A changed climate represents a changed risk picture for society and industry. We have the tools for planning for the future – a future that is uncertain – we must simply start to use them…

This summer has given us a taste of the expected effects of future climate changes -  flooding, landslides and closed roads and railway lines due to the infrastructure not being able to cope with the new environmental conditions.

We need to improve the way in which we plan – especially when we are going to invest in infrastructure that is to last for several decades. However, the future is uncertain and what we have to plan for is far from clear. In such a setting, risk-based adaptation to climate changes will be an important tool.

In the current debate, it seems as if the interest in climate challenges has diminished and is being  overshadowed by more urgent problems, such as the financial crisis and unemployment. In the USA, climate change has become more or less a term of abuse and we see tendencies towards climate sceptics gaining ground in Europe too. However, it is quite certain that the climate is changing and it is overwhelmingly probable that the changes are caused by human activity. Unfortunately, the climate processes have probably come so far that we can hardly avoid a change in the global average temperature and thus subsequent changes in weather patterns. We must thus be prepared for new, changed environmental strains on infrastructure in the decades to come.

When planning for several decades into the future, we must admit there is a great deal of uncertainty about what the future will hold – both globally and locally. We are actually facing several layers of uncertainty:

• Climate-related uncertainties: what will the future greenhouse-gas concentrations be in the atmosphere – and will other climate drivers change? At a local level, it is uncertain how local variations and physical factors will affect future weather patterns. The global climate models are not sufficiently advanced that they can predict what will happen in a little coastal town or local valley.
• Uncertainty regarding the effect on existing and planned infrastructure. Might we experience new damage mechanisms, how will older facilities be able to cope with changed strains and how can different types of infrastructure influence the course of events in extreme weather situations?
• Uncertainty linked to how we can develop and implement measures to adapt society to the expected effects of the future climate. This is not least dependent on economic growth, financial strength, budgets, population growth, new technology, etc.

Based on the uncertain picture that has been outlined, the most efficient way of adapting to climate is to adopt a risk-based approach to the problem. We are facing a decision-making problem which requires us to deal systematically with the uncertainties ahead of us and requires the various scenarios to be weighed up against each other. Such an approach to decision-making problems has been developed over the past 40 years and has become completely normal in sectors where the consequences of making the wrong decision can be disastrous.

However, there is one challenge which we must take into account. In normal risk-based approaches, the risk analyst will want to base his or her assessments on historical experience, and the more information there is from stable systems, the more accurate the predictions about the future. This is a challenge when planning for a climate that is changing. Weather forecasts are becoming more and more outdated as the climate changes, and may lead to us underestimating the future risks facing vulnerable infrastructure which we want to function for several decades to come.  Studies of, for instance, the expected frequency of storms in New York have shown that the official statistics, which on the whole are not adjusted to take account of climate changes, very probably underestimate the number of future storms over the city.

If there are so many uncertainties about the future, many people may ask whether it is possible to plan for anything with any degree of certainty. In my opinion, we can do so by using a planning strategy based on risk assessments of various scenarios and introducing a higher level of flexibility when executing and following up the plans. We need to add a monitoring element to the risk analysis and plans so that we can identify how the climate effects change in local areas. The information we obtain from this monitoring work must be used to adjust the plans when we see that the climate changes’ effect on the weather deviates from our original assumptions.

A changed climate represents a changed risk picture for society and industry. We have the tools for planning for the future – a future that is uncertain – we must simply start to use them. Risk-based climate adaptation and flexible plans which allow an opportunity for revision as we gain experience about how the climate affects the local weather in various regions should be a natural element of future investment projects, whether owned by the authorities or industry.