Answer and explanation:
<em>1. Which are true about changes in carbon dioxide in the Earth's atmosphere since 1860? Select the two correct answers.</em>
- The increases in carbon dioxide are caused by human activity.
- The rate of change in carbon dioxide is exponential.
Since the industrial revolution (~1860), the concentration of CO2 has been increased drastically. Industries mostly relied on the burning of fossil fuel (combustion) for energy purposes that produces a high proportion of CO2. This is evidence that human activities (anthropogenic) are the major cause of increased CO2 in the atmosphere.
<em>2. Which is evidence of climate-forced sea level rise?</em>
- Submerging of low islands and coastlines
It is a well-established fact that the increase in greenhouse gases is causing global warming which results in the melting of <u>ice caps</u>. The hight melting rate would ultimately lead to submerging/sinking of low islands and coastline. For example, it is a growing concern that the Maldives will be inundated in the near future and the people living there would have to move somewhere else. Similar things could happen to the other low islands.
<em>3. Which directly contribute to sea level rise?</em>
- expansion and melting of land ice
As discussed above, the melting of ice caps due to global warming would increase the water level in the oceans leading to sea-level rise. So, expansion and melting of ice is the direct cause. However, we know that the melting is triggered by an increased proportion of greenhouse gases, therefore, they are the indirect or secondary level causes.
<em>4. How does the ozone layer over the Arctic change with the seasons?</em>
- It peaks in winter and decreases in spring.
During winter, wind systems in the upper atmosphere and seasonal weather variations push ozone more toward poles (arctic), the low latitude areas (equator). This results in the condensation of ozone in the arctic. Furthermore, the sunlight intensity in the arctic is low during winter due to changes in Earth's orbit; hence, there is a less breakdown of ozone as well. The phenomenon starts reversing in early spring until summer. This is the reason that ozone concentration peaks in winter and starts decreasing in spring.
<em>5. How would a weaker jet stream help to cause extreme flooding?</em>
- It would create thicker clouds.
The weaker jet streams would allow developing low-pressure system on one side. This low pressure will firstly allow the development of a huge cloud system carrying intensive moisture content. However, winds from other areas would move to replace the low-pressure area and this results in a collision of two air masses leading to condensation. Usually, it results in heavy rainfall because the clouds in low pressure would carry a huge amount of water. In the case of the complete blocking event jet stream, the situation is even worst. For example, in 2010, the blocking of the jet stream over the Himalayan caused heavy rainfall in the northern Pakistan region leading to inundation in the whole country at a massive scale. For more information, you can read here in the article I published earlier (https://www.ajol.info/index.php/ajest/article/view/94950).
<em>6. Which choice gives the order of a chain of events that show cause and effect relationships that results from human activity?</em>
- increased carbon dioxide in the atmosphere; increased water vapor in the atmosphere; increase in severe storms; increase flooding
At first, the carbon dioxide content will increase due to human activities (e.g. burning of fossil fuels). Then, this will increase the temperature of that landmass (area) and finally increase the evaporation rate (water vapors in the atmosphere). This would result in increased cloud formation and severe storms because the warm air mass will move up due to low density and cold air mass will replace it. The cold air mass will bring more moisture content. Finally, a storm condition will establish and it will result in the intensive rainfall. The intensive rainfall will cause huge flooding or inundation in the area.
