In summary, scientists think rising levels of greenhouse gases such as carbon dioxide and methane in the atmosphere are contributing to global warming, as would be expected; but to what extent is difficult to conclude at the present time. ...

• Word Count: 573
• Approx Pages: 2
• Grade Level: Undergraduate

Global warming is the gradual increase in the earth's average temperature of the atmosphere, which in the long history of the earth has occurred naturally but within the last century or so humans have now started to heat up the globe through their activities. At first thought it seems outrageous to...

• Word Count: 669
• Approx Pages: 3
• Has Bibliography
• Grade Level: Undergraduate

Fred Singer, and Willie Soon, who established in their "Summary of Policymakers" that temperatures have not changed in parallel with CO2 levels and consequently, humans cannot be responsible for any climate change. ...

• Word Count: 1059
• Approx Pages: 4
• Has Bibliography
• Grade Level: Undergraduate