Chemical substance, found mainly in liquid coolants, that damages the earth's protective ozone layer.
The primeval supercontinent, hypothesized by Alfred Wegener, that broke apart and formed the continents and oceans as we know them today.
Process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches.
Pacific Ring Of Fire
Ocean-girdling zone of crustal instability, volcanism, and earthquakes resulting from the tectonic activity along plate boundaries in the region.
The most recent epoch of the late cenozoic ice age, beginning about 1.8 million years ago and marked by as many as 20 glaciations and interglacations of which the current warm phase.
A period of global cooling during which continental ice sheets and mountain glaciers expand.
The most recent glacial period of the Pleistocene, enduring about 100,000 years and giving way, beginning about 18,000 years ago, to the current interglacial, the Holocene.
The current interglaciation period, extending from 10,000 years ago to the present on the geologic time scale.
Little Ice Age
A century-long period of cool climate that began in the 1590s. Its ill effects on agriculture in northern Europe were notable.
The threat to environmental security by human activity such as atmospheric and groundwater pollution, deforistation, oil spills, and ocean dumping.
The natural process by which water is purified and made fresh through evaporation and precipitation. The cycle provides all the fresh water available for biological life.
Subterranean, porous, water-holding rocks that provide millions of wells with steady flows of water.
An increase in the average temperature of the earth's atmosphere (especially a sustained increase that causes climatic changes)
Rain containing acids that form in the atmosphere when industrial gas emissions (especially sulfur dioxide and nitrogen oxides) combine with water.
Cycle whereby natural processes and human activity consume atmospheric oxygen and produce carbon dioxide and the Earth's forests and other flora, through photosynthesis, consume carbon dioxide and produce oxygen.
Non-liquid, non-soluable materials ranging from municipal garbage to sewage sludge; agricultural refuse; and mining residues.
Disposal sites for non-hazardous solid waste that is spread in layers and compacted to the smallest practical volume. The sites are typically designed with floors made of materials to treat seeping liquids and are covered by soil as the wastes are compacted and deposited into the landfill.
Hazardous-waste-emitting radiation from nuclear power plants, nuclear weapon factories, and nuclear equipment in hospitals and industry.
The diversity of plant and animal life in a particular habitat (or in the world as a whole)
A layer in the stratosphere (at approximately 20 miles) that contains a concentration of ozone sufficient to block most ultraviolet radiation from the sun.
Vienna Convention for the Protection of the Ozone Layer
The first international convention aimed at addressing the issue of ozone depletion. Held in 1985, the Vienna Convention was the predecessor to the Montreal Protocol.