change
SL Vulnerability
SL = tropical island + 1,340 km coast + agriculture-dependent + climate-sensitive economy → high vulnerability. Among top 100 climate-vulnerable countries.
- Sea level rise: Colombo, Negombo, Galle, Jaffna coastal flooding risk.
- Monsoon variability: SW + NE patterns shifting; drought + flood swings.
- Tea industry: declining yields due to rising temperatures (optimal 15-27°C).
- Paddy: climate stress on Maha + Yala seasons.
- Coral bleaching: 2016, 2024 mass events.
- Cyclone intensification: Bay of Bengal storms more severe.
- Wet zone landslides + dry zone droughts both intensified.
- Health: dengue range expansion; heat stress.
SL Contribution + Commitments
- SL emissions: ~1 ton/capita — very low globally.
- Paris signatory — submitted NDCs.
- Updated NDC 2021: 14.5% emission reduction by 2030; 70% renewable electricity by 2030.
- Carbon neutral by 2050 target.
- National Adaptation Plan 2016-25.
- Mahaweli + Climate-Smart Irrigation programs.
Initiatives
- Soorya Bala Sangramaya 2016 — rooftop solar.
- Mannar Wind Farm — 100MW + expansion.
- Mangrove restoration — Negombo, Madu Ganga.
- Climate-resilient agriculture — drought-tolerant paddy varieties (BG, AT series).
- EV promotion — emerging policy.
- Hambantota wind + solar zones.
- Green Climate Fund (GCF) projects.
⭐ பரீட்சைக் குறிப்புகள் — மறக்காதே
- Weather (now/day) vs Climate (30yr avg) vs Climate Change (multi-decade shift).
- Natural greenhouse effect = essential (~+15°C vs -18°C without).
- Enhanced (human-caused) effect = problem. CO₂ 280→425+ ppm; global temp +1.1°C.
- Main GHGs: CO₂ (75%, fossil fuels), CH₄ methane (84× GWP), N₂O (273× GWP), F-gases.
- Emitters by sector: Energy 75% + Agri/Land 20% + Industry/Waste 5%.
- Per capita: Qatar 37 / USA 14 / China 7.5 / EU 6 / India 1.9 / SL 1 / Burundi 0.05.
- Effects: +1.1°C, Arctic ice loss, +25cm sea level, extreme weather, coral bleaching, ecosystems.
- UNFCCC 1992 Rio → Kyoto 1997 → Paris 2015 → COPs annual. IPCC 1988.
- Paris Agreement: 1.5°C target, NDCs, $100B/yr finance, net-zero 2050.
- Montreal Protocol 1987 — CFC ban; most successful environmental treaty (ozone recovering).
- Mitigation (reduce/remove GHG) vs Adaptation (cope with impacts).
- SL NDC 2021: 14.5% reduction; 70% RE by 2030; carbon neutral 2050.
- SL vulnerability: sea level, monsoons, tea decline, coral bleaching, dengue.
⚠ மாணவர்கள் செய்யும் பொதுத் தவறுகள்
- "Weather = Climate" — different. Weather=short; Climate=30yr avg; Climate Change=long-term shift.
- "Greenhouse effect bad always" — Natural is essential for life. Enhanced (extra) is problem.
- "CO₂ only GHG" — also methane (84× stronger short-term), N₂O, F-gases, water vapor.
- "Climate change = no winter" — warming average; weather extremes both ways possible.
- "Kyoto = Paris" — Kyoto binding developed only; Paris universal voluntary.
- "Sea level rise small" — 25 cm + accelerating; coastal infrastructure threatened.
- "SL not contributing" — very low emissions but Paris signatory + NDC targets.
- Mitigation vs Adaptation — different strategies; both needed.
✅ விரைவுச் சோதனை
முக்கியக் கருத்துக்களை உறுதிப்படுத்துங்கள். தவறான விடைகள் உங்கள் தவறுக் குறிப்பேட்டில் சேமிக்கப்படும்.
🖊 கட்டுரை வினாக்கள் (பகுதி II)
பரீட்சை வடிவில் கட்டமைப்பு வினாக்கள். முதலில் நீங்களே எழுதுங்கள்; பின்னர் மாதிரி விடையைத் திறந்து சரிபாருங்கள்.
1. \"Climate change\" — definition, greenhouse effect mechanism, main GHGs, anthropogenic causes — விளக்குக. (8 புள்ளி)
விடைத் திட்டம் — சேர்க்க வேண்டிய புள்ளிகள்:
- Weather (short) vs Climate (30yr avg) vs Climate Change (multi-decade)
- Natural greenhouse essential; enhanced is problem
- Main GHGs: CO₂ (75%), CH₄ (84x), N₂O (273x), F-gases
- Sectors: Energy 75% + Agri/Land 20% + Industry 5%
- CO₂ 280→425+ ppm; temp +1.1°C
- Per capita: USA 14, China 7.5, SL 1, Burundi 0.05
**Definitions:**
**Weather (வானிலை):** Atmospheric state at a specific time + place — temperature, rainfall, humidity, wind. Minutes-to-days timeframe. "Today's evening rain."
**Climate (காலநிலை):** The 30-year average of weather at a place. Decades+ timeframe. "Nuwara Eliya is cool."
**Climate Change (காலநிலை மாற்றம்):** Sustained shift in climate over decades+. Can be natural (Milankovitch cycles, volcanoes, solar variability — slow over millennia) or **anthropogenic** (human-caused, current rapid warming).
**Greenhouse Effect Mechanism:**
*Natural Greenhouse Effect (Essential):*
1. Sun emits short-wave radiation (UV + visible light) reaching Earth.
2. Earth absorbs and warms.
3. Earth re-emits energy as long-wave infrared radiation.
4. **Greenhouse gases (H₂O, CO₂, CH₄, N₂O)** in atmosphere absorb infrared and re-radiate downward — trapping heat.
