Argon Argon Argon is a chemical element with symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in the Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abundant as water vapor (which averages about 4000 ppmv, but varies greatly), 23 times as abundant as carbon dioxide (400 ppmv), and more than 500 times as abundant as neon (18 ppmv). Argon is the most abundant noble gas in Earth's crust, comprising 0.00015% of the crust. Nearly all of the argon in
Migration of marine species in the Northern Atlantic Ocean Migration of marine species in the Northern Atlantic Ocean The world's oceans are warming due to climate change. Climate change is caused by three major factors which are the greenhouse effect, variation in the sun's energy that reaches Earth, and changes in reflectivity within Earth's atmosphere and its surface. The greenhouse effect is caused by greenhouse gases that absorb sunlight. Energy from the sun that reaches Earth is either retained or sent into space. Greenhouse gases in Earth's atmosphere such as carbon dioxide, methane, and water vapor absorb energy which cause a blanketing effect that warms the earth. Aerosols such