Is Big Labor Green?

Ezra Klein asserts that unions "push back on business models that they don’t consider sustainable for their workers or, increasingly, for the environment." Wilkinson counters:

Private-sector unions and big business come to blows over a cutting-the-cake problem. But the interests of labour and capital are aligned when it comes to the size of the shared cake. ... I think you'll find that unionised coal miners are as unenthusiastic as the coal companies they work for about regulations that would restrict the growth of mining operations or reduce demand for coal.