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4. To put the issue of global warming from the greenhouse effect in perspective it is important to understand 3 key factors:
a) Detailed data, shown in Figure, based on air extracted from ice cores drilled in the Antarctic ice cap, show that while we appear to be experiencing a peaking in the natural cycle of greenhouse gases and temperatures, we are actually adding man-made greenhouse gases to that peaking of the natural cycle.
b) CO2 levels in the atmosphere are at 380 parts per million. They have not been above 300 parts per million for at least 400,000 years. Further, data based on isotope ratios in marine micro fossils suggests strongly that CO2 levels have not in fact been above, or much above, 300 parts per million for about 23 million years. .
c) CO2 pumped into the atmosphere will remain there for 80 to 100 years and so will influence temperature and contribute to the greenhouse effect for long after its release. This means that that even if new emissions of carbon dioxide are reduced the overall concentration of CO2 will continue to increase as the continuing emissions combine with background levels.
The costs of inaction on this issue will lead to such visible impacts as increased health problems (tropical diseases spreading) and insurance costs, (increased occurrence of natural disasters), loss of land (with sea level rises), and a less stable climate.To put the issue of global warming from the greenhouse effect in perspective it is important to understand 3 key factors:
a) Detailed data, shown in Figure, based on air extracted from ice cores drilled in the Antarctic ice cap, show that while we appear to be experiencing a peaking in the natural cycle of greenhouse gases and temperatures, we are actually adding man-made greenhouse gases to that peaking of the natural cycle.
b) CO2 levels in the atmosphere are at 380 parts per million. They have not been above 300 parts per million for at least 400,000 years. Further, data based on isotope ratios in marine micro fossils suggests strongly that CO2 levels have not in fact been above, or much above, 300 parts per million for about 23 million years. .
c) CO2 pumped into the atmosphere will remain there for 80 to 100 years and so will influence temperature and contribute to the greenhouse effect for long after its release. This means that that even if new emissions of carbon dioxide are reduced the overall concentration of CO2 will continue to increase as the continuing emissions combine with background levels.
The costs of inaction on this issue will lead to such visible impacts as increased health problems (tropical diseases spreading) and insurance costs, (increased occurrence of natural disasters), loss of land (with sea level rises), and a less stable climate.
5. 1990’s warmest decade of the last millennium
1998 warmest year of the last millennium
All projections show at least 1.5 degrees of warming
2030: 0.4-2.0oC
2070: 1.5 - 6oC
1990’s warmest decade of the last millennium
1998 warmest year of the last millennium
All projections show at least 1.5 degrees of warming
2030: 0.4-2.0oC
2070: 1.5 - 6oC