Monitoring of the earth's climate has been carried out for over 100 years by several scientific organizations, including the World Meteorological Organization (WMO) and the U.S. National Oceanic and Atmospheric Administration (NOAA). Over this period, trends in the climate of the Earth have been observed and incorporated into predictive models. (Wikipedia, 2017) Climate change has been defined as a change in the statistical properties of the climate system, observed over long periods of time (defined as 10 years or more), regardless of cause. A number of factors can influence Earth's climate, including solar output, variations in Earth's orbit, volcanos, and changes in ocean currents. Scientists have identified human activities as a contributor to climate change. The consensus is that Earth's climate is warming, and it is "extremely likely" that this warming is caused by humans. (Wikipedia, Scientific opinion on climate change, 2017). It is likely that an increase in greenhouse gases in the atmosphere is a cause of this warming. Greenhouse gases include methane and carbon dioxide (CO,). These gases are released in the combustion of fossil fuels, release from decay of waste, and from activities such as breeding of livestock. The following graph, from the National Aeronautics and Space Administration, shows the global mean estimated temperature anomaly. in degrees Celsius, between 1880 and 2017