GLOBAL CLIMATE CHANGE

 
• Climate change means a change in climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods (UNFCC, 1992).

• Human induced increases of atmospheric concentration of gases e.g. CH₄, CO₂, N₂O, CFCs recognized as the cause of green house effect (absorption of infrared radiation by gases and its re-radiation back towards the earth’s surface) which result in unparalleled increases in global temperature.

• Measurements over the past 130 years show that atmospheric temperatures have risen considerably with the highest in the last few years.

• Volcanoes such as the eruption of mount Pira tubo in the Philippines in 1992 caused a drop in global temperatures but had no lasting effect on the trends in the global temperature.

• According to the researches, the International Panel on Climate Change issued its second Assessment Report in 1996 which indicated that under the IPCC business-as-usual scenario i.e. no reduction in CO₂ emissions; the atmospheric carbon dioxide concentration may increase from 350ppmv in 1993 to 525ppmv in 2050, resulting in 0.3^oc rise in global mean Temperature per decade.

• Recent climate models put the potential rise of the global mean surface temperature of about 1 to 3.5^oC by 2100. Mean temperature at the poles are expected to increase by 0.8 ^oC per decade and 0.1 ^oC per decade for the equatorial regions. Global mean sea levels are expected to rise by 6cm per decade resulting in increased salt water intrusion and loss of land and natural resources to the coastal regions.

• Global temperature rise is also predicted to increase frequency and destructiveness of hurricanes, more protracted droughts, longer and hotter heat waves, more severe rainy periods and significant changes in the area of the great ice sheets of Antarctica

• Ragupathy and Douglas (2009) assert that humans are currently releasing 70 million tones of CO₂ per day into the atmosphere and if this current rate should continue global air temperature could rise between 1.5 to 4.5 ^oC by the year 2100.

References

Mairéad, S. 2007: The Effects of Climate Change on Biodiversity. Submission Paper to the Dublin City Council policy Paper on Climate Change. 10pp

Ragupathy, K and Douglas, A.J. 2009: Effects of Climate Change on Global Biodiversity: A Review of Key Literature.

In Tropical Ecology 50 (1): 31-39. International Society for Tropical Ecology.www.tropical.com

UNCED, 1992: United Nations Conference on Environment and Development. Convention on Biological Diversity.1-33

UNFCCC, 1992: United Nations Framework Convention on Climate Change. 1-33