Answer: Climate change
Explanation:
UN Climate Action Summit 2019 was organized in 2019 to discuss the domain of global climate change research. According to this dangerous impact of climate will influence the growth of new generations to come. This included various participating organizations like World Meteorological Organization, Panel on Climate Change, Earth league and global framework, UN Environment, Global carbon project and others.
Rainwater picks up carbon dioxide from the air and as it percolates through the soil, which turns into a weak acid. This slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves.
Answer: <u>Aphotic</u><u> </u><u>zone</u>
less than 1% of sunlight penetrates the depths of the waters in the Aphotic zone
