Climate change & agreements

Answer: (c) 1 and 3 only

The 1978 Alma-Ata Declaration made primary health care the route to 'Health for All', and the Talanoa Dialogue was the 2018 UN climate process to take stock of Paris Agreement ambition. Biological weapons are banned by the Biological Weapons Convention, not a 'Hague Convention', and the Under2 Coalition is a climate pact of state, regional and city governments, not a child-rights body.

• ✓ 1. The Alma-Ata Declaration came out of the 1978 international conference on primary health care and treats health as a fundamental human right.
• ✗ 2. Biological weapons are prohibited by the Biological Weapons Convention, opened for signature in 1972 and negotiated in Geneva; chemical weapons are covered by the separate Chemical Weapons Convention. Neither is known as the Hague Convention.
• ✓ 3. The Talanoa Dialogue, launched under Fiji's COP23 presidency, invited countries and other stakeholders to ask 'Where are we? Where do we want to go? How do we get there?' on climate action under the Paris Agreement.
• ✗ 4. The Under2 Coalition is a group of state, regional and city governments that pledged to cut greenhouse gas emissions to limit warming; it has nothing to do with child rights.

Remember · Alma-Ata (1978): primary health care, Health for All. Talanoa Dialogue (COP23, Fiji): climate stocktake. Under2 Coalition: subnational governments' climate pact (2015). BWC 1972 bans biological weapons.

Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (a) 1, 2 and 3 only

Copper slag, cold mix and geotextiles are the green options for rural roads: they reuse industrial waste, save the fuel needed to heat bitumen, or cut the stone and soil needed. Hot mix asphalt and Portland cement are the conventional, energy-hungry materials.

• ✓ 1. Iron, steel and copper slag are on the list of proven technologies with Indian Roads Congress specifications (IRC SP:121-2018) that the rural roads agency (NRIDA) promotes; using this waste reduces demand for quarried aggregate.
• ✓ 2. Cold mix does not require heating the bitumen, which saves fuel and reduces pollution, and PMGSY lists it as a green technology.
• ✓ 3. Geotextiles, such as coir, strengthen the sub-grade soil and protect slopes, and the Rural Development Ministry lists coir geo-textiles among the new technologies under PMGSY.
• ✗ 4. Hot mix needs bitumen and aggregate to be heated, which is exactly what cold mix avoids, so it is the conventional, higher-fuel method.
• ✗ 5. Portland cement is the conventional binder; PMGSY's green list is about waste materials, cold mix, waste plastic and geosynthetics, not adding Portland cement.

Remember · Under PMGSY, green rural-road technologies include cold mix, waste plastic, industrial slags and geotextiles, which save fuel and natural aggregate.

Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) 1, 2 and 3

Why not the tempting option · UPSC's key is (d). Statement 3 says carbon sequestration 'is possible', which is the standard claim for no-till with residue retention — FAO's own account is that such systems accumulate more carbon in the soil and turn it into a net sink; the IPCC's caution that the evidence for net sequestration from no-till alone is not compelling qualifies the size of the gain, not the possibility. Statements 1 and 2 describe zero-till wheat sown through paddy stubble and no-till direct-seeded rice, both established practices. In the exam, read 'is possible' as a soft claim: one documented mechanism is enough.

Zero tillage means sowing the next crop directly into undisturbed soil without ploughing. All three are its advantages: wheat can be sown straight through paddy stubble without burning it, paddy can be direct-seeded without raising a nursery, and the undisturbed, residue-covered soil accumulates organic carbon.

• ✓ 1. Zero-till drills such as the Happy Seeder sow wheat straight through paddy stubble, so the residue need not be burnt; the Government promotes them for in-situ crop residue management in Punjab, Haryana, Uttar Pradesh and Delhi.
• ✓ 2. Direct seeding of rice into unpuddled, untilled soil skips the nursery and transplanting; trials in the Indo-Gangetic Plains found yields equal to puddled transplanting with 35–40 per cent less irrigation water.
• ✓ 3. Leaving the soil unploughed with residue on the surface slows the breakdown of organic matter; FAO notes that systems based on high residue addition and no tillage accumulate more carbon in the soil than plough-based tillage, turning the soil into a net carbon sink. It also cuts erosion and nutrient loss.

Remember · Zero tillage means sowing without ploughing: it lets farmers skip stubble burning and the rice nursery, cuts soil erosion, and builds up carbon in the soil.

Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink · Report an error

Answer: (a) long-term damage done by a tonne of CO2 emissions in a given year.

The Social Cost of Carbon is the money value of the long-term damage caused by one extra tonne of carbon dioxide emitted in a given year. Governments use it to weigh the benefits of cutting emissions against the costs of a policy.

• ✓ (a) This is the standard definition: a measure, in money terms, of the long-term damage done by a tonne of CO2 emitted in a given year; the same figure equals the damage avoided by cutting that tonne.
• ✗ (b) This describes a country's fossil-fuel demand, which is not a monetary damage measure.
• ✗ (c) The cost of adaptation by a climate refugee is not what the term measures; it values damage from emissions.
• ✗ (d) An individual's contribution is a personal carbon footprint, not the Social Cost of Carbon.

Remember · Social Cost of Carbon = money value of the long-term damage from one extra tonne of CO2 emitted in a year; equally, the benefit of avoiding it.

Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error