Unit 3: Application Exercise

Application Exercise 4

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/m²Why isn’t Earth cooling rapidly?

The amount of energy emitted by the Earth’s surface is more than double of the incident solar energy on the Earth as the atmosphere absorbs and retains this emitted heat energy, keeping the Earth’s energy balanced.

Q2. “This winter has lowered my concerns about global warming…”. Decide and explain where the stamen is correct or incorrect. Explain.

The stamen is incorrect. Weather is measured over minutes, hours, days or seasons while climate change is measured over a period of more than 30 years. Hence, a lower temperature during the winter does not mean that the Earth is cooling.

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

The atmospheric water molecules surrounding the radar devices absorbed the microwave radiation, triggering the molecules to rotate rapidly and converting electrostatic potential energy to thermal energy. This interfered with the detection of intended objects, making the radar devices pointless.

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 (pick one and explain)? In the long run (pick one and explain why)?

In the short run, deteriorating air quality will be of the largest concern. Worsening air pollution (eg. haze) affects us directly as it leads to health problems such as cardiovascular and respiratory problems.

In the long run, depleting stratospheric ozone will be the most severe problem. As the ozone layer depletes, more UV rays penetrate and reach the Earth’s surface. Exposure to higher amounts of UV radiation leads to irreparable damage to the ecosystem. For example, the human health is adversely affected through increased risk of skin cancer, cataracts and weakening immune system; reduced agriculture as crops are more vulnerable to increased UV radiation; threatening of marine life and animals due to disruptions in food chains and reproduction cycles.