Evaluating solutions that reduce human impacts

Engineers and scientists design technologies and policies to reduce human impacts on Earth's systems, then evaluate them with data on how well they work, what they cost, and what side effects they have. Several solutions have clear track records. After scientists linked chlorofluorocarbons (CFCs) to the destruction of stratospheric ozone, the 1987 Montreal Protocol phased them out worldwide, and the ozone layer is slowly recovering, expected to return to 1980 levels over most of the world by about 2040 and over Antarctica by about 2066. In the United States, the 1990 Clean Air Act Amendments created a cap-and-trade market for sulfur dioxide from power plants, and together with scrubbers that remove the gas from smokestacks, this sharply reduced acid rain. Catalytic converters cut pollution from cars, and wastewater treatment plants keep sewage out of rivers. Other solutions are still being tested or scaled up, such as capturing carbon dioxide at power plants or directly from the air, restoring wetlands to absorb floodwater and filter pollutants, planting forests, farming methods that build soil carbon, and replacing fossil fuels with renewable energy. Good evaluations compare a solution with alternatives, look for unintended consequences (for example, some CFC replacements turned out to be powerful greenhouse gases, which a 2016 amendment began phasing down), and consider who benefits and who bears the costs. Designs are then refined as monitoring reveals problems and engineers improve efficiency and cut costs.

This explanation is AI-generated and can occasionally be wrong. 🚩 Report