Construction on one of the world's largest coal mines is set to begin in Australia after mining giant Adani received approval from Queensland's government. The controversial mine represents much needed economic prosperity for some towns and cities, and a huge environmental concern for opponents. Greg Navarro has more.

After years of delays and growing controversy over a plan to build Australia's largest thermal coal mine. The words Indian mining company Adani had been waiting to hear to begin to build the multi-billion dollar project.

LUCAS DOW CHIEF EXECUTIVE, ADANI AUSTRALIA "The construction period for the mine and rail project is essentially two years. So ostensibly you can be thinking from today in two years' time people should be expecting we have exported our first piece of coal."

That's welcomed news for Townsville mayor Jenny Hill, whose city has coming back from natural disasters over the years, including record setting floods just 4 months ago. But it hasn't been able to recover from a growing economic slump marked by high unemployment.

JENNY HILL TOWNSVILLE MAYOR "What we need are long term jobs."

Adani says the mine will produce more than 8,000 direct and indirect jobs across the region, including here in Townsville. But the project's sheer scale, and plan to extract billions of tonnes of coal worries environmentalists.

SHANI TAGER, GREAT BARRIER REEF CAMPAIGN MANAGER AUSTRALIAN MARINE CONSERVATION SOCIETY "The coal coming from this mine will be burnt in power stations which causes climate change which leads to hotter and warmer oceans."

Warming oceans have had a devastating effect on Australia's Great Barrier Reef, leading to recent bleaching events that have killed half of the corals here.

GREG NAVARRO TOWNSVILLE "Scientists say one of the more immediate concerns is an increase in shipping traffic which is expected to double if not triple - the result of transporting coal from the mine overseas, heading right across the Great Barrier Reef."

They warn that raises the risks for introducing invasive species, ship groundings on the reef, and increased dredging.

SHANI TAGER, GREAT BARRIER REEF CAMPAIGN MANAGER AUSTRALIAN MARINE CONSERVATION SOCIETY "The Great Barrier Reef is a great source of income and jobs for the people of Queensland. There is 64,000 people who work in industries related to the GBR in tourism for instance in Queensland so it does provide significant economic benefits already and we have to ask if we want to put those at stake for some shorter term jobs in a coal mine."

JENNY HILL TOWNSVILLE MAYOR "I have no doubt that the government will ensure that the conditions that are put on the mines that the mines are held responsible for maintaining those, living up to those conditions."

Hill is banking on the economic benefits to flow through her city for years to come. She says there are a handful of other mining companies looking to take up mining leases once Adani's project goes ahead. Greg Navarro, CGTN, Townsville.