What is the enhanced greenhouse effect?

Increases in the amount of carbon dioxide and other greenhouse gases in the Earth's atmosphere have caused an enhanced greenhouse effect.1 With emissions being produced daily, a large imbalance is being created which is enhancing the greenhouse effect and making it stronger. As there are naturally occurring greenhouse gases in the atmosphere that help keep the Earth warm, additional amounts of these gases leads to more heat being trapped on the planet. This extra heat is causing global warming as well as affecting the Earth's weather patterns.2

The greenhouse effect is a central component to keeping our Earth warm. This process maintains the temperature of the Earth such that the planet is warm enough to develop and sustain life.3 The preceding is true as long as the components of the greenhouse effect, the amount of light and energy coming from the sun as well as the quantity of greenhouse gases that are in the atmosphere, remain in balance.

Prior to the Industrial Revolution, which started in the 18th century, the components of the greenhouse effect were in balance, particularly the gases that circulated in the Earth's atmosphere. But once it got underway, increasing amounts of greenhouse gas emissions were created by humans.4 This was due to the growth in human activities such as the burning of fossil fuels, new industrial processes, deforestation and more extensive agriculture.

What causes the enhanced greenhouse effect?

The enhanced greenhouse effect is being caused by human activities that are adding greenhouse gases to the Earth's atmosphere. Today greenhouse gas levels are the highest they have been in the past 3 million years and have been increasing since the dawn of the Industrial Revolution.5 6

As there are already greenhouse gas emissions from natural sources, additional amounts leads to more heat being trapped on the planet. This extra heat creates an impact by distorting weather patterns and causing climate change.

Today, the enhanced greenhouse effect continues to grow by the addition of man-made greenhouse gas emissions to the Earth's atmosphere. Prior to the Industrial Revolution, the components of the greenhouse effect were in balance, particularly the gases that circulated in the atmosphere.

Once it got underway, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and fluorinated gas levels have been increasing because of humans activities. Below are some examples of these activities and their impact:

1. The burning of fossil fuels (such as natural gas, coal and oil) have added large quantities of CO2 into the planet's atmosphere. Fossil fuels are used to produce electricity, for transportation and in industrial production.7
2. Farming practices, such as intensive chemical soil fertilization, have led to the increase in CH4 and N2O levels in the air.8 9
3. Industry also produces and emits fluorinated gases such as hydrofluorocarbons (HFCs) perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). These are very strong greenhouse gases with many being more than a hundred times more powerful than CO2.10
4. Deforestation increases the amount of CO2 in the air, as there are less trees to absorb it through photosynthesis.7

What are effects of the enhanced greenhouse effect?

With an enhanced greenhouse effect, the Earth is unable to release enough heat to space which leads to global warming. Global weather patterns absorb some of this overall increase in temperature and adjust for this accumulation in energy. These two effects are now creating climate changes around the world.

Scientist have recorded a 0.75°C increase in the planet's overall temperature during the course of the last 100 years.11 12 The enhanced greenhouse effect leads to other effects on our climate and has already caused:

• Greater strength of extreme weather events like: heatwaves, tropical cyclones, floods, and other major storms.13 14 15 16
• Increasing number and size of forest fires.17 18
• Rising sea levels (predicted to be as high as two feet by the end of the next century).4 19
• Melting of glaciers and polar ice.20 21 22
• Increasing acidity in the ocean, resulting in bleaching of coral reefs and damage to oceanic wildlife.4 23 24

More info:
Greenhouse effect - Australian Department of the Environment
The Enhanced Greenhouse Effect - JNCC

