With global shipping trade expected to double by 2030 or earlier and mega-cruise ships transiting protected waters such as the Great Barrier Reef and Antarctica, ocean pollution and global warming emissions from ships and ports are growing at an alarming rate in Australia and around the world.

Globally, ships now produce as much as double the climate change gases of commercial aviation and about three percent of global carbon dioxide emissions.

While ships are energy efficient compared to trucks and rail, regulation of marine fuels and engines lag decades behind. Just one ship pulling into port can pollute as much as 350,000 cars in one hour.

About 3,500 international vessels made more than 10,000 calls on Australian ports in 2005-06 -- and many more are headed this way due to port expansions.

Every major Australian port is expanding, including Newcastle, Sydney, Botany Bay, Brisbane, Melbourne, and Fremantle, to accommodate more and larger cargo and cruise ships. Most of these are occurring without requiring ships to use cleaner fuels or engines or banning dumping of sewage, graywater, garbage from crews and passengers into harbors and coastal waters.

Cruise ships carrying 3,000 or more people generate more on-board waste than any other type of vessel. On a one-week voyage, a typical cruise ships produces 50 tons of garbage, one million gallons of graywater, 210,000 gallons of sewage, and 35,000 gallons oily bilge water.  Almost everything goes overboard – sometimes treated, sometimes not.

The cruise industry is dominated by two corporations, Carnival and Royal Caribbean, which own all of the big-name cruise lines. Together they have been fined more than US$50 million for illegal dumping of oily water, sewage, and garbage in US jurisdictions alone.

Last season in Antarctica, expedition leaders documented garbage dumping from a so-called eco-tour vessel. The incident was first denied, then forgotten without any penalty from the international bodies authorised to protect the region.

Port officials in Fremantle, Sydney and Brisbane told me that they ban cruise ship discharges in their port, but it is not clear how this is enforced or monitored. Port-specific policies send a strong message to the cruise lines that they can't dump, but it doesn't stop the discharge of contaminated sewage or raw graywater just outside the breakwater. What's needed is national legislation banning all cruise ship dumping in Australian waters.

Ships and ports can be made much greener with use of cleaner fuels, engines, ship designs, technologies and operations. With pressure from environmental and community activists (and lawsuits), governments in California, Sweden and Europe are jump-starting the greening of the world's ports and merchant fleets through regulations requiring cleaner ships.

To protect Australia's air and water from shipping and cruise pollution, ships must use cleaner marine distillate fuels in port and coastal waters and plug into shoreside power at the dock. All ship dumping of wastewater and garbage should be banned within the territorial sea out to 12 miles and shoreside disposal should be required.

Friends of the Earth is advocating for greener ships and ports at the international level, but it will take port-by-port and state-by-state action to achieve a global change. To stay informed and help watchdog the world's ports, keep an eye on my blog, <www.portwatch.net> or contact me directly at <tshore@foe.org>.

Teri Shore is Campaign Director for Clean Vessels at Friends of the Earth in the US.