5. Result: Earth's surface ~+15°C (warm enough for life).
Without natural greenhouse effect, Earth would average **-18°C** — frozen and lifeless. So greenhouse effect = essential.
*Enhanced (Anthropogenic) Greenhouse Effect (Problem):*
Humans dump extra GHG into atmosphere → enhanced heat trapping → **global warming + climate change**. Industrial Revolution (1850) started this dramatically. CO₂: 280 ppm → 425+ ppm (2024) — 50%+ increase. Global mean temperature: +1.1°C above pre-industrial.
**Main GHGs + GWP (Global Warming Potential over 100 yrs):**
| Gas | Sources | GWP | Lifetime |
|---|---|---|---|
| **CO₂** | Fossil fuels, deforestation, cement, transport | **1** (baseline) | 100-1000+ yrs |
| **CH₄** Methane | Livestock, rice paddies, landfills, gas leaks | **~84** | ~12 yrs |
| **N₂O** Nitrous oxide | Fertilizers, soil microbes, industry | **~273** | ~114 yrs |
| **F-gases** (HFC, PFC, SF₆) | Refrigeration, electronics | 1,000-23,000 | Variable |
| **H₂O** Water vapor | Natural; amplifies other warming | — | Days |
**CO₂ = 75% of anthropogenic forcing — primary culprit.** Methane = significant short-term impact (84× CO₂ in 100 yrs). F-gases = extreme GWP but small volumes.
**Anthropogenic Causes by Sector:**
**(1) Energy ~75% of emissions:**
- **Electricity + heat generation** — coal, gas, oil power plants. China + India + USA biggest emitters.
- **Transport ~20% global** — cars, trucks, aviation, shipping.
- **Industry** — steel + cement + chemicals + manufacturing.
- **Buildings** — heating, AC, lighting.
**(2) Agriculture + Land Use ~20%:**
- **Livestock (cattle)** — methane belching; alone ~14% of global GHG.
- **Rice paddies** — anaerobic methane.
- **Synthetic fertilizers** — N₂O from soil.
- **Deforestation** — Amazon, Congo, Indonesia. Releases stored carbon + reduces future sink.
**(3) Industry + Waste ~5%:**
- Cement production (CaCO₃ → CaO + CO₂).
- Steel + aluminium smelting.
- F-gases from refrigeration.
- Landfill methane.
**Cumulative Historical Emissions (1850-2023):**
- USA ~25% (industrial pioneer)
- EU ~17%
- China ~14% (recent surge but cumulative still less)
- Russia ~7%
- Africa ~3% (lowest historically)
**Per Capita Emissions (2024):**
- **Qatar 37** tons CO₂/person — highest (oil/gas economy)
- **USA 14**
- **Australia 16**
- **Russia 12**
- **China 7.5**
- **EU 6**
- **India 1.9**
- **Sri Lanka ~1** — very low
- **Burundi 0.05** — among lowest
**Equity Issue:** Top 10% richest emit 50% of emissions; bottom 50% emit 10%. Climate justice — historic emitters owe more responsibility.
IPCC AR6 (2021-22) conclusively attributes observed warming to human activities — "unequivocal."
**Weather (வானிலை):** Atmospheric state at a specific time + place — temperature, rainfall, humidity, wind. Minutes-to-days timeframe. "Today's evening rain."
**Climate (காலநிலை):** The 30-year average of weather at a place. Decades+ timeframe. "Nuwara Eliya is cool."
**Climate Change (காலநிலை மாற்றம்):** Sustained shift in climate over decades+. Can be natural (Milankovitch cycles, volcanoes, solar variability — slow over millennia) or **anthropogenic** (human-caused, current rapid warming).
**Greenhouse Effect Mechanism:**
*Natural Greenhouse Effect (Essential):*
1. Sun emits short-wave radiation (UV + visible light) reaching Earth.
2. Earth absorbs and warms.
3. Earth re-emits energy as long-wave infrared radiation.
4. **Greenhouse gases (H₂O, CO₂, CH₄, N₂O)** in atmosphere absorb infrared and re-radiate downward — trapping heat.
5. Result: Earth's surface ~+15°C (warm enough for life).
Without natural greenhouse effect, Earth would average **-18°C** — frozen and lifeless. So greenhouse effect = essential.
*Enhanced (Anthropogenic) Greenhouse Effect (Problem):*
Humans dump extra GHG into atmosphere → enhanced heat trapping → **global warming + climate change**. Industrial Revolution (1850) started this dramatically. CO₂: 280 ppm → 425+ ppm (2024) — 50%+ increase. Global mean temperature: +1.1°C above pre-industrial.
**Main GHGs + GWP (Global Warming Potential over 100 yrs):**
| Gas | Sources | GWP | Lifetime |
|---|---|---|---|
| **CO₂** | Fossil fuels, deforestation, cement, transport | **1** (baseline) | 100-1000+ yrs |
| **CH₄** Methane | Livestock, rice paddies, landfills, gas leaks | **~84** | ~12 yrs |
| **N₂O** Nitrous oxide | Fertilizers, soil microbes, industry | **~273** | ~114 yrs |
| **F-gases** (HFC, PFC, SF₆) | Refrigeration, electronics | 1,000-23,000 | Variable |
| **H₂O** Water vapor | Natural; amplifies other warming | — | Days |
**CO₂ = 75% of anthropogenic forcing — primary culprit.** Methane = significant short-term impact (84× CO₂ in 100 yrs). F-gases = extreme GWP but small volumes.
**Anthropogenic Causes by Sector:**
**(1) Energy ~75% of emissions:**
- **Electricity + heat generation** — coal, gas, oil power plants. China + India + USA biggest emitters.
- **Transport ~20% global** — cars, trucks, aviation, shipping.
- **Industry** — steel + cement + chemicals + manufacturing.
- **Buildings** — heating, AC, lighting.
