Climate change Practice Questions

Carbon dioxide (CO2) from fossil fuel burning accounts for about 75% of greenhouse gas warming.

Joseph Fourier described it in 1824; John Tyndall measured gases in 1859; Svante Arrhenius quantified CO2 warming in 1896.

Agriculture (livestock, rice), fossil fuels, and waste are top sources; livestock enteric fermentation is largest single source.

Well below 2°C above pre-industrial, pursuing efforts to limit to 1.5°C.

Adopted at COP21 in Paris in December 2015, entered into force 2016.

Intergovernmental Panel on Climate Change, established by UNEP and WMO in 1988.

Around 420-424 ppm at Mauna Loa, up from 280 ppm pre-industrial.

Energy (electricity and heat) plus transport from fossil fuels is largest, about 73% of emissions.

IPCC AR6: methane GWP100 ≈ 27-30 times CO2 (previously 25-28).

Montreal Protocol (1987) successfully phased out CFCs, also climate benefit.

Adopted 1997, entered into force 2005, first commitment period 2008-2012.

Balancing anthropogenic emissions with removals, so net addition to atmosphere is zero.

Prime Minister announced net-zero by 2070, with 500 GW non-fossil by 2030.

Thermal expansion of seawater and melting of glaciers/ice sheets.

Oceans absorb ~25% of CO2, forming carbonic acid, lowering pH.

Anaerobic decomposition in flooded paddies produces methane.

2023 and 2024 surpassed previous records; 2024 was hottest at ~1.48°C above pre-industrial.

Proposed geological epoch dominated by human impact on climate and ecosystems.

Reflectivity of Earth’s surface; melting ice reduces albedo, causing more warming (positive feedback).

United States has emitted most cumulative CO2 since 1750, followed by EU and China.

China surpassed US around 2006 and remains largest annual emitter.

Conference of the Parties to UNFCCC, held annually since 1995.

Glasgow, UK in 2021.

Dubai, UAE in 2023, where global stocktake and loss and damage fund operationalized.

Support for vulnerable countries suffering unavoidable climate impacts.

National Solar Mission, part of 8 missions under National Action Plan on Climate Change (2008).

India’s National Action Plan on Climate Change launched in 2008.

Total greenhouse gases emitted directly/indirectly by activity, measured in CO2-equivalent.

Methane GWP20 ≈ 81-83, much higher short-term than CO2.

Thawing permafrost releases CO2 and methane, amplifying warming.

IPCC AR6: about 250-300 GtCO2 from 2023 for 50% chance of staying below 1.5°C.

Agriculture, especially synthetic fertilizers and manure.

Threshold where small change triggers irreversible large-scale shift, e.g., Greenland ice sheet collapse.

Deforestation + warming could shift to savanna, releasing carbon.

Carbon stored in coastal ecosystems: mangroves, seagrasses, salt marshes.

India ~2 tonnes per person vs global ~4.8 tonnes (2023), much lower.

West Bengal (Sundarbans), Gujarat, Tamil Nadu, Kerala coasts highly vulnerable.

Continuous record of atmospheric CO2 at Mauna Loa since 1958 by Charles Keeling.

Solar leads, surpassing wind, with over 80 GW installed.

Adjusting systems to reduce vulnerability to actual/expected climate impacts.

Actions to reduce emissions or enhance sinks to limit warming.

Tropical cyclones gain more energy from warmer sea surface temperatures.

Marine heatwaves from warming oceans cause corals to expel zooxanthellae.

Rio Earth Summit 1992.

Nationally Determined Contributions under Paris Agreement.

45% reduction from 2005 levels (updated 2022).

Launched at COP26 to cut methane 30% by 2030 from 2020 levels.

Capture and long-term storage of CO2 in forests, soils, oceans, or geological formations.

National Mission for Sustainable Agriculture (NMSA) under NAPCC.

Cities are warmer than rural areas due to concrete, less vegetation, waste heat.