The W[orld] B[usiness] C[ouncil for] S[sustainable] D[evelopment] believes that green taxes can deliver environmental improvements, "in some circumstances". But the companies also note that tax exemptions can function like payments for ecosystem services to reward positive conservation efforts. "The difference is that the PES is a direct payment for a service, whereas the exemption is effectively a non-payment (of monies that would otherwise be due as tax)".
via www.euractiv.com
The simple economics are simple: a marginal tax on an undesirable action is the equivalent of a marginal subsisdy on (payment for) the anti-undesirable action. But, as usual, my guess is that the real world is more complicated than simple economics world and nonpayments (tax exemptions) for not screwing up the environment are not the equivalent of a direct payment for ecosystem services.