As far as the environment of Antarctica is concerned, there have been the discovery of a large Antarctic ozone hole in the earth's stratosphere (the ozone layer) - first announced in 1985 - spurred the signing of the Montreal Protocol in 1987, an international agreement phasing out the use of ozone-depleting chemicals; the ozone layer prevents most harmful wavelengths of ultra-violet (UV) light from passing through the earth's atmosphere; ozone depletion has been shown to harm a variety of Antarctic marine plants and animals (plankton); in 2016, a gradual trend toward "healing" of the ozone hole was reported; since the 1990s, satellites have shown accelerating ice loss driven by ocean change; although considerable uncertainty remains, scientists are increasing our understanding and ability to model potential impacts of ice loss. As for nvironment - international agreements, we have; .