**(2) Agriculture + Land Use ~20%:**
- **Livestock (cattle)** — methane belching; alone ~14% of global GHG.
- **Rice paddies** — anaerobic methane.
- **Synthetic fertilizers** — N₂O from soil.
- **Deforestation** — Amazon, Congo, Indonesia. Releases stored carbon + reduces future sink.
**(3) Industry + Waste ~5%:**
- Cement production (CaCO₃ → CaO + CO₂).
- Steel + aluminium smelting.
- F-gases from refrigeration.
- Landfill methane.
**Cumulative Historical Emissions (1850-2023):**
- USA ~25% (industrial pioneer)
- EU ~17%
- China ~14% (recent surge but cumulative still less)
- Russia ~7%
- Africa ~3% (lowest historically)
**Per Capita Emissions (2024):**
- **Qatar 37** tons CO₂/person — highest (oil/gas economy)
- **USA 14**
- **Australia 16**
- **Russia 12**
- **China 7.5**
- **EU 6**
- **India 1.9**
- **Sri Lanka ~1** — very low
- **Burundi 0.05** — among lowest
**Equity Issue:** Top 10% richest emit 50% of emissions; bottom 50% emit 10%. Climate justice — historic emitters owe more responsibility.
IPCC AR6 (2021-22) conclusively attributes observed warming to human activities — "unequivocal."
2. \"Climate change effects\" — temperature, cryosphere, sea level, extreme weather, ecological, human — விளக்குக. (8 புள்ளி)
விடைத் திட்டம் — சேர்க்க வேண்டிய புள்ளிகள்:
- +1.1°C global mean
- Arctic ice declining 13%/decade
- Sea level +25cm; projected 30-100cm
- Extreme heatwaves/cyclones/floods/droughts/fires
- Coral bleaching, species shifts, mass extinction
- Climate migration 100M+ by 2050
- SL: tea decline, coral, sea level, dengue
Climate change is no longer abstract — observable effects manifest across atmosphere, oceans, land, and ecosystems globally.
**1. Temperature:**
- **Global mean surface temperature +1.1°C** above pre-industrial (1850-1900 baseline) by 2024 — IPCC AR6.
- **Each of the last 10 years among hottest on record.**
- **2023 + 2024 = hottest years ever recorded** — record consecutively shattered.
- **Arctic warming 2-3× the global average** — "Arctic amplification."
- Heat records being broken constantly — Death Valley 56°C 2020; Lytton Canada 49.6°C 2021; Delhi 49°C 2024.
**2. Cryosphere (Ice & Snow):**
- **Arctic sea ice** declining ~13% per decade since satellite records 1979. Could be ice-free in summer by 2050 (some scenarios 2030s).
- **Greenland ice sheet** losing 280 billion tons/year.
- **Antarctica** ice losses accelerating, especially West Antarctica.
- **Mountain glaciers** retreating worldwide — Himalayas (Ganges/Indus sources threatened), Alps, Andes, Africa's last glaciers vanishing.
- **Permafrost thawing** — releases stored methane (positive feedback loop, dangerous tipping point).
- **Snowpack** declining — water resource concerns for billions.
**3. Sea Level Rise:**
- **+25 cm since 1900**; accelerating to ~4 mm/year recently.
- **Projected +30-100 cm by 2100** depending on emissions pathway.
- Threatens **coastal cities** — Mumbai, Jakarta (sinking + rising), Shanghai, Colombo, NYC, Miami, Bangkok.
- **Small island nations existential threat** — Maldives (max elevation 2m), Tuvalu, Marshall Islands. Could disappear.
- **Coastal erosion** worse during storm events.
- **Saltwater intrusion** into aquifers + estuaries.
**4. Extreme Weather (more intense + frequent):**
- **Heatwaves** — Europe 2003 (~70K dead), Russia 2010, India/Pakistan 2015 + 2022 + 2024.
- **Cyclones/Hurricanes** — Cat 4-5 proportion rising; rapid intensification more common.
- **Heavy rainfall** — atmosphere holds 7% more moisture per °C warming → more intense downpours.
- **Floods** — 2022 Pakistan (1/3 country submerged), 2023 Libya Derna dam burst (11K dead).
- **Droughts** — California, Horn of Africa, Cape Town 2018, European 2022.
- **Wildfires** — Australia 2019-20 "Black Summer" (18M ha, 3B animals), California Camp Fire 2018 (Paradise destroyed), Canada 2023 (18M ha).
**5. Ocean Changes:**
- **Ocean warming** — 90% of excess heat absorbed.
- **Acidification** — CO₂ + seawater = carbonic acid; pH dropping (0.1 since pre-industrial).
- **Coral bleaching** — Great Barrier Reef mass events 2016, 2017, 2020, 2024.
- **Ocean deoxygenation** — warmer water holds less O₂.
- **Marine heatwaves** — fishery collapse.
- **Algal blooms** — toxic, depleting oxygen.
**6. Ecological Impact:**
- **Species range shifts** — polar species disappearing (polar bears, narwhals); tropical species expanding.
- **Phenology disruption** — flowers blooming earlier; bird migration mismatch with insects.
- **Mass extinction acceleration** — IPBES estimates 1M+ species at risk.
- **Coral reef collapse** — could disappear 70-90% by 2050 with 1.5°C warming.
- **Forest mortality** — heat + drought + pest outbreaks (Western US pine beetles).
- **Insect collapse** — biodiversity crisis.
**7. Agricultural + Food Security:**
- **Crop yields stressed** — maize, wheat declining in tropics.
- **Coffee zones shifting** — 50%+ unsuitable by 2050.
- **Tea industry** affected — Kenya, Sri Lanka, India climate-stressed.
- **Fishery shifts** — fish migrating to cooler waters; tropical food security threatened.
- **Livestock heat stress** — productivity decline.
**8. Human Health Impact:**
- **Heat-related deaths rising** globally.
- **Vector-borne disease range expansion** — dengue, malaria, Zika spreading to new areas.
