In which financial year did India issue its first sovereign green bonds?

The correct answer is C, one tonne of carbon dioxide equivalent. The tonne is the standard trading unit in every carbon market, compliance or voluntary, and it is written as 1 tCO2e. The word equivalent matters: gases other than carbon dioxide are converted into carbon dioxide terms using their global warming potential, so a much smaller quantity of methane or nitrous oxide can earn one credit. A is wrong because a kilogram is far too small to be a market unit; no registry issues credits in kilograms. B is wrong for the same reason, and a hundred kilograms is simply a tenth of the real unit, a figure offered to catch a candidate who half-remembers the tonne. D is wrong because a thousand tonnes is the scale of a whole small project's annual saving, not of a single credit; a project of that size would be issued a thousand separate credits, which is exactly how buyers are able to purchase them in small lots.

The correct answer is B, the Kyoto Protocol. Adopted in 1997 at COP3 in Japan and in force from 2005, it set binding emission targets for developed countries and gave them three flexible mechanisms to meet them; the Clean Development Mechanism, under Article 12, let a developed country fund an emission-reduction project in a developing country and claim the saving as Certified Emission Reductions. A is wrong because the Montreal Protocol of 1987 deals with ozone-depleting substances such as chlorofluorocarbons and has no emissions-trading machinery. C is wrong because the Cartagena Protocol, under the Convention on Biological Diversity, governs the transboundary movement of living modified organisms. D is wrong because the Nagoya Protocol, also under that Convention, covers access to genetic resources and the fair sharing of benefits from their use. Only the Kyoto Protocol belongs to the climate treaty family that creates carbon credits.

The correct answer is C, Certified Emission Reductions, abbreviated CER, each equal to one tonne of carbon dioxide equivalent and issued only after an accredited third party verifies the saving. India hosted a very large number of such projects and was among the world's biggest sellers of CERs. A is wrong because Emission Reduction Units arise from Joint Implementation, where one developed country funds a project in another developed country, not in a developing one. B is wrong because Assigned Amount Units are the emission allowances handed to developed countries themselves under Article 17, traded directly between governments rather than earned by a project. D is wrong because Renewable Energy Certificates are an Indian domestic instrument that lets an obliged buyer meet its renewable purchase obligation without owning a generating plant; they measure electricity from renewable sources, not avoided greenhouse gas, and have no standing under the Kyoto Protocol.

The correct answer is B, Article 6. It holds all the market machinery of the Paris Agreement: Article 6.2 lets two countries cooperate bilaterally and transfer Internationally Transferred Mitigation Outcomes with a corresponding adjustment so the same tonne is not counted twice, Article 6.4 establishes a centralised crediting mechanism supervised by a United Nations body as the successor to the Clean Development Mechanism, and Article 6.8 covers non-market approaches such as finance and technology transfer. A is wrong because Article 2 states the purpose of the agreement, including holding the temperature rise well below two degrees Celsius. C is wrong because Article 9 deals with climate finance from developed to developing countries. D is wrong because Article 14 provides for the global stocktake, the periodic review of collective progress. Note the coincidence candidates stumble on: Article 6 of the Kyoto Protocol is Joint Implementation, a different thing.

The correct answer is C, COP26 in Glasgow, held in 2021, where India placed a five-part pledge known as the Panchamrit before the conference: 500 GW of non-fossil energy capacity by 2030, half its energy requirement from renewables by 2030, a cut of one billion tonnes in projected emissions by 2030, a 45 per cent fall in the emission intensity of its gross domestic product by 2030 over the 2005 level, and net zero by 2070. A is wrong because COP21 in 2015 produced the Paris Agreement itself, years before any Indian net zero date was named. B is wrong because COP24 in Poland in 2018 is remembered for the Paris rulebook on transparency and accounting. D is wrong because COP28 in 2023 is associated with the first global stocktake, the operationalisation of the Loss and Damage Fund and the call to transition away from fossil fuels, not with India's net zero announcement.