We have changed the face of the planet and the plants that grow on much of the earth. We have also affected the percentage of gasses in the air. It seems probable that what grows on most of the planet and makes up the atmosphere might affect weather and climate.
Ditto Rah. When you see 26.8 billion tons of Co2 released antropogenically vs. only 200 million tons annually by volcanoes it becomes quite clear that man is indeed capable of changing earth's atmophere.
http://hvo.wr.usgs.gov/volcanowatch/archive/2007/07_02_15.htmlTo me it's quite obvious how we've shaped and dominated the earth when I fly at night at 30,000 feet and see how much of the U.S. is lit up, and we aren't even the earth's most densely populated country.
At least fish aren't capable of nuclear weapons after they overeat their food supply.