- **Air quality** worse with heat + wildfires + drought-driven dust.
- **Mental health** "eco-anxiety," climate trauma.
- **Water stress** affecting 2B+ people; conflicts.
**9. Climate Migration + Conflict:**
- **100M+ people projected to migrate** by 2050 due to climate (World Bank Groundswell).
- **Climate-conflict links** — Syria drought 2006-10 contributed to civil war; Darfur drought conflict; Lake Chad shrinkage + jihadi recruitment.
- **Coastal communities** displaced (Bangladesh, India, Vietnam).
- **Mountain communities** facing water + landslide crises.
**Sri Lanka Specific:**
- **Sea level rise** — Colombo, Negombo, Galle, Jaffna coastal infrastructure threatened. Hambantota Port vulnerable.
- **Monsoon variability** — both worse droughts AND worse floods. 2016-17 drought followed by 2017 flood demonstrates.
- **Tea industry decline** — rising temperatures stress optimal 15-27°C range; lower altitude tea hardest hit.
- **Paddy stress** — Maha + Yala seasons affected; rice yields can decline 5-15%.
- **Coral bleaching** 2016, 2024 mass events at Hikkaduwa, Pigeon Island, Bar Reef.
- **Cyclone intensification** — Bay of Bengal storms stronger.
- **Wet zone landslides + dry zone droughts** both intensified.
- **Dengue range expansion** — now in dry zone areas previously immune.
- **Heat stress** — Colombo summer extremes.
IPCC projections: at 1.5°C, severe but adaptable; at 2°C, dangerous; at 3-4°C, catastrophic and uninhabitable in some regions.
**1. Temperature:**
- **Global mean surface temperature +1.1°C** above pre-industrial (1850-1900 baseline) by 2024 — IPCC AR6.
- **Each of the last 10 years among hottest on record.**
- **2023 + 2024 = hottest years ever recorded** — record consecutively shattered.
- **Arctic warming 2-3× the global average** — "Arctic amplification."
- Heat records being broken constantly — Death Valley 56°C 2020; Lytton Canada 49.6°C 2021; Delhi 49°C 2024.
**2. Cryosphere (Ice & Snow):**
- **Arctic sea ice** declining ~13% per decade since satellite records 1979. Could be ice-free in summer by 2050 (some scenarios 2030s).
- **Greenland ice sheet** losing 280 billion tons/year.
- **Antarctica** ice losses accelerating, especially West Antarctica.
- **Mountain glaciers** retreating worldwide — Himalayas (Ganges/Indus sources threatened), Alps, Andes, Africa's last glaciers vanishing.
- **Permafrost thawing** — releases stored methane (positive feedback loop, dangerous tipping point).
- **Snowpack** declining — water resource concerns for billions.
**3. Sea Level Rise:**
- **+25 cm since 1900**; accelerating to ~4 mm/year recently.
- **Projected +30-100 cm by 2100** depending on emissions pathway.
- Threatens **coastal cities** — Mumbai, Jakarta (sinking + rising), Shanghai, Colombo, NYC, Miami, Bangkok.
- **Small island nations existential threat** — Maldives (max elevation 2m), Tuvalu, Marshall Islands. Could disappear.
- **Coastal erosion** worse during storm events.
- **Saltwater intrusion** into aquifers + estuaries.
**4. Extreme Weather (more intense + frequent):**
- **Heatwaves** — Europe 2003 (~70K dead), Russia 2010, India/Pakistan 2015 + 2022 + 2024.
- **Cyclones/Hurricanes** — Cat 4-5 proportion rising; rapid intensification more common.
- **Heavy rainfall** — atmosphere holds 7% more moisture per °C warming → more intense downpours.
- **Floods** — 2022 Pakistan (1/3 country submerged), 2023 Libya Derna dam burst (11K dead).
- **Droughts** — California, Horn of Africa, Cape Town 2018, European 2022.
- **Wildfires** — Australia 2019-20 "Black Summer" (18M ha, 3B animals), California Camp Fire 2018 (Paradise destroyed), Canada 2023 (18M ha).
**5. Ocean Changes:**
- **Ocean warming** — 90% of excess heat absorbed.
- **Acidification** — CO₂ + seawater = carbonic acid; pH dropping (0.1 since pre-industrial).
- **Coral bleaching** — Great Barrier Reef mass events 2016, 2017, 2020, 2024.
- **Ocean deoxygenation** — warmer water holds less O₂.
- **Marine heatwaves** — fishery collapse.
- **Algal blooms** — toxic, depleting oxygen.
**6. Ecological Impact:**
- **Species range shifts** — polar species disappearing (polar bears, narwhals); tropical species expanding.
- **Phenology disruption** — flowers blooming earlier; bird migration mismatch with insects.
- **Mass extinction acceleration** — IPBES estimates 1M+ species at risk.
- **Coral reef collapse** — could disappear 70-90% by 2050 with 1.5°C warming.
- **Forest mortality** — heat + drought + pest outbreaks (Western US pine beetles).
- **Insect collapse** — biodiversity crisis.
**7. Agricultural + Food Security:**
- **Crop yields stressed** — maize, wheat declining in tropics.
- **Coffee zones shifting** — 50%+ unsuitable by 2050.
- **Tea industry** affected — Kenya, Sri Lanka, India climate-stressed.
- **Fishery shifts** — fish migrating to cooler waters; tropical food security threatened.
- **Livestock heat stress** — productivity decline.
**8. Human Health Impact:**
- **Heat-related deaths rising** globally.
- **Vector-borne disease range expansion** — dengue, malaria, Zika spreading to new areas.
- **Air quality** worse with heat + wildfires + drought-driven dust.
- **Mental health** "eco-anxiety," climate trauma.
- **Water stress** affecting 2B+ people; conflicts.
**9. Climate Migration + Conflict:**
- **100M+ people projected to migrate** by 2050 due to climate (World Bank Groundswell).
