Have you heard of the "Great Pacific Garbage Patch"? It seems ocean currents in the North Pacific had accumulated hundreds, if not thousands of plastic debris, in an area in the North Pacific that is hundreds of miles kilometers wide.
Most of the debris consists of small plastic particles suspended at or just below the water surface, and the debris zone move on a seasonal basis. It shifts as much as a thousand miles north and south, and drifts even farther south during periods of El Nino. It’s a floating garbage dump in the middle of the North Pacific.
As if mankind hasn’t done enough damage on land, now we are doing it to the oceans. Just imagine a garbage dump that is hundreds of miles kilometers wide! With pollution like this, there’s no need for a meteor to hit Earth. Humans will destroy the world long before that.