Why efficiency is not enough

Figure 1. Resources Needed to Support Global GDP (source: Paul Gilding, The Great Disruption)

Advancing sustainable consumption will require a mix of approaches that address the “upstream” impacts of production as well as the choices made by consumers. “Greening” products by achieving more efficient use of energy and material inputs is important but evidence suggests that greater efficiency alone will not be sufficient to significantly lessen the resource impacts of our collective consumption.

For example, take the analysis coming from the field of ecological footprinting. As Figure 1 illustrates, global consumption in 2010 required over 150% or 1.5 times the Earth’s ability to provide renewable resources and absorb carbon pollution, creating a deficit in resource spending, or ecological overshoot, that will be increasingly hard to reverse. The red line shows how resource pressures will continue given standard assumptions of global economic and population growth. The green line reflects a slower rate of resource use when we include expected gains in efficiency. But even at that reduced level, we’ll need to consume over 3 times the Earth’s resources by the year 2050 in order to keep pace with expected growth in GDP. Figure 1 of course represents global conditions. In the US, our Ecological Footprint is already much higher than the global average - requiring more than 4 Earths if everyone in the world were to live like the average American.

Other sources tell a similar story. In 2008, the International Energy Agency projected that demand for materials will at least double by 2050 and that this demand growth exceeds the potential for industry gains in efficiency.

So why are technological improvements expected to fall short?

  • First, the magnitude of overshoot requires very large improvements and it’s very unlikely that technology (alone) can produce the needed reductions in impact.

  • Secondly, rebound effects cut into efficiency gains and may dampen or diminish any improvements. The rebound effect occurs when a consumer engages in a behavioral change that saves them money; the savings are then spent in other ways, with resulting environmental and economic impacts.

  • Finally, the benefits resulting from technological improvements can be overwhelmed by the scale of overall consumption. So while some products and services become greener, the sheer volume of global consumption outpaces any upstream improvements.

This is one reason why a true sustainability strategy must address both production and consumption. Addressing either by itself will be insufficient.