Causes of Global Climate Change: Global Warming

Sunlight received by the Earth may be reflected by either the atmosphere or the surface. Some of the light is absorbed by the Earth and re-emitted as infrared energy (heat). Gases, both natural and artificial in origin, prevent some of this heat from escaping to space thereby causing the Earth to grow warmer. Global temperatures are 0.6ºC higher today than they were 100 years ago.

Temperatures of the northern hemisphere for the past 1000 years (from Mann, 1999)


Image source: NOAA National Climatic Data Center, State of the Climate: Global Analysis for Annual 2013, published online January 2014, retrieved on May 16, 2015 from http://www.ncdc.noaa.gov/sotc/global/201313.

Gases that cause the global warming (greenhouse effect)

Carbon dioxide (CO₂) - most CO₂ today comes from the burning of coal, oil, natural gas, and wood. CO₂ content of the atmosphere is 25% higher than pre-industrial levels.

Methane - Atmospheric methane is 100% higher than pre-industrial levels.

Chlorofluorocarbons - This gas was widely used in refrigerators and air conditioners, but it was banned when it was discovered that it causes both global warming and destruction of the ozone layer

Effects of Global Warming

The impact on the Earth is uncertain. Scientists are unable to precisely model the nature of this process. General atmospheric warming due to human pollution is highly probable. Polar ice caps may partially melt raising sea level. Some parts of the land may receive less rain while others receive more.


Image source: Our Changing Climate: Southeast

Some Solutions To The Global Warming Problem

1. Use Energy More Efficiently - Practice conservation in every way possible.


2. Develop Alternate Energy Sources - Solar energy is ideal in this regard, as are hydroelectric, wind, and geothermal power. Increased reliance on nuclear power is a possibility, however, the disposal of nuclear waste and other dangers create considerable concern.


3. Other Strategies
• Improve public transit to reduce automobile use
• Create market incentives to use other energy sources by taxing the use of carbon products
• Reverse the world-wide trend toward deforestation
• Modify your life style so as to minimize impact on the environment

Serious Concerns

1. The developed countries achieved their wealth on fossil fuels. How can we deny developing nations these same benefits?


2. Deforestation is a short-term benefit to the logging industry and farmers around the world. How can we prevent them from making a living?


3. China has huge coal deposits that will be used to support a huge population. How can they be encouraged to develop other energy sources?


4. Many poor coastal countries will suffer greatly from a sea level rise and yet they produce very little carbon pollution. What obligations do the rich countries have to those who will suffer because of the pollution of others?

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