It depends on which environment you mean. If you mean MY environment and YOUR environment then yes, Capitalism helps everyone through the voluntary exchange system. If you mean the weather and the whales, then, well, it could go either way. Harm to them doesn't stem from capitalism or communism (Soviet Russia had a very inefficient system for land distribution and food distribution) it stems from demographic. The United States has an anti-environmental policy in most areas (which I agree with and so do most people) but so do some communist countries. If anything, capitalism helps protect the natural environment through an inherent anti-waste system in which everyone has to pay for everything they use instead of just getting crap from the government. This helps people use less stuff (I don't care much about this issue but I do know a lot about it).
A profit driven society does not help, but harms the environment. When everyone is competing with each other to gain more and more profit, it end ups hurting the environment because people are taking shortcuts around environmental laws. If you are focusing on the environment, it will probably cut into your profits which a lot of people will not do.
The Deepwater Horizon oil spill is a good example of a profit-driven company which harmed the environment. The controversy surrounding the building of the Keystone pipeline is another example as environmentalists and concerned citizens protest the construction of a pipeline through the grainbelt of America. The oil industry is only one example of profit-driven companies, which are supported by certain segments of society, that are not environmentally conscious.