ANSWER:
1. A
2. A
3. B
EXPLANATION:
For the first question, Numerous studies have been conducted to investigate the impact of increasing CO2 levels on corals, and they all arrive at the conclusion that high CO2 levels make it difficult for marine organisms to create their calcium carbonate shells.
Coral reefs are likely to be affected by these changes because of their sensitive nature. They are sensitive to thermal stress and their ability to adapt to changing conditions is low. Research shows that an increase of 1 to 3°C in sea surface temperature will cause widespread mortality and more frequent bleaching (Bernstein et al. 2007).
For the second question, Refraction occurs when light goes through a water surface since water has a refractive index of 1.33 and air has a refractive index of about 1. The speed increases in the atmosphere.
For the third question, human activities keep increasing the effect of global warming. Global warming has a clearly observed, long term effect on Arctic sea ice. In fact, although climate models predict that Arctic sea ice will decline in response to greenhouse gas increases, the current pace of retreat at the end of the melt season is exceeding the models’ forecasts by around a factor of 3.
