Q1. Understanding Earth’s energy balance is essential to understanding the issue of global    warming. For example, the solar energy striking Earth’s surface averages 168 watts per square meter (W/m2), but the energy leaving Earth’s surface averages 390 W/m2. Why isn’t Earth cooling rapidly?

Ans: The atmosphere retains much of the energy emitted from the surface. This is known as the greenhouse effect.

Q2. Do you think the statement made by the cartoon is justified? Explain.

      “ This winter has lowered my concerns about global warming.”

Ans: Firstly, global warming is a global issue, we should not only concern about the weather           of a certain region. Even if we focus on a certain region, the duration of winter or the      temperature might also be different, which are so-called symptoms of the global warming.

Secondly, global warming is a long-term issue, we cannot identify the difference in a short period of time comparing in terms of decades or centuries.

Q3. One of the first radar devices developed during World War Two used microwave radiation of a specific wave range that triggers the rotation of water molecules. Why was the design not successful?

Ans: While using radar in rainy days or in the sea war, where has a high concentration of water vapor, the microwave would contribute to the rotation of water molecules instead of conveying information. The energy of microwave is transformed into energy of water molecules (possibly heat). So the design is unsuccessful.

Q4. Now that you have studied air quality (Unit 1), stratospheric ozone depletion (Unit 2), and global warming (Unit 3), which do you believe poses the most serious problem for you in the short run? In the long run?

Ans: Short run-air quality: It relates the most to our daily life because we breathe everyday. All the smoke, soot, dust and etc will definitely affect directly to our health.

Long run-global warming: As the temperature keeps rising up, the Earth would not be suitable for living any more. And high temperature causes the sea levels to rise, as a result, some parts of land which may has large populations will submerge under water.