- **Climate-conflict links** — Syria drought 2006-10 contributed to civil war; Darfur drought conflict; Lake Chad shrinkage + jihadi recruitment.
- **Coastal communities** displaced (Bangladesh, India, Vietnam).
- **Mountain communities** facing water + landslide crises.
**Sri Lanka Specific:**
- **Sea level rise** — Colombo, Negombo, Galle, Jaffna coastal infrastructure threatened. Hambantota Port vulnerable.
- **Monsoon variability** — both worse droughts AND worse floods. 2016-17 drought followed by 2017 flood demonstrates.
- **Tea industry decline** — rising temperatures stress optimal 15-27°C range; lower altitude tea hardest hit.
- **Paddy stress** — Maha + Yala seasons affected; rice yields can decline 5-15%.
- **Coral bleaching** 2016, 2024 mass events at Hikkaduwa, Pigeon Island, Bar Reef.
- **Cyclone intensification** — Bay of Bengal storms stronger.
- **Wet zone landslides + dry zone droughts** both intensified.
- **Dengue range expansion** — now in dry zone areas previously immune.
- **Heat stress** — Colombo summer extremes.
IPCC projections: at 1.5°C, severe but adaptable; at 2°C, dangerous; at 3-4°C, catastrophic and uninhabitable in some regions.
3. \"International climate response\" — UNFCCC, Kyoto Protocol, Paris Agreement, COPs, Sri Lanka commitments — விளக்குக. (8 புள்ளி)
விடைத் திட்டம் — சேர்க்க வேண்டிய புள்ளிகள்:
- UNFCCC 1992 Rio Earth Summit; IPCC 1988
- Kyoto Protocol 1997 binding developed-country targets only
- Paris Agreement 2015 (COP21) — universal; 1.5°C target; NDCs
- Climate finance $100B/yr; net-zero 2050
- Montreal Protocol 1987 ozone success
- COP key milestones
- Sri Lanka NDC 14.5% reduction; 70% RE by 2030; carbon neutral 2050
International climate response evolved over 35 years through multiple treaties + institutions, with mixed success.
**Foundation:**
- **IPCC (Intergovernmental Panel on Climate Change)** — established 1988 by WMO + UNEP. Provides scientific assessment. Six Assessment Reports (AR1-6) plus special reports. Nobel Peace Prize 2007.
- **UNFCCC (UN Framework Convention on Climate Change)** — 1992 Rio Earth Summit. ~196 parties. Foundational treaty defining cooperative action. "Common but differentiated responsibilities" principle.
- **COP (Conference of Parties)** — annual UNFCCC meeting since 1995. COP29 was Baku 2024.
**Kyoto Protocol (1997, COP3):**
- First binding emission targets.
- **Developed (Annex I) countries only** committed to specific reductions: ~5% below 1990 levels by 2008-12.
- Developing countries (China, India) not bound — recognized historical responsibility.
- Mechanisms: Clean Development Mechanism (CDM), Joint Implementation, Emissions Trading.
- **Limited success:** USA never ratified (Senate concerns); Canada withdrew 2011. Many countries missed targets. Major emitters not constrained.
- Doha Amendment 2012 extended to 2020.
**Paris Agreement (2015, COP21):**
Landmark universal agreement.
**Key features:**
1. **Universal participation** — all 196 parties commit, including USA, China, India.
2. **Temperature goal:** "Hold the increase in global average temperature **well below 2°C** above pre-industrial levels and pursue efforts to limit warming to **1.5°C**."
3. **NDCs (Nationally Determined Contributions)** — countries voluntarily set + update targets every 5 years. Progressive ratcheting up ambition.
4. **Transparency framework** — common reporting requirements.
5. **Climate finance:** Developed countries provide **$100 billion/year** to developing (mobilization). Largely unmet through 2020s.
6. **Net-zero by mid-century:** Most developed countries target 2050; China 2060; India 2070; ~140 countries pledged.
7. **Loss & Damage** — formal recognition of impacts beyond adaptation.
**Strengths + Weaknesses:** Universal participation a triumph. But voluntary NDCs lack enforcement. Current NDC commitments put world on ~2.5-2.8°C path — insufficient.
**USA history:** Trump withdrew 2017 (effective 2020); Biden rejoined 2021. Withdrawal possibility under Trump 2.0 (2025).
**Recent COPs:**
- **COP21 Paris 2015** — Paris Agreement.
- **COP22 Marrakech 2016** — implementation discussions.
- **COP26 Glasgow 2021** — coal "phase-down" language; Global Methane Pledge (150+ countries).
- **COP27 Sharm El-Sheikh 2022** — "Loss & Damage Fund" agreed; vulnerable countries get compensation funding (operationalized COP28).
- **COP28 Dubai 2023** — first explicit "transition away from fossil fuels" language in final text. Triple renewables + double energy efficiency by 2030.
- **COP29 Baku 2024** — "New Collective Quantified Goal" — $300 billion/year climate finance target by 2035 (developing country aspirations had been $1.3 trillion).
- **COP30 Belem 2025** — Amazon focus.
**Montreal Protocol (1987) — Ozone Layer:**
- Different treaty addressing CFC ozone depletion (not climate).
- **Most successful environmental treaty ever** — 100% ratification. CFCs phased out.
- **Ozone layer recovering** — projected full recovery by 2065.
- Many ozone-depleting substances are also greenhouse gases — co-benefit.
- **Kigali Amendment 2016** — phases down HFC refrigerants (potent GHGs).
**Other Climate Initiatives:**
- **G20 climate commitments** + tracking.
- **High Ambition Coalition** — vulnerable + ambitious countries pushing 1.5°C.
- **AOSIS (Alliance of Small Island States)** — vulnerable island advocates.
- **Race to Zero (UN)** — net-zero campaign.
- **GFANZ (Glasgow Financial Alliance for Net Zero)** — finance sector.
