CIRCULAR CHALLENGES TITEL
Circularity is often simplified to reduce-reuse-recycle, but what are the challenges while looking at the big picture on planetary level? Planetary boundaries and definitions Huesemann & Huesemann define three indicators for circularity on planetary level: - All energy comes from renewable sources at or below renewable rates. - All materials come from renewable sources at or below renewable rates. - Waste can only be released at or below assimilation rate, without negative impacts for the ecosystem of biodiversity.
needs to grow at unprecedented annual rates for 17 metals in the next 30 years to bring about the Paris energy transition, while this does not even take into account the metal use by other industries. This is also a geopolitical problem, as Europe has almost no relevant mining and refining capacity of its own. Metal production is particularly damaging. The Environmental Cost Indicator shows that the “shadow costs” of, for example, one kilogram of aluminium or one kilogram of steel are roughly 1000 times and 100 times higher than those of one kilogram of concrete. The ECI is based on Life Cycle Analysis with 11 monetized environmental impact categories.
Contours of a New Decade
The aim of circularity is to keep impacts within planetary boundaries, and moreover avoid depletion of needed resources. We are currently far removed from that point as we overshoot particularly the safe boundaries for biodiversity loss,deforestation,nitrogen and phosphate depositions and global warming, causing substantial alteration of the Earth System.
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“Rate” is the keyword in the Huesemann indicators. Overshooting is temporarily possible, but only at the cost of damage, destruction and depletion. Restoration is sometimes possible, but not all processes are reversible, or not in a linear manner. Then if this is our global compass, where do we meet problems, what are the circular challenges? Challenge 1: Renewable energy and nonrenewable materials One problem is that we are moving towards renewable energy, but in doing so we rely on nonrenewable materials, particularly a wide array of (rare) metals for solar, wind and batteries. Various reports signal that mining production
Figure 1 The Environmental Costs (or shadow costs) for common construction materials (image credit: TNO, 2018a), based on Life Cycle Analysis of 11 monetised environmental impacts. Reuse and recycling can help to reduce the demand for virgin metals, but only in the long term, while we need the renewable energy transition now. Reuse and recycling do not allow volume growth, while the global demand is far exceeding the global supply. Substitution of rare materials in solar, wind and batteries would help, but without shifting to other materials that will quickly be depleted.
