Final answer:
The recognition of air pollution as an issue dates back approximately 2,000 years to ancient civilizations like Rome. The modern era has seen significant progress in reducing emissions, especially since the 1970s in the United States, with a current focus on renewable energy and energy efficiency to address ongoing health risks and environmental impacts.
Step-by-step explanation:
Acknowledgment of air pollution as a problem spans back around 2000 years, although it became a particularly prominent issue with the onset of the Industrial Revolution. Historical records from ancient civilizations, like Rome, indicate concerns over the burning of fuels and the air quality in cities. Writers such as Seneca the Younger complained about the polluted air in Rome, suggesting that the awareness of air pollution has been long-standing (Answer D: 2,000 years). The seriousness of the problem, however, has escalated significantly in recent centuries with industrialization, leading to heightened awareness and measures to combat the increase in air pollutants.
Since the 1970s, there has been tangible progress in reducing emissions. For instance, the United States has seen a significant decrease in emissions of certain pollutants, demonstrating that policies and technological advances can play an important role in mitigating the issue. The introduction of alternative energy sources, such as solar energy, and the efficient use of energy are ways to further reduce air pollution.
Nonetheless, it is evident that air pollution continues to pose a major health risk, affecting both the respiratory and circulatory systems and causing millions of deaths each year. This issue is particularly acute in countries with high poverty and population rates, where indoor air pollution from solid fuels is a major problem.