The consequences could be serious if specifiers and customers don’t effectively assess the environmental impact of materials for use in marine civil engineering projects. That’s the conclusion of new life cycle analysis of pile planking commissioned from EY Climate Change and Sustainability Services by the Royal Netherlands Timber Trade Association (NTTA)/ Centrum Hout and FSC Netherlands.
The study focused on certified tropical timber species, but included exploratory assessment of the environmental impact of different materials in the same application. This found that, over a 30-year life cycle, use of certified wood sheet piles had lowest environmental impact. Depending on type of timber selected, recycled plastic impacts were up to four times as great, while a steel sheet pile wall came out worst, causing as much as 140 times the environmental damage as certified wood sheet piling alternatives.
The detrimental impacts of steel and plastic, including recycled, start at manufacturing. This both requires considerable energy and releases pollutants, which barely registered in the case of certified timber use.
“The LCA results confirm those of a 2013 study on cycle bridge construction, where certified wood also came out more favourably,” said Eric de Munck of NTTA/ Centrum Hout. “It’s not surprising since, in well-managed forestry, there’s hardly any environmental damage while, at the same time growing trees absorb CO2, helping reduce greenhouse effects.”
FSC Netherlands Director Liesbeth Gort said she was not surprised certified timber performed best in LCA, but was ‘amazed’ by the gulf in performance with steel and plastic.
“We know sustainable forest management is an effective tool to preserve forests, but the degree to which selecting the right material impacts climate gains is really surprising,” she said. “It’s important that local authorities, water boards and other clients and specifiers realise that.”
The pile planking LCA study was made possible by the European Sustainable Tropical Timber Coalition. For the executive summary of this and the earlier cycle bridge analysis click here.
Photo top by GWW Houtimport