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 energy leaving Earth’s surface averages 390 W/m2. Why isn’t Earth cooling rapidly?
Even though the energy leaving Earth’s surface is more than twice that of the solar energy striking the Earth’s surface, Earth isn’t cooling rapidly because of Earth maintain her energy balance.
The emitted energy does not go directly out into space, but instead it is reabsorbed by clouds and gases in the atmosphere. Majority of the energy are reabsorbed by greenhouse gases such as methane, nitrous oxides, carbon dioxide etc. These greenhouse gases will constantly emit energy back into the atmosphere and keep the Earth a habitable temperature.
Ultimately, most of the energy will make its way out back into space and those that doesn’t are the ones responsible for the phenomenon known as global warming.
Q2) Decide and explain whether the statement is correct or incorrect. Explain.
The statement is incorrect. The winter mentioned in the cartoon is not due to the effect of higher average temperature caused by global warming but as a result of the effect of extreme weather and climate changes caused by global warming. Therefore, the issue of global warming is still more present than ever and we should not rest on our laurels.
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?
Water molecules will absorb the the microwave radiation and hence it the water molecules will rotate.However,this design is not successful during the WWII as the water molecules will interfere with the intended content that the radar device is suppose to detect.
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, air quality poses the most serious problem. Its effects can be seen in days. Even now, industrialised countries with many factories like China are already facing air pollution issues, with air quality reaching hazardous levels. People are already facing health problems and premature deaths due to air pollution. In Singapore, when mass burning of forests occur in Indonesia every year, air quality in Indonesia & neighbouring countries can reach dangerous levels and people fall ill as a result. Air pollution’s adverse effects on people’s health and productivity can be seen even now.
In the long run, I think that global warming poses the most serious problem. An increase in global temperatures can disrupt ecosystems. Rising sea levels also have the potential to lead to entire countries and islands becoming submerged under the sea. Extreme weather conditions can also pose threats to safety across the world. The agricultural sector may be the most affected because it is the most reliant on external weather conditions, which will lead to even more food source problems across the world on top of affecting the livelihood of many families depending on agriculture for a living.