**Montreal Protocol (1987):** An international treaty
designed to protect the **ozone layer** by phasing out
the production of numerous substances responsible for
ozone depletion, primarily **CFCs**.
**Ozone Depletion:** Occurs in the **stratosphere** where
UV-radiation splits Ozone ($\text{O}_3$) and is accelerated
by halogens (e.g., Chlorine) from CFCs. A $10\%$ loss in
$\text{O}_3$ leads to a $25\%$ increase in $\text{UVB}$
radiation.
**Kigali Amendment (2016):** An addition to the Montreal
Protocol to phase down the use of **HFCs**
(Hydrofluorocarbons), which are potent **greenhouse gases** but
do not deplete the ozone.
**Kyoto Protocol (1997):** An international treaty that
commits industrialized countries to **reduce greenhouse gas
(GHG) emissions** based on the principle of "common but
differentiated responsibilities."
**Global Warming/Greenhouse Effect:** Gases like
$\text{CO}_2$, $\text{CH}_4$, $\text{N}_2\text{O}$, and CFCs absorb
and re-emit long-wave (infrared) radiation, causing the
**Earth's surface temperature to rise**. Methane
($\text{CH}_4$) is $\mathbf{25}$ times more potent than
$\text{CO}_2$ over a 100-year period.
Theory summarized in bullet points for easy review.