I don't buy into the huge percentages of human-induced global warming as the chicken little scientists report. There's no doubt that mankind generates its fair share of emissions into the atmosphere and waters but the end effect is pale compared to what nature pulls on us from time to time. You could have every automobile/truck on this planet running all at the same time for 48 hrs. and it still won't add up to what's spewed from a volcanic eruption like Mt. St. Helens or similar. That volcanic eruption altered the earth's atmosphere for an entire year as particles were suspended, creating a myriad of effects from stark sunsets to overcast skies and smog-like air. What needs to greatly decrease is the removal of trees and vegetation across the globe, esp. the rain forests. Those are the planet's 24/7 atmospheric cleaners. It truly urks me when I see a wooded area get stripped clean, developed for a housing project, strip plaza, or industry, only to last several years and then get abandoned. The only thing that roots from the abandonment are weeds. Local governments try to rekindle the blighted areas but often they are unsuccessful.