Question

Damage to the ozone layer by man-made chemicals has resulted in the appearance of ozone holes in the Arctic and the Antarctic in the spring season. International efforts have been made to curtail the production of ozone-depleting substances (ODS) such as chlorofluorocarbons (CFCs), yet the ozone holes continue to appear each year. What is the BEST explanation for the persistence of holes in the ozone layer? Elimination Tool Select one answer A In spite of agreements to lower ODS emissions, developed nations have mostly failed to do so. B While developing nations have reduced ODS emissions, those gains have been offset by increased emissions as developing countries industrialize. C The natural processes that repair the ozone layer are slow and it will take hundreds of years for any ozone depletion to recover. D CFCs can persist in the atmosphere for many years and CFCs released in the 20th century may continue to damage the ozone layer well into the 21st century.

Answer 1

The BEST explanation for the persistence of holes in the ozone layer is option D - CFCs can persist in the atmosphere for many years and CFCs released in the 20th century may continue to damage the ozone layer well into the 21st century. This is because CFCs are known to be long-lived in the atmosphere and can persist for several decades, even after production has been significantly reduced. As a result, CFCs released in the past continue to contribute to ozone depletion, and it will take many years for the ozone layer to fully recover, even with significant reductions in current emissions. Options A and B are not accurate because there have been significant efforts to reduce ODS emissions from both developed and developing nations, and emissions have been decreasing overall. Option C is also not accurate because the natural processes that repair the ozone layer can be quite rapid under certain conditions, and the rate of recovery depends on a number of factors, including the level of ongoing ODS emissions.