• 1. Allison, Ian. The science of climate change: questions and answers. Canberra: Australian Academy of Science, 2010.
• 2. The Royal Society. Climate change: A Summary of the Science. London: The Royal Society Science Policy Centre, 2010.
• 3. U.K. Met Office. Warming: A guide to climate change. Exeter, U.K.: Met Office Hadley Centre, 2011.
• 4. a. b. c. Bernstein, Lenny, R. K. Pachauri, and Andy Reisinger. Climate change 2007: synthesis report. Geneva, Switzerland: IPCC, 2008.
• 5. "What Does 400 ppm Look Like?" Scripps Institution of Oceanography, UC San Diego. https://scripps.ucsd.edu/programs/keelingcurve/2013/12/03/what-does-400-ppm-look-like (accessed August 5, 2014).
• 6. R. S. W. Van De Wal, B. De Boer, L. J. Lourens, P. Köhler, and R. Bintanja. "Reconstruction of a continuous high-resolution CO₂ record over the past 20 million years." Climate of the Past 7, no. 4 (2011): 1459-1469.
• 7. a. b. Le Quéré, C., A. K. Jain, M. R. Raupach, J. Schwinger, S. Sitch, B. D. Stocker, N. Viovy, S. Zaehle, C. Huntingford, P. Friedlingstein, R. J. Andres, T. Boden, C. Jourdain, T. Conway, R. A. Houghton, J. I. House, G. Marland, G. P. Peters, G. Van Der Werf, A. Ahlström, R. M. Andrew, L. Bopp, J. G. Canadell, E. Kato, P. Ciais, S. C. Doney, C. Enright, N. Zeng, R. F. Keeling, K. Klein Goldewijk, S. Levis, P. Levy, M. Lomas, and B. Poulter. "The global carbon budget 1959–2011." Earth System Science Data Discussions 5, no. 2 (2012): 1107-1157.
• 8. Bousquet, P., S. C. Tyler, P. Peylin, G. R. Van Der Werf, C. Prigent, D. A. Hauglustaine, E. J. Dlugokencky, J. B. Miller, P. Ciais, J. White, L. P. Steele, M. Schmidt, M. Ramonet, F. Papa, J. Lathière, R. L. Langenfelds, C. Carouge, and E.-G. Brunke. "Contribution of anthropogenic and natural sources to atmospheric methane variability." Nature 443, no. 7110 (2006): 439-443.
• 9. Denman, K.L., G. Brasseur, A. Chidthaisong, P. Ciais, P.M. Cox, R.E. Dickinson, D. Hauglustaine, C. Heinze, E. Holland, D. Jacob, U. Lohmann, S Ramachandran, P.L. da Silva Dias, S.C. Wofsy and X. Zhang. Couplings Between Changes in the Climate System and Biogeochemistry. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2007.
• 10. Montzka, S.A., S. Reimann, A. Engel, K. Krüger, S. O’Doherty, and W.T. Sturges. Ozone-Depleting Substances (ODSs) and Related Chemicals, Chapter 1 in Scientific Assessment of Ozone Depletion: 2010, Global Ozone Research and Monitoring Project–Report No. 52, 516 pp., World Meteorological Organization, Geneva, Switzerland, 2011.
• 11. "Global temperatures." U.K. Met Office. http://www.metoffice.gov.uk/climate-change/guide/science/monitoring/global (accessed August 13, 2014).
• 12. Hansen, J., R. Ruedy, M. Sato, and K. Lo. "Global Surface Temperature Change." Reviews of Geophysics 48, no. 4 (2010): RG4004.
• 13. Coumou, Dim, and Stefan Rahmstorf. "A decade of weather extremes." Nature Climate Change 2, no. 7 (2012): 491–496.
• 14. Emanuel, Kerry. "Environmental Factors Affecting Tropical Cyclone Power Dissipation." Journal of Climate 20, no. 22 (2007): 5497.
• 15. Yu, Jia-Yuh, and Ping-Gin Chiu. "Contrasting Various Metrics for Measuring Tropical Cyclone Activity." Terrestrial, Atmospheric and Oceanic Sciences 23, no. 3 (2011): 303.
• 16. Elsner, James B., James P. Kossin, and Thomas H. Jagger. "The increasing intensity of the strongest tropical cyclones." Nature 455, no. 7209 (2008): 92-95.
• 17. Flannigan, Mike D., Meg A. Krawchuk, William J. De Groot, B. Mike Wotton, and Lynn M. Gowman. "Implications of changing climate for global wildland fire." International Journal of Wildland Fire 18, no. 5 (2009): 483.
• 18. Pechony, O., and D. T. Shindell. "Driving Forces Of Global Wildfires Over The Past Millennium And The Forthcoming Century." Proceedings of the National Academy of Sciences 107, no. 45 (2010): 19167-19170.
• 19. Church, John A., and Neil J. White. "Sea-Level Rise from the Late 19th to the Early 21st Century." Surveys in Geophysics 32, no. 4-5 (2011): 585-602.
• 20. Comiso, J.C., and D.K. Hall. "Climate trends in the Arctic as observed from space." WIREs Climate Change (2014): 5:389–409.
• 21. NASA's Jet Propulsion Laboratory / California Institute of Technology. "Key Indicators." Global Climate Change. http://climate.nasa.gov/key_indicators/#landIce (accessed August 16, 2014).
• 22. McMillan, M., A. Shepherd, A. Sundal, K. Briggs, A. Muir, A. Ridout, A. Hogg, and D. Wingham. "Increased ice losses from Antarctica detected by CryoSat-2." Geophys. Res. Lett. (2014): 41, 3899–3905.
• 23. Hoegh-Guldberg, O., A. Dubi, C. D. Harvell, E. Gomez, P. Greenfield, R. S. Steneck, A. J. Hooten, P. J. Mumby, M. E. Hatziolos, R. H. Bradbury, N. Muthiga, R. Iglesias-Prieto, C. M. Eakin, N. Knowlton, K. Caldeira, A. J. Edwards, and P. F. Sale. "Coral Reefs Under Rapid Climate Change And Ocean Acidification." Science 318, no. 5857 (2007): 1737-1742.
• 24. Anthony, K. R. N., D. I. Kline, G. Diaz-Pulido, S. Dove, and O. Hoegh-Guldberg. "Ocean Acidification Causes Bleaching And Productivity Loss In Coral Reef Builders." Proceedings of the National Academy of Sciences 105, no. 45 (2008): 17442-17446.