Duration :
The speaker gives a brief explanation of why greenhouse warming is a serious concern. They discuss the existence of the greenhouse effect and how it is necessary for life on Earth. However, with the increasing abundance of greenhouse gases such as water vapor, carbon dioxide, methane, and freons, the Earths atmosphere is becoming more fragile and vulnerable to human activity. The temperature of the Earth has been increasing steadily throughout the 20th century, and computer models predict that it will continue to do so in the coming decades. The speaker suggests that relying on a deus ex machina to correct the problem is unlikely and emphasizes the importance of taking action to mitigate the effects of greenhouse warming.