This is taken from their website.

"The British National Party is this nation’s only true Green party which has policies that will actually save the environment.

Unlike the fake “Greens” who are merely a front for the far left of the Labour regime, the BNP is the only party to recognise that overpopulation – whose primary driver is immigration, as revealed by the government’s own figures – is the cause of the destruction of our environment."

ah, of course!