Lawley posted the image in the early hours of the morning to her Instagram account, and it has already garnered more than 1340 likes, and over 60 comments.
The mine in question - Queensland's Carmichael mine - has proposed to transport the coal via the Great Barrier Reef.
Lawley said in her caption, "Woke up this morning to find out that our Environmental minister and the Abbott government have approved what will be the biggest mine of Australia. Coal is soon going to be a dead commodity only bought buy [sic] irresponsible countries who do not care about climate change. I'm shocked and feel powerless."
Lawley then explained that millions of tonnes of seabed will have to be dredged and dumped in the World Heritage Area to make way for port expansions to service the mine.
The model also wrote that the company behind the operation had a dirty track record, explaining that in India, documents seized from [their] offices revealed the company was paying cash bribes to port officials, customs, police and local pollies in exchange for undue favour for illegal exports.