Computer models show economic and social impacts of climate change

Professor Jakeman was in Brno at the ISESS 2011 Conference. His keynote speech was about making progress in environmental modelling and simulation.
In Australia, long term drought has had a huge impact on its river and groundwater systems and the system of agriculture.We have experienced variable weather conditions for centuries, some places more than others. But there is evidence that the longer term climate is changing today. Temperatures look to be rising and many parts of the planet are subject to long periods of extreme drought and, at other times or in other places, extensive flooding. These variations can have enormous ecological and socioeconomic consequences.

Professor Jakeman was awarded the Silver Medal of Masaryk University. Foto: David Povolný.
Professor Jakeman was awarded the Silver Medal of Masaryk University. Foto: David Povolný.

In Australia, long term drought has had a huge impact on its river and groundwater systems and the system of agriculture. The Australian Government has responded to its water resource problems by legislating significant water reforms through its National Water Initiative process. To help implement these reforms the Government is building its scientific knowledge, databases and models so that it can manage and plan on how to share water between the environment and other uses like agriculture.

One important aspect of this is a national Groundwater Action Plan, part of which was the setting up in 2009 of the National Centre for Groundwater Research and Training. In this Centre it is the role of Anthony Jakeman, from the Australian National University in Canberra, to lead a program that integrates socioeconomics, policy and decision support to help develop the science for an understanding of and adapting to the impacts of climate, policy and other drivers on the health of catchments and their communities. We met Professor Jakeman in Brno, CZ, at the ISESS 2011 Conference after his keynote speech and just a few minutes after he was awarded the Silver Medal of Masaryk University.

What are the major water problems in Australia?
In simple terms it is one of not enough water to go around for the ways we irrigate presently and not enough for the health of the aquatic environment and sustaining our groundwater systems. In addition to this, groundwater levels are going down because of too much extraction in many places. In hindsight, it is unfortunate that farmers were encouraged to expand irrigation during decades when rainfall was more plentiful. We built dams for irrigation and a lot of associated infrastructure. Now we are trying to implement policies that allocate water first to the environment and then to be shared for other uses.

How does modelling offer solutions about how to cope with extreme drought?
The role of modelling is as much one of working with interest groups as it is of performing the technical aspects of building the models. As modellers we must work with landholders, irrigation groups, local governments and catchment management agencies, and higher-level policy advisors, that is, not just disciplinary experts in ecology, hydrology, economics and social sciences. This relationship involves defining with them the problems to be modelled.  We also select the indicators to be used to assess, through technical modelling, how we can improve things. This critical relationship is also about eliciting everyone’s knowledge, debating it, sharing it and integrating it into the modelling process. In this way we try to work with the best information we can get, identify gaps in it, and build trust with interest groups.

Is this an unusual role for modelling, which, I gather, viewed historically has been very technical?
Historically yes, but participatory modelling is becoming more commonplace in complex situations where there is no right answer. Ideally the modelling team becomes a knowledge broker. This is my long-term aim – that is, where some members of the environmental modelling team are seen as objective participants in a wider community process that leads to adoption of the best strategies overall to adapt to problems like climate change..

One of your fields of interest is hydrology. Where does that fit in your modelling process?
Hydrology is an integrator through any catchment system being studied. Climate and in particular droughts and floods affect the entire water system. We must model the water flows through the entire system from headwaters down, sometimes as far as the sea. And on the way we must model the extractions and other losses of water, and very importantly the interactions with groundwater. We need to know all this using hydrological models so we can see how much water is available to downstream users and to use it to assess the effects on the ecosystems in rivers, their floodplains and wetlands.

Which economic, social and environmental impacts of climate change does your modelling show?
It shows many things. It can show how the economics of farmers are being affected in the current situation, and what is happening to the ecology in an indicative way. It can explore how adaptations like new technology, clever planting and timing, and policy innovations by government affect these as well. Of course modelling carries with it many uncertainties about what it predicts. The trick is to manage this uncertainty so that we can make comparative judgments about the differences between a number of strategies.

You have collected large amounts of data about the system. Do you also take into account the situation of individual farmers?
Yes, our teams have a strong social component to do this. The role of people in this component is not only to help assess the social impacts of change but also to understand how landholders behave and might behave under new conditions. That is, we need to understand the capacity of different farmer groupings to adapt to change so we can incorporate that in our model.