The Earth's atmosphere is divided into several layers based on temperature profiles. Starting from the surface, the order is the troposphere (1st), stratosphere (2nd), mesosphere (3rd), and thermosphere (4th). The mesosphere is characterized by decreasing temperatures with altitude and is where most meteors burn up upon entry.

The Antarctic Circle is a circle of latitude on the Earth at approximately 66.5 degrees south of the Equator. It marks the southernmost latitude where the sun can remain continuously above or below the horizon for 24 hours, a phenomenon known as the midnight sun or polar night.

Coordinated Universal Time (UTC) is the primary time standard by which the world regulates clocks and time. It was historically referred to as Greenwich Mean Time (GMT), which was based on the mean solar time at the Royal Observatory in Greenwich, London. While GMT is still used in some contexts, UTC is the modern scientific standard.

A galaxy is a vast system of stars, gas, dust, and dark matter held together by gravity. While the Milky Way is a specific example of a galaxy, the general term for such a collection of stars is a galaxy.

CFCs are highly stable synthetic compounds that do not break down easily in the lower atmosphere. Due to their chemical stability, they can persist in the atmosphere for decades, with various types of CFCs having atmospheric lifetimes ranging from approximately 22 to over 100 years.

Global warming disrupts established climate patterns, leading to more frequent and intense extreme weather events. These include severe droughts in some regions due to altered precipitation patterns and increased flooding in others caused by heavy rainfall or rapid glacial melting. These changes pose significant risks to ecosystems, agriculture, and human settlements worldwide.

Climate is defined as the statistics of weather over a long period, typically 30 years or more. While weather refers to the short-term state of the atmosphere at a specific time and place, climate provides a broader, long-term perspective on the expected environmental conditions of a region.

The rapid melting of ice sheets and glaciers leads to habitat loss for polar species, such as polar bears and penguins, which rely on ice for hunting and breeding. This disruption of ecosystems threatens biodiversity and forces species to adapt or face extinction as their natural environments disappear.

Rising sea levels pose a severe threat to coastal regions globally. The inundation of low-lying areas leads to the displacement of populations and the destruction of human settlements. While infrastructure damage and species endangerment are also significant impacts, the direct displacement of communities is a primary humanitarian concern.

Climate change is driven by various anthropogenic activities. Deforestation releases stored carbon, agricultural practices emit methane and nitrous oxide, and the use of aerosol products can release harmful gases into the atmosphere. Collectively, these actions increase the concentration of greenhouse gases, trapping heat and altering the Earth's climate systems, leading to long-term environmental consequences.