Life cycle assessment, the one sure measure of sustainability
Published Tuesday, November 7, 2017 in the New Brunswick Telegraph Journal and the Fredericton Daily Gleaner.
At first glance, that organic produce in your favourite grocery store may seem to be the most eco-friendly option you can buy. But is it really?
What if it’s over-packaged in some non-recyclable material? What if it’s shipped halfway across the planet? What if it’s so perishable that much of it spoils en route?
Suddenly, what seems like a simple choice isn’t simple anymore – demonstrating why life cycle assessment (LCA) is such an important tool in determining the true sustainability of any product.
What it is
LCA is a method of measuring the total environmental impact of a product, from its origin to its end. It takes into account everything from the raw materials used in production to the end-of-life disposal of the product, plus energy and inputs used at all steps in between.
For example, a LCA of food would include water, fertilizer and fuel used in production; all energy used in processing and transportation; all packaging materials; energy used at the grocery store and the consumer’s home; and the impact of all waste generated. A LCA of a car would include all impacts of vehicle manufacture, operation and final disposal.
LCAs are mostly conducted for products, but they can also be calculated for processes and services. For example, the full impact of a Google search extends far beyond our computer to wires and distant banks of servers. The full impact of a cell phone call or text includes a share of the significant amount of energy used by cell towers.
Why LCAs matter
LCAs are important because they provide an unbiased, complete picture as opposed to just an isolated snapshot. And a proper LCA often reveals a reality that’s very different from what we might guess from just a casual glance.
For example, biofuels – particularly corn-based ethanol and palm-based biodiesel – are often heralded as the eco-friendly fuels of the future. But under scrutiny of a full LCA (factoring in deforestation or other land use changes; fossil fuel to run machinery and equipment; fertilizer; irrigation; and more), they often turn out to be not much better than the fossil fuels they’re replacing. In some cases, they’re actually worse.
It’s well documented that electric vehicles have a larger manufacturing footprint than conventional vehicles – but under scrutiny of a full LCA, they actually rank far better than conventional vehicles. Why? Because the vast majority of a vehicle’s environmental impact happens not in manufacturing or disposal, but in its use – and electric vehicles are far more efficient.
Similarly, efficient buildings, from the smallest home to the largest commercial complex, cost a bit more to build. But a LCA reveals that the extra cost of highly efficient windows, extra insulation and better air sealing is more than returned, in both dollar and emission savings, over a building’s lifetime. Efficiency isn’t an expense, it’s an investment that yields dividends.
And LCAs matter for food. Several years ago, Walmart discovered to its surprise that most of the emissions footprint of its food products didn’t come from packaging or transportation; it came from the on-farm use of nitrogen fertilizer. According to researchers at the Dalhousie University Agricultural Campus, 30 to 70 per cent the carbon footprint of most food is generated on the farm, much of that from fertilizers. Transportation accounts for only 11 per cent on average.
The bottom line
As the organic food example above demonstrates, life cycle assessment can get complicated.
But take heart: you don’t need to be an expert. You can go a long way by simply understanding why a complete picture is much more important than a snapshot, and then striving to incorporate that understanding into your thinking, actions and purchases.
(And you’ve probably already figured out that food that is as organic as possible, as local as possible and as minimally packaged as possible will fare best in any life cycle assessment.)