- **Just Energy Transition Partnerships (JETP)** — South Africa, Indonesia, Vietnam, Senegal deals.
- **EU Carbon Border Adjustment Mechanism (CBAM)** — tariffs on imports from countries without carbon pricing.
**Sri Lanka Commitments:**
**Updated NDC (2021):**
- **14.5% emission reduction by 2030** vs business-as-usual.
- **70% renewable electricity by 2030** (currently ~50%).
- **Carbon neutral by 2050** target.
- **Conditional + unconditional components** — more ambitious with international finance.
**Specific commitments:**
- Forest cover increase to 32% by 2030.
- 100% electric vehicles for government fleet.
- Reduce industrial emissions.
- Climate-smart agriculture.
- Coastal adaptation infrastructure.
**National Frameworks:**
- **National Adaptation Plan (NAP) 2016-25** — sector-wide adaptation strategy.
- **National Climate Change Policy 2012** + **Strategy 2016**.
- **Ministry of Environment** coordinates.
- **Sustainable Development Council**.
- **NDC Implementation Plan.**
**Implementation initiatives:**
- **Soorya Bala Sangramaya 2016** — rooftop solar PV scheme; net-metering; ~700 MW installed.
- **Mannar Wind Farm** — 100 MW + expansion to 250 MW.
- **Hambantota wind + solar zones.**
- **Mahaweli Hydropower** — existing renewable backbone.
- **Mangrove restoration** — Negombo Lagoon, Madu Ganga.
- **Drought-tolerant paddy varieties** — BG, AT series.
- **EV promotion** — emerging policy + import duty restructuring.
- **Tea sector adaptation** — high-elevation transition.
- **Coastal Conservation** — beach protection, mangrove forests.
**Climate Finance:**
- **Green Climate Fund (GCF)** — SL has received millions for adaptation projects.
- **Adaptation Fund** projects.
- **Bilateral aid** (Japan, EU, USA, Australia, Germany).
- **NAMA** (Nationally Appropriate Mitigation Actions) facility.
**Challenges:**
1. **Limited domestic financing** post-2022 crisis.
2. **Coal dependence** Norochcholai 35% electricity; politically difficult to phase out.
3. **Transport** car-heavy + no metro.
4. **Land-use conflicts** for wind/solar farms.
5. **Capacity constraints** at sub-national level.
6. **Public awareness** moderate.
7. **Climate justice argument** — SL emissions 1 ton/capita while suffering disproportionate climate impacts.
**SL's Climate Diplomacy:**
- Member of **G77 + China** developing country bloc.
- Member of **Climate Vulnerable Forum (CVF)**.
- Champion of **loss & damage** advocacy.
- Active in **Indian Ocean Rim Association (IORA)** climate work.
- Hosted **South Asia regional dialogues**.
**Foundation:**
- **IPCC (Intergovernmental Panel on Climate Change)** — established 1988 by WMO + UNEP. Provides scientific assessment. Six Assessment Reports (AR1-6) plus special reports. Nobel Peace Prize 2007.
- **UNFCCC (UN Framework Convention on Climate Change)** — 1992 Rio Earth Summit. ~196 parties. Foundational treaty defining cooperative action. "Common but differentiated responsibilities" principle.
- **COP (Conference of Parties)** — annual UNFCCC meeting since 1995. COP29 was Baku 2024.
**Kyoto Protocol (1997, COP3):**
- First binding emission targets.
- **Developed (Annex I) countries only** committed to specific reductions: ~5% below 1990 levels by 2008-12.
- Developing countries (China, India) not bound — recognized historical responsibility.
- Mechanisms: Clean Development Mechanism (CDM), Joint Implementation, Emissions Trading.
- **Limited success:** USA never ratified (Senate concerns); Canada withdrew 2011. Many countries missed targets. Major emitters not constrained.
- Doha Amendment 2012 extended to 2020.
**Paris Agreement (2015, COP21):**
Landmark universal agreement.
**Key features:**
1. **Universal participation** — all 196 parties commit, including USA, China, India.
2. **Temperature goal:** "Hold the increase in global average temperature **well below 2°C** above pre-industrial levels and pursue efforts to limit warming to **1.5°C**."
3. **NDCs (Nationally Determined Contributions)** — countries voluntarily set + update targets every 5 years. Progressive ratcheting up ambition.
4. **Transparency framework** — common reporting requirements.
5. **Climate finance:** Developed countries provide **$100 billion/year** to developing (mobilization). Largely unmet through 2020s.
6. **Net-zero by mid-century:** Most developed countries target 2050; China 2060; India 2070; ~140 countries pledged.
7. **Loss & Damage** — formal recognition of impacts beyond adaptation.
**Strengths + Weaknesses:** Universal participation a triumph. But voluntary NDCs lack enforcement. Current NDC commitments put world on ~2.5-2.8°C path — insufficient.
**USA history:** Trump withdrew 2017 (effective 2020); Biden rejoined 2021. Withdrawal possibility under Trump 2.0 (2025).
**Recent COPs:**
- **COP21 Paris 2015** — Paris Agreement.
- **COP22 Marrakech 2016** — implementation discussions.
- **COP26 Glasgow 2021** — coal "phase-down" language; Global Methane Pledge (150+ countries).
- **COP27 Sharm El-Sheikh 2022** — "Loss & Damage Fund" agreed; vulnerable countries get compensation funding (operationalized COP28).
- **COP28 Dubai 2023** — first explicit "transition away from fossil fuels" language in final text. Triple renewables + double energy efficiency by 2030.
- **COP29 Baku 2024** — "New Collective Quantified Goal" — $300 billion/year climate finance target by 2035 (developing country aspirations had been $1.3 trillion).
- **COP30 Belem 2025** — Amazon focus.
**Montreal Protocol (1987) — Ozone Layer:**
- Different treaty addressing CFC ozone depletion (not climate).
