The less significant changes in pollutant levels represent diminishing returns on emissions reductions as the easier solutions have already been implemented. An argument for reducing regulations could be that substantial progress has been made and further stringent measures may not be cost-effective.
- The values to the right on the chart may represent less significant change in the levels of air-borne pollutants compared to the values to the left because earlier reductions could have been achieved where it was easier and less costly to do so.
- As policies become more stringent and the low-hanging fruit is picked, further reductions may be more difficult and expensive to achieve, leading to smaller percentage changes over time.
- Based on the information provided, an argument that could be made for reducing regulations regarding air quality is that significant progress has already been made in reducing emissions, as indicated by the substantial decline of certain key air pollutants from 2007 to 2012, with a drop of 740 million metric tons (MMT) a year, or a 12% reduction.
- The argument might focus on the economic impact of regulations, suggesting that continued stringent regulations at this point could impose unnecessary costs on businesses if the returns in terms of emission reductions are diminishing.