"The environment" or "earth" to us usually refers to the thin film covering the planet. Cells thick if the earth were a bowling ball, to use an old analogy.
If this film varies by a ridiculously small amount (in relation to cosmic specs) in temperature, chemistry, pressure, etc. we all die. We definitely have an effect on that "environment". And after all, isn't that the only one that matters? Do you really care about your kids' kids' kids' x 10^10th? Very little chance we will be around that long.
In the "meantime", I think we should figure out how to launch pollutants at a velocity to get them deep in the solar system. The hardest part is getting them into orbit. After that it's cake.