By Paul Locke, Craig Clifton and Seth Westra
Flooding is part of the natural cycle of climate variability, so current discussions about whether the recent floods in Queensland, Australia, or the record-breaking drought that preceded them, were caused by climate change, unnecessarily diverts attention away from the urgent need to adapt to climate extremes.
The best available scientific information indicates that climate change may amplify some aspects of natural climate variability, resulting in the normalization of weather events currently considered extreme. There is a growing body of empirical evidence (especially extreme temperatures, rainfall and sea levels) suggesting that climate change is already having this effect.
To date, the mining industry’s focus with respect to climate change has been on the emissions mitigation and the implications of a price on carbon. Recent events highlight the flip-side of the climate debate—climate adaptation. Mining operations may be more vulnerable to climatic extremes than previously assumed. As such, the mining industry needs to consider whether current approaches to mine and infrastructure planning and design provide an adequate basis for cost-effectively managing the extreme weather events that might occur in the future. Mining industry recognition of climate change has not yet translated into widespread consideration of climate change in planning and projects.
Planning and design are generally informed by design standards based on historical experience. However, our understanding of climate change suggests history will provide an increasingly unreliable guide to future experiences of climate and weather extremes. Unfortunately, since the scientific basis for extreme weather event projection under climate change is still emerging, there is no agreed alternative to the conventional approach.
In the meantime, approaches to planning and design are required that provide a sound basis for decision making under uncertainty and enable the identification of cost effective measures to enhance resilience. Risk techniques provide a useful framework, and should draw on analyses of climate extremes and their impacts and how they might be affected by climate change.
What is Climate Risk?
Climate risk refers to the extent to which an organization’s infrastructure, operations and markets are affected by variability and long term shifts in the averages and extremes of climate. In mining operations, climate risk may be manifested in areas as diverse as:
• Threats to mine water supply security;
• Damage to mines and associated transport infrastructure from flooding, cyclones and bushfires;
• Threats to port operations and infrastructure from sea level rise and storm surges;
• Overtopping of tailings dams, leading to failure and environmental contamination;
• Delays in construction of mine infrastructure or in production and shipping of product;
• Human health threats for mine staff from changes in working conditions or disease prevalence;
• Climate-related social dislocation and security concerns in communities around mining operations;
• Changes in surface water and groundwater interactions, with implications for acid mine drainage or movement of contaminants; and
• Threats to vulnerable ecosystems in areas within mining operations from direct climate impacts or via climate sensitive agents such as fire, pests, weeds or diseases.
The effects of climate risks might include: operational delays, revenue losses, increased production costs, labor shortages, environmental damage, loss of reputation and adverse mine legacies. If properly understood and managed at the right time in the mine life cycle, these risks can be accounted for in planning, investment and operational decisions.
Assessing Climate Risk
The sources of climate risk, its importance and management responses vary with the phase of a mine’s life cycle. For example, when developing a construction program for a mine site or transport infrastructure it would be useful to know the projected number of rain days or the likelihood of flooding over the coming wet season. By contrast, a long-term water supply strategy could involve establishing water security from a number of supply sources over the mine’s design life. Such an analysis would need to include an evaluation of the influence of natural climate modes, as well as longer term climate change projections. Finally, a mine rehabilitation strategy is concerned with the likely climate beyond the end of the mine design life, and therefore would need to consider long-term climate change projections.
The diagram, on page 58, provides an overview of the techniques available for characterizing climate risk at each of these time scales.
Incorporating Climate Knowledge into Mine Management
The assessment of risks and opportunities associated with climate variability and change should be an integral part of all mining projects from the initial planning all the way through to mine decommissioning. This assessment could simply consist of asking some questions to assess risk and vulnerability as part of the design scoping discussion, or it could be a more specific and comprehensive plan tailored to specific aspects of a project.
The fundamental question is how does climate variability and change affect the mining project? This involves an assessment of:
• The project’s sensitivity to climate: this refers to the degree in which change in climate will affect the project. For example, what would be the effect of a 20% increase in flooding from a nearby river or a decrease of inflows to mine water storage of 20%?
• The project’s exposure to climate: this refers to the magnitude of natural variability and/or extent of projected humaninduced changes in temperature, water availability, likelihood of floods and storms, and/or sea levels.
• The capacity to adapt to change: the capacity—planned or unplanned—of the mine operator, local communities and/or natural environment to adapt to change in climate.
Considering Climate Change at Each Step of the Project Life Cycle
An alternative framework for assessing and managing risk considers the likely climate impacts at all stages of the project life cycle (above). This will involve asking additional questions to what is normally considered, with the aim of embedding an appreciation of climate risk and opportunity in project vision, goals and delivery methods.
Climate variability and change contain risks and opportunities that will manifest at all stages of the mine lifecycle, at a range of geographic locations and over a range of planning horizons. This requires a robust understanding of how the climate currently operates and of how this might change in the future. It also requires an understanding of the design and operational flexibility to manage this risk. Although uncertainty will always be part of any assessment or risk, the tools are now available to assess and adapt to climate risk throughout the mine life cycle.
Paul Locke is a senior climate change consultant for SKM; Craig Clifton is climate change practice leader for SKM; and Seth Westra is a senior research associate at the University of New South Wales Water Research Center. Reprinted with permission from Sinclair Knight Merz Pty. Ltd.
Recovering from Extreme Weather: Two Steps Forward, One Step Back?
Coal export data confirm that the Queensland coal industry—which has borne the impact of record-breaking rainfall in recent months—is operating at around two-thirds of its capacity, compared with 12 months ago.
Queensland Resources Council Chief Executive Michael Roche said recently that in February 2011, Queensland exported 8 million metric tons (mt) of coal compared with 12 million mt in February 2010.
“This is only one month’s worth of exports, but the numbers are consistent with company reports and the QRC’s own estimates of a 30 million mt downturn in coal production in 2010-11 caused by wet season floods,” Roche said. “Three out of four coal mines are still working to remove water from their properties under special environmental discharge approvals from the state government.
“These special discharge approvals are of limited benefit without the right rainfall pattern, and there is now growing concern over the outlook for continuing rain in the coal regions and possible formation of another tropical cyclone. What can be pumped off a site can be replaced just as quickly by such rainfall, and your flooded coal pit is then right back to square one of the business recovery phase.”
The QRC and independent consultants have forecast coal production losses of at least A$5 billion this financial year, with resulting lost royalties of A$400 million.
- Written by E&MJ News
By Paul Locke, Craig Clifton and Seth Westra