Environment & Climate Change terms for UPSC Prelims And Mains

Glossary Of Environment And Climate Change Terms

Abrupt Climate Change

An abrupt climate change is considered to be a change that takes place within a period of time that is fast relative to the cause of the change. For example, the climate change caused by the eruptions of Krakatoa changed the global climate within a year. This was abrupt given that the change was only possible once the volcanic ash had circulated throughout the atmosphere.



Adaptation means anticipating the adverse effects of climate change and taking appropriate action to prevent or minimise the damage they can cause, or taking advantage of opportunities that may arise. It has been shown that well planned, early adaptation action saves money and lives later.

Examples of adaptation measures include: using scarce water resources more efficiently; adapting building codes to future climate conditions and extreme weather events; building flood defences and raising the levels of dykes; developing drought-tolerant crops; choosing tree species and forestry practices less vulnerable to storms and fires; and setting aside land corridors to help species migrate.

National adaptation programmes of action (NAPAs)

In 2001, at COP 7 in Marrakesh, Parties acknowledged the specific needs of least developed countries (LDCs), in that they are least capable of dealing with the adverse effects of climate change, and adopted a dedicated package of decisions to support them. The LDC work programme includes, among other things, national adaptation programmes of action (NAPAs). Through their NAPAs, the LDCs identify priority activities that respond to their urgent and immediate adaptation needs. The Least Developed Countries Fund (LDCF) was established to support the programme’s implementation. The LDCs are also supported by a Least Developed Countries Expert Group (LEG) that provides technical support and advice.

National Adaptation Plans

The COP established the national adaptation plan (NAP) process at COP 16 (2010) to enable Parties to formulate and implement NAPs as a means of identifying medium- and long-term adaptation needs and developing and implementing strategies and programmes to address those needs. It is a continuous, progressive and iterative process which follows a country-driven, gender-sensitive, participatory and fully transparent approach. In order to enhance the availability of adaptation support, the COP in 2015 requested the Green Climate Fund to expedite support for the formulation and implementation of national adaptation plans.



Aerosols are minute particles suspended in the atmosphere. When these particles are sufficiently large, we notice their presence as they scatter and absorb sunlight. Their scattering of sunlight can reduce visibility (haze) and redden sunrises and sunsets.

Aerosols interact both directly and indirectly with the Earth’s radiation budget and climate. As a direct effect, the aerosols scatter sunlight directly back into space. As an indirect effect, aerosols in the lower atmosphere can modify the size of cloud particles, changing how the clouds reflect and absorb sunlight, thereby affecting the Earth’s energy budget.



Afforestation is the process of introducing trees and tree seedlings to an area that has previously not been forested. Afforestation can be done through tree planting and seeding, naturally or artificially.

Similarly, reforestation can be considered a form of afforestation. Reforestation is the alteration of a non-forested area to a forested area through tree planting and seeding. The difference is that reforestation is the restoration of an area that has been deforested.


Annex I Countries/Parties

Annex I Parties include the industrialized countries that were members of the OECD (Organisation for Economic Co-operation and Development) in 1992, plus countries with economies in transition (the EIT Parties), including the Russian Federation, the Baltic States, and several Central and Eastern European States.

Annex II Parties consist of the OECD members of Annex I, but not the EIT Parties. They are required to provide financial resources to enable developing countries to undertake emissions reduction activities under the Convention and to help them adapt to adverse effects of climate change. In addition, they have to “take all practicable steps” to promote the development and transfer of environmentally friendly technologies to EIT Parties and developing countries. Funding provided by Annex II Parties is channelled mostly through the Convention’s financial mechanism.

Non-Annex I Parties are mostly developing countries. Certain groups of developing countries are recognized by the Convention as being especially vulnerable to the adverse impacts of climate change, including countries with low-lying coastal areas and those prone to desertification and drought. Others (such as countries that rely heavily on income from fossil fuel production and commerce) feel more vulnerable to the potential economic impacts of climate change response measures. The Convention emphasizes activities that promise to answer the special needs and concerns of these vulnerable countries, such as investment, insurance and technology transfer.



We live at the bottom of an invisible ocean called the atmosphere, a layer of gases surrounding our planet. Nitrogen and oxygen account for 99 percent of the gases in dry air, with argon, carbon dioxide, helium, neon, and other gases making up minute portions. Water vapor and dust are also part of Earth’s atmosphere. Other planets and moons have very different atmospheres, and some have no atmospheres at all.

The atmosphere is so spread out that we barely notice it, yet its weight is equal to a layer of water more than 10 meters (34 feet) deep covering the entire planet. The bottom 30 kilometers (19 miles) of the atmosphere contains about 98 percent of its mass. The atmosphere—air—is much thinner at high altitudes. There is no atmosphere in space.