We can’t clean the air in western USA period, because “any reduction in our emissions may be offset by the pollution” from Asia.
“China, the world’s most populated country, has experienced rapid industrial growth, massive human migrations to urban areas, and considerable expansion in automobile use over the last two decades. As a result, the country has doubled its emissions of man-made pollutants to become the world’s largest emitter of tiny particles called pollution aerosols that are transported across the Pacific Ocean by rapid airstreams emanating from East Asia.”
Almost 40 billion pounds of pollution is exported over the ocean each year with nearly 10 billion pounds deposited on North America….
But not all imported aerosol pollution can be blamed on China and Asia. Satellites also show that pollution in western USA originates as far away as Europe. Delivered around the earth, even small particles from our eastern states pollute the air of the west coast!