ozonekriittisiä

Ozonekriittisiä is a Finnish term that translates to "ozone-critical" or "critical to the ozone layer." It refers to substances or activities that have a significant negative impact on the Earth's stratospheric ozone layer. The ozone layer is a region of Earth's atmosphere that absorbs most of the Sun's ultraviolet (UV) radiation.

The most well-known ozonekriittisiä substances are chlorofluorocarbons (CFCs) and halons. These chemicals, once widely used in refrigerants, aerosols, and fire extinguishers, contain chlorine and bromine atoms. When released into the atmosphere, they rise to the stratosphere and are broken down by UV radiation, releasing these atoms. These free atoms then catalyze the destruction of ozone molecules, leading to a thinning of the ozone layer, particularly over the polar regions, creating "ozone holes."

Scientific consensus and international agreements, such as the Montreal Protocol, have identified and regulated these ozonekriittisiä substances. The phasing out of CFCs and halons has led to a gradual recovery of the ozone layer, though it remains a subject of ongoing monitoring and concern. Human activities that release significant amounts of ozone-depleting chemicals are considered ozonekriittisiä.