- **Most successful environmental treaty ever** — 100% ratification. CFCs phased out.
- **Ozone layer recovering** — projected full recovery by 2065.
- Many ozone-depleting substances are also greenhouse gases — co-benefit.
- **Kigali Amendment 2016** — phases down HFC refrigerants (potent GHGs).
**Other Climate Initiatives:**
- **G20 climate commitments** + tracking.
- **High Ambition Coalition** — vulnerable + ambitious countries pushing 1.5°C.
- **AOSIS (Alliance of Small Island States)** — vulnerable island advocates.
- **Race to Zero (UN)** — net-zero campaign.
- **GFANZ (Glasgow Financial Alliance for Net Zero)** — finance sector.
- **Just Energy Transition Partnerships (JETP)** — South Africa, Indonesia, Vietnam, Senegal deals.
- **EU Carbon Border Adjustment Mechanism (CBAM)** — tariffs on imports from countries without carbon pricing.
**Sri Lanka Commitments:**
**Updated NDC (2021):**
- **14.5% emission reduction by 2030** vs business-as-usual.
- **70% renewable electricity by 2030** (currently ~50%).
- **Carbon neutral by 2050** target.
- **Conditional + unconditional components** — more ambitious with international finance.
**Specific commitments:**
- Forest cover increase to 32% by 2030.
- 100% electric vehicles for government fleet.
- Reduce industrial emissions.
- Climate-smart agriculture.
- Coastal adaptation infrastructure.
**National Frameworks:**
- **National Adaptation Plan (NAP) 2016-25** — sector-wide adaptation strategy.
- **National Climate Change Policy 2012** + **Strategy 2016**.
- **Ministry of Environment** coordinates.
- **Sustainable Development Council**.
- **NDC Implementation Plan.**
**Implementation initiatives:**
- **Soorya Bala Sangramaya 2016** — rooftop solar PV scheme; net-metering; ~700 MW installed.
- **Mannar Wind Farm** — 100 MW + expansion to 250 MW.
- **Hambantota wind + solar zones.**
- **Mahaweli Hydropower** — existing renewable backbone.
- **Mangrove restoration** — Negombo Lagoon, Madu Ganga.
- **Drought-tolerant paddy varieties** — BG, AT series.
- **EV promotion** — emerging policy + import duty restructuring.
- **Tea sector adaptation** — high-elevation transition.
- **Coastal Conservation** — beach protection, mangrove forests.
**Climate Finance:**
- **Green Climate Fund (GCF)** — SL has received millions for adaptation projects.
- **Adaptation Fund** projects.
- **Bilateral aid** (Japan, EU, USA, Australia, Germany).
- **NAMA** (Nationally Appropriate Mitigation Actions) facility.
**Challenges:**
1. **Limited domestic financing** post-2022 crisis.
2. **Coal dependence** Norochcholai 35% electricity; politically difficult to phase out.
3. **Transport** car-heavy + no metro.
4. **Land-use conflicts** for wind/solar farms.
5. **Capacity constraints** at sub-national level.
6. **Public awareness** moderate.
7. **Climate justice argument** — SL emissions 1 ton/capita while suffering disproportionate climate impacts.
**SL's Climate Diplomacy:**
- Member of **G77 + China** developing country bloc.
- Member of **Climate Vulnerable Forum (CVF)**.
- Champion of **loss & damage** advocacy.
- Active in **Indian Ocean Rim Association (IORA)** climate work.
- Hosted **South Asia regional dialogues**.
🔥 மீட்டல் மையம்
பரீட்சைக்கு முன் இறுதி ஒரு நிமிடம் — மறக்கக்கூடாதவை மட்டும்.
- <b>Weather (short)</b> vs <b>Climate (30yr avg)</b> vs <b>Climate Change (multi-decade shift)</b>.
- <b>Natural greenhouse effect essential:</b> Earth +15°C vs -18°C without it.
- <b>Enhanced (human) effect = problem.</b> CO₂ 280→425+ ppm; global temp +1.1°C above pre-industrial.
- <b>Main GHGs:</b> CO₂ (75% emissions), CH₄ methane (84× GWP, 12 yr lifetime), N₂O (273× GWP), F-gases (1000-23000×).
- <b>Emissions by sector:</b> Energy 75% + Agriculture/Land 20% + Industry/Waste 5%.
- <b>Per capita CO₂:</b> Qatar 37, USA 14, China 7.5, EU 6, India 1.9, SL 1, Burundi 0.05.
- <b>Observed effects:</b> +1.1°C, Arctic ice loss 13%/decade, sea level +25cm, more extreme weather, coral bleaching, ecosystem stress.
- <b>UNFCCC 1992 Rio</b> + IPCC 1988 + COP annual.
- <b>Kyoto Protocol 1997:</b> binding developed-country targets only.
- <b>Paris Agreement 2015 (COP21):</b> Universal; 1.5°C target; NDCs every 5yr; $100B/yr finance; net-zero 2050.
- <b>Montreal Protocol 1987:</b> CFC ban — most successful environmental treaty.
- <b>SL NDC 2021:</b> 14.5% reduction by 2030; 70% RE by 2030; carbon neutral 2050.
- <b>Mitigation</b> (reduce GHG) vs <b>Adaptation</b> (cope with impacts).
அலகின் முதுகெலும்பு — கருத்துக்களும் தொடர்புகளும்.
- <b>Greenhouse Effect mechanism:</b> Sun emits shortwave (UV+visible) reaching Earth → Earth re-emits as infrared longwave → GHGs absorb + re-radiate downward → atmosphere warm.
- <b>GHGs detailed:</b> CO₂ from fossil fuels + deforestation + cement (75%, lifetime 100-1000yrs). CH₄ methane from cattle + rice + landfills + gas leaks (84× GWP, 12yr). N₂O from fertilizers + soil + industry (273× GWP, 114yr). F-gases (HFC/PFC/SF₆) from refrigeration + electronics (1000-23000× GWP).
