(a) Values for 2006 are based on actual use; values for scenarios H1 and H2 are based on estimated 2050 world energy and water use (Nakicenovic and Swart 2000; Barth et al., this volume).

(a) Values for 2006 are based on actual use; values for scenarios H1 and H2 are based on estimated 2050 world energy and water use (Nakicenovic and Swart 2000; Barth et al., this volume).

Cu production represented 0.03% of world water use, whereas under the future scenarios, they would represent 0.03-0.8% (based on 2050 world water use).

It should be noted, however, that these scenarios are only for copper. If the analysis scales for other major metals, the energy required to produce metals could approach 40% of global energy supply be 2050. This is clearly not possible given other demands for energy, and suggests that technology must find ways to provide services with much lower in-use metal requirements, or quality of life, as measured by service provisioning will decrease markedly.

In the future, it may be possible to rely much more heavily on renewable sources of energy. Even a steep increase in water use is unlikely to impact the global anthropogenic water budget, but local water shortages that affect mining (e.g., as in parts of Western Australia) may be expected to intensify due to population increase and climate change. In addition, access to land for exploration and mining and impacts of mining on land are also expected to grow. A decline in Cu ore grade from the current level of 0.8% to 0.1% would cause an eightfold increase in tailings per ton of Cu produced.

We examined whether physical availability may be a constraining factor for mineral commodities and, in particular, the limitations imposed by energy, water, and land requirements. Despite the simplifications of the model, the results indicate that particularly energy, as well water and land issues, could become increasingly constraining factors for metal production.

Research Agenda

From a research point of view, it is vital to quantify those aspects of consumption that are most intensive in minerals, including housing, household appliances, transportation equipment, and public and private infrastructure. Some scenario alternatives include higher-density living (e.g., in cities vs. suburbs), purchase of appliance services rather than appliances, and sharing of durable goods. Infrastructure, in part, reflects transport options, such as extensive road systems and private cars versus dense coverage by public transport. Some of the technological options and associated challenges have been discussed in earlier sections, and the rough calculations suggest the importance of a focus on energy use and energy sources.

Modeling and Data Priorities

Given that the challenges come from many directions, a model that represents these interactions is indispensable. Effective modeling, that is both theoretically sound and empirically rich, involves three components: a mathematical formalism, systematically compiled and documented databases, and, of course, content expertise—in this case, that of specialists in minerals and product life cycles. Typically, these three kinds of activities are conducted by three different research communities with less than perfect communication among them and tension between the different approaches. Our conviction is that collaboration across these boundaries is absolutely essential if we are to deepen our understanding of the present situation and to derive realistic and effective scenarios about how the present might be restructured for the future.

One compelling modeling requirement is to move from static models— whether MFA, LCA, IO, or others—to dynamic models that specify stocks as well as flows and the interrelationships among them, to capture the complexity of interconnected materials in consumer products. Considerable progress has been made in this regard. However, in combination with these primarily technology- and economics-based models, approaches are needed (such as scenarios) that are able to capture societal behavioral aspects, policies, and disruptive technologies (i.e., innovations that improve products/services in ways that the market does not expect). Significant conceptual and data gaps remain between existing models and databases and those that are needed for modeling the kinds of scenarios capable of meeting the magnitude of the challenges.

Another evident requirement for scenario analysis is the development of databases that make progress toward quantifying worldwide mineral stocks, including estimates of primary, secondary, and tertiary stocks, as well as associated flows by region. Flows are limited not only by resource availability but also by the infrastructure in place to exploit it, and this part of the capital stock is particularly in need of characterization and measurement. A major research project in progress will construct a global environmentally extended IO database with an unprecedented amount of detail on resource flows and some estimates of resource and capital stocks; however, this effort also highlights the difficulties of moving from a focus on flows to a comparable effort on stocks (Tukker et al. 2009).

It is vital to identify the technological options, existing or in development, that could be utilized at each stage in the mineral life cycle and estimate associated energy, water (and water quality), and land requirements as well as discharges of contaminants and waste associated with each.

In designing and developing the scenarios, dynamic models, and extended databases, researchers with expertise in the minerals sector will need to collaborate with colleagues from many other fields. Beyond the challenges just mentioned, the interrelationships between minerals and all other sectors of the economy must be captured within these models. Thus, a new depth of cross-disciplinary collaboration will be needed to take on the three main components of sustainability—economic, environmental, and social—as well as alternative institutional requirements. All of the modeling approaches discussed in this chapter make important contributions and are essential to address the tough issues of sustainability. In the long term, we expect that these approaches will converge.

Education and Research

To meet the challenge surrounding the sustainable use of resources, improvements are needed in many areas: technological innovation across the entire mineral life cycle (e.g., improvements in exploration, mining, and processing methods, product design and recycling system design), new policy instruments, more complete databases, more integrated models, better-informed stakeholders and citizen iniatives, and various types of entrepreneurship. Most importantly, the challenge of sustainability requires a generation of practitioners and analysts with a multidisciplinary understanding of a broad set of issues. This reality provides an exciting research opportunity for graduate students and experienced researchers alike, who will often need to work in teams comprised of individuals trained in the fundamentals of economics, engineering, geology, ecology, and mathematical modeling (to name but a few key fields), as well as policy formulation and implementation. All must be prepared and able to collaborate in the true sense of the word across disciplinary lines.


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