Plastic bottles vs aluminium cans: Who'll win the global water fight?
Water pollution: Aluminium vs plastic
Global bottled water giants are ramping up trials of easily recyclable aluminium cans to replace plastic that pollutes the world's seas. Sound like a slam-dunk for the environment? Not entirely. Aluminium cans might indeed mean less ocean waste, but they come with their own eco-price: the production of each can pumps about twice as much carbon into the atmosphere as each plastic bottle.
What's the challenge?
By increasing recycling via cans, companies could fall back in efforts to reduce their carbon footprints, illustrating the tough juggling act they can face to keep environmentally conscious investors, campaigners and consumers on-side. "That's the dilemma you're going to have to choose between,” said Ruben Griffioen, sustainability manager of packaging materials at Heineken, adding the company was trying to reduce both plastic waste and emissions.
Aluminium- a greener alternative?
Recycling plastic is more complex, leads to degradation and has lower reuse rates than aluminium - so the metal has been heralded as a greener alternative. Cans have on average 68% recycled content compared to just 3% for plastic in the United States, Environmental Protection Agency data shows. Comparing the carbon footprints of aluminium and plastics is a complex calculation because making the metal with hydropower instead of fossil fuels reduces emissions while using recycled aluminium slashes it even further. But when all types of metal are averaged out, however, can still account for about double the greenhouse gases of plastic bottles, Barrow said, citing figures for Europe. At aluminium's most polluting level, a 330 ml can is responsible for 1,300 grams of carbon dioxide emissions, according to the analysis compiled for Reuters, roughly equating to the emissions produced by driving a car 7 to 8 km. A plastic bottle of the same size, made from the polyethene terephthalate (PET) plastic typically used, accounts for up to 330 grams.
'Never that clean'
Bruce Karas, an executive at Coca-Cola North America in a change of environment and sustainability, acknowledged the conflicting environmental pressures at play. "When we look at a different material, you look at all of the levers: the carbon footprint, consumer preference, energy, water," he said. "There's a mix, there are some things that are not that desirable, but if you have five good things and one that isn't, we'll all have to make decisions. "It'll never be that clean." So aluminium has a larger footprint in production because of the vast power needed in the smelting process. But, in a further example of the complexities of environmental impact, the overall carbon equation becomes more muddied when other issues such as logistics are taken into account. "It's a complex picture, certainly," said Simon Lowden, an executive who leads Pepsi's plastics drive. "You have to think about transport, secondary packaging, time in-store, all those considerations come into play." Because aluminium is lightweight and can make efficient use of space, less transport is usually needed than for plastics or glass, while less power is also needed to chill drinks in cans - particularly useful in tropical climes. "That means in some markets aluminium would actually not produce as much greenhouse gas," Lowden said.
Plastic strikes back
But while cans could well carve out a niche within the $19 billion-a-year bottled water industry, they are unlikely to sweep the board anytime soon, if ever, industry experts say. Simple economics is a major factor; aluminium is more expensive than plastic - the raw material cost for a can is about 25-30% higher than a PET bottle of a similar volume, according to analyst Uday Patel at consultancy Wood Mackenzie.
A rise in the cost of products?
A broad shift to aluminium cans would raise costs for drinks companies, also including new manufacturing infrastructure, some of which are likely to be passed on to consumers, thus hitting products' competitiveness against plastic rivals.
How often do people down bottles of water in one go? While advances are being made in can technology, most cans are opened and stay open, while bottles can be recapped. Plastic water bottles can also be sold in a range of sizes, while cans are more limited. As a result of such factors, drinks giants are cautious. In an example of this toe-in-the-water approach, Coke is planning a limited launch of its top U.S. water brand Dasani in aluminium cans and aluminium resealable bottles later this year. Even while companies are beginning to sell water in cans, to assuage pollution concerns, they are also embarking on a green makeover for plastic. Scientific efforts include creating new compounds that are biodegradable or more easily recyclable.
Another obstacle to a large-scale shift from plastic bottles is that there may not be enough cans to go round, at a time when some beers and wines are also switching from glass to cans. The world's top can maker Ball Corp, which supplies the likes of Coke and Pepsi, is already scrambling to add capacity to meet demand.