- <b>Energy sector breakdown:</b> Electricity+heat generation (coal/gas/oil); Transport (cars/aviation/shipping 20%); Industry (steel/cement/chemicals); Buildings (heating/AC).
- <b>Agriculture sector:</b> Livestock alone 14% global GHG. Rice paddies anaerobic methane. Fertilizers N₂O. Deforestation (Amazon/Congo/Indonesia) releases stored carbon.
- <b>Cumulative emitters (1850-2023):</b> USA 25% (historical leader), EU 17%, China 14%, Russia 7%, Africa 3% (lowest historically).
- <b>Cryosphere effects:</b> Arctic sea ice -13%/decade; could vanish summer 2050. Greenland 280 billion tons/yr loss. Antarctica accelerating. Mountain glaciers retreating worldwide. Permafrost thawing = methane release positive feedback.
- <b>Sea level:</b> +25cm since 1900; +30-100cm projected by 2100. Coastal cities (Mumbai, Jakarta, Shanghai, Colombo, NYC, Miami) threatened. Small islands (Maldives 2m max, Tuvalu, Marshall) existential.
- <b>Extreme weather:</b> Heatwaves (Europe 2003 70K dead, India 2024 49°C); cyclones (Cat 4-5 fraction rising; rapid intensification); rainfall +7% per °C; floods (2022 Pakistan 1/3 submerged, 2023 Libya Derna 11K); droughts (Cape Town 2018, California, Horn of Africa); wildfires (Australia 2019-20 18M ha 3B animals, California, Canada 2023).
- <b>Ocean impacts:</b> 90% excess heat absorbed; acidification pH -0.1; coral bleaching mass events (2016, 2017, 2020, 2024); deoxygenation; marine heatwaves.
- <b>Ecological:</b> Species range shifts (polar disappearing, tropical expanding); phenology disruption (flowers earlier, bird migration mismatch); mass extinction acceleration; coral 70-90% loss at 1.5°C; insect collapse.
- <b>Human impacts:</b> Climate migration 100M+ by 2050 (World Bank Groundswell); dengue/malaria range expansion; heat-related deaths; water stress 2B+; conflicts (Syria drought, Darfur, Sahel).
- <b>Treaty chronology:</b> 1987 Montreal (CFC), 1988 IPCC, 1992 UNFCCC (Rio), 1997 Kyoto (developed binding), 2015 Paris (universal voluntary). COP26 Glasgow 2021 coal phase-down. COP27 Sharm 2022 Loss & Damage fund. COP28 Dubai 2023 first \"transition away from fossil fuels.\" COP29 Baku 2024 $300B/yr finance.
- <b>Paris mechanisms:</b> NDC every 5 years progressive; transparency framework; $100B/yr finance (largely unmet); ~140 countries pledged net-zero; current trajectory ~2.5-2.8°C (insufficient).
- <b>SL specific impacts:</b> Sea level (Colombo/Galle/Jaffna); monsoon variability (2016-17 drought then 2017 flood); tea industry decline (optimal 15-27°C stressed); paddy yield decline 5-15%; coral bleaching Hikkaduwa/Pigeon Island/Bar Reef; cyclone intensification Bay of Bengal; landslides + droughts both intensifying; dengue range expansion.
- <b>SL initiatives:</b> Soorya Bala Sangramaya rooftop solar 700MW; Mannar wind 100MW+expansion; mangrove restoration; drought-tolerant paddy BG/AT; EV policy emerging; Hambantota wind+solar zones; GCF projects.
பரீட்சைக்கு முந்தின இரவு முழு அலகையும் ஓட்டிப் பார்.
- <b>Critical Numbers:</b> +1.1°C global warming. CO₂ 280→425+ ppm. Sea level +25cm. Methane GWP 84×. SL emissions 1 ton/capita.
- <b>Key Years:</b> 1987 Montreal · 1988 IPCC · 1992 UNFCCC Rio · 1997 Kyoto · 2015 Paris (COP21).
- <b>Recent COPs:</b> COP26 Glasgow 2021 (coal). COP27 Sharm 2022 (Loss & Damage). COP28 Dubai 2023 (fossil fuel transition). COP29 Baku 2024 ($300B finance).
- <b>Paris targets:</b> 1.5°C / 2°C. NDCs every 5 yrs. $100B/yr finance. Net-zero 2050 (developed) / 2060 China / 2070 India.
- <b>SL NDC:</b> 14.5% reduction by 2030; 70% RE by 2030; carbon neutral 2050.
- <b>எளிதில் தவறும்:</b> (1) Weather ≠ Climate ≠ Climate Change. (2) Natural greenhouse essential; enhanced is problem. (3) CO₂ 75% but methane 84× stronger short-term. (4) Kyoto = developed-only binding; Paris = universal voluntary. (5) Montreal Protocol = ozone (separate, very successful); UNFCCC/Paris = climate. (6) Mitigation (reduce GHG) ≠ Adaptation (cope with impacts). (7) Sea level rise = 25 cm + accelerating (not small).
- <b>கட்டுரைக்குத் தயார்:</b> (1) Climate change definition + greenhouse mechanism + GHGs + causes. (2) Observed effects across temp/ice/sea/weather/ecology/humans. (3) International treaties + Paris + COPs + SL commitments.
- <b>Mitigation strategies:</b> Renewable energy, EVs, energy efficiency, carbon pricing, reforestation, sustainable agriculture, methane reduction, CCS, green hydrogen.
- <b>Adaptation strategies:</b> Coastal protection (sea walls + mangroves), climate-resilient crops, water management, disaster preparedness, infrastructure adjustment, health systems, insurance.
- <b>Climate justice:</b> Top 10% richest emit 50%; bottom 50% emit 10%. Historic emitters (USA, EU) bear more responsibility. SL/Africa/small islands suffer most despite minimal contributions.