Physical & Regional Geography

Statement I is correct: Without the atmosphere to trap heat, the Earth’s surface temperature would drop to well below freezing, making it too cold to support life as we know it.
In statement 1 though it's an extreme statement but from UPSC CSE point of view it's generally considered true. Statement II is correct: The atmosphere absorbs and retains heat (a natural greenhouse effect), which helps maintain the Earth’s average temperature within a habitable range. Statement III is correct: Gases such as carbon dioxide, methane, and water vapor are particularly effective at absorbing and trapping infrared radiation, helping to warm the planet.

✅ Statement I: Correct
In January, isotherms bend equatorward over land (which cools faster) and poleward over oceans (which retain heat). ✅ Statement II: Correct
Oceans stay warmer than land in January because water has a higher specific heat. ✅ Relationship:
Statement II explains why the isotherms behave as described in Statement I. Correct Answer: Both statements are correct, and Statement II explains Statement I.

✅ Statement I: Correct
Subtropical and temperate regions have more dust due to dry conditions, sparse vegetation, and strong winds. ❌ Statement II: Incorrect
Subtropical and temperate regions have more dry winds, not less, which help lift dust. Correct Answer: Only Statement I is correct.

Earth’s rotation and axis can shift due to changes in how mass is distributed across the planet, such as melting polar ice. ✅Statement I is correct: * Studies show that Earth’s rotation and axis are shifting slightly due to internal mass redistribution. ✅ Statement II is correct: * But it doesn’t explain the shift — solar flares affect only the upper atmosphere, not Earth’s rotation. ✅ Statement III is correct: * It explains the shift — melting polar ice moves water toward the equator, altering Earth’s mass distribution and spin.

Congo Basin Peatlands: The Congo Basin in Central Africa is home to the world's largest tropical peatland complex. This vast peatland stores an immense amount of carbon, estimated to be equivalent to about three years of global fossil fuel emissions.  Importance of Peatlands: Peatlands are a critical carbon sink. They store more carbon than all the world's forests combined. When peatlands are drained or degraded, this stored carbon is released into the atmosphere, contributing to climate change. The Republic of Congo, the Democratic Republic of Cong and Indonesia are parties to the Brazzaville Declaration, aimed at protecting the Cuvette Centrale region in the Congo Basin, the world’s largest tropical peatlands, from unregulated land use and preventing its drainage and degradation.  _Other Options:_  * Amazon Basin: While the Amazon is known for its vast rainforests, it is not the primary location of the world's largest tropical peatland. * Kikori Basin: The Kikori Basin is located in Papua New Guinea and contains significant peatlands, but not the largest tropical peatland complex. * Rio de la Plata Basin: This basin in South America is primarily known for its grasslands and is not associated with major peatland areas.

Statement 1 is incorrect. Insolation reaches the earth's surface in short waves and heat is radiated from the earth in long waves, Hence energy leaving the earth's surface i.e. terrestrial radiation heats up the atmosphere more than the incoming solar radiation i.e. insolation. Statement 2 is correct. Greenhouse gases in the atmosphere (such as water vapour and carbon dioxide) absorb most of the Earth's emitted longwave infrared radiation, which heats the lower atmosphere.

* Statement 1: Correct - Water vapour is indeed a gas, and its concentration generally decreases with altitude. This is because the air gets colder as we go higher, and colder air has a lower capacity to hold moisture. * Statement 2: Incorrect - The percentage of water vapour in the atmosphere is highest near the equator and decreases as we move towards the poles. This is because the tropics receive the maximum solar radiation, leading to higher temperatures and more evaporation, which in turn increases the amount of water vapour in the air.

Statement 1 (Equator) is incorrect:
The Equator experiences exactly 12 hours of daylight throughout the year, as it lies midway between the poles and the sun’s rays fall almost equally throughout the year. Statement 2 (Tropic of Cancer) is correct:
On June 21 (Summer Solstice), the Northern Hemisphere is tilted toward the Sun, and the Tropic of Cancer (23.5° N) receives the direct rays of the Sun.
Hence, regions along this latitude experience more than 12 hours of daylight. Statement 3 (Tropic of Capricorn) is incorrect:
The Tropic of Capricorn (23.5° S) lies in the Southern Hemisphere, which is tilted away from the Sun on June 21.
Therefore, it experiences less than 12 hours of daylight. Statement 4 (Arctic Circle) is correct:
On June 21, the Arctic Circle (66.5° N) experiences 24 hours of continuous daylight — known as the Midnight Sun phenomenon. Therefore, both the Tropic of Cancer and the Arctic Circle experience more than 12 hours of daylight on June 21st.

The climate described by these characteristics is most likely a Marine West Coast Climate (Cfb) according to the Köppen climate classification system. Annual and daily range of temperatures is low: Marine west coast climates are known for their mild temperatures year-round. The influence of the nearby ocean moderates both summer highs and winter lows, resulting in a smaller range of temperatures compared to continental climates at similar latitudes. Precipitation occurs throughout the year: These regions experience frequent precipitation due to prevailing westerly winds carrying moist air from the ocean. The cyclones associated with these winds bring rain or snowfall throughout the year. Precipitation varies between 50 cm and 250 cm: The amount of precipitation in marine west coast climates can vary depending on factors like latitude, topography, and proximity to the ocean. The range of 50 cm to 250 cm falls within the typical range observed in these regions.

* Donyi Polo Airport (Itanagar, Arunachal Pradesh): This newly constructed airport was inaugurated in 2022. It was built on undeveloped land, making it a greenfield project. * Kushinagar International Airport (Uttar Pradesh): This airport was inaugurated in 2021. It was also built as a new entity on undeveloped land, qualifying as a greenfield project. * Vijayawada International Airport (Andhra Pradesh): This airport has existed for several decades. While it has undergone significant expansion and modernization, it wasn't built from scratch on undeveloped land. Therefore, it's not a greenfield project. Therefore, only Donyi Polo Airport and Kushinagar International Airport are greenfield projects.