How much impact has climate change on contaminated land and pollutants?
How much impact has climate change on contaminated land and pollutants is an excellent question with a blank answer currently. The impact of climate change factors on the risk assessment, design of future remediation systems and management of current and future contaminated sites will be likely a key point that we should take into account or consider.
On the one hand, sustainability indicators in terms of environmental, economic and social are the basis for the sustainable remediation assessment of contaminated soils and groundwater. In this way, the UK Sustainable Remediation Forum (SuRF-UK) has developed a framework for assessing their sustainability, and for incorporating sustainable development criteria in land contamination management strategies, setting up in this sense a series of sustainability indicators for their remediation. These indicators are indicative of the range of issues that may be relevant, and are provided to help assessors identify the most critical issues to evaluate further in a project. As well, they highlight which are the challenges at global, national or local level.
On the other hand, in readiness for our future climate and its changes, there is a need to evaluate the risks of climate change and to predict how it is going to affect our future. In this way, some European projects have tried to give a response since 2000. PRUDENCE, Prediction of Regional scenarios and Uncertainties for Defining EuropeaN Climate change risks and Effects, was a European scale investigation project which aimed to quantify the confidence and the uncertainties in predictions of future climate and its impacts, using an array of climate models and impact models and expert judgement on their performance. Continuing the theme of this investigation, the project ENSEMBLES was carried out, based on Predictions of Climate Changes and their Impacts. This project aimed to build a common ensemble climate forecast system which would be developed for use across a range of timescales (seasonal, decadal and longer) and spatial scales (global, regional and local). So, this model system would be used to construct integrated scenarios of future climate change, including both non-intervention and stabilisation scenarios. ENSEMBLES ended in 2009 and immediately a new major project was started up, CORDEX, COordinated Regional climate Downscaling Experiment, which is an international project to produce an improved generation of regional climate change projections world-wide for input into impact and adaptation studies.
All this effort provides us a quantitative risk assessment of climate change and climate variability. On this basis, the next step would be to quantify the impact of climate change on contaminated land and to examine technical evidence of this impact and potential technical adaptation strategies that should be followed.
Although, all projects identified in this document have done extremely respectable and useful work, there is currently very little published work providing experimental evidence of potential direct impacts of climate change on contaminated land and remediation systems. The closest work is that which investigates and compares the impacts of different climatic regions on biological and chemical properties of contaminated soils and contaminant behaviour. Consequently there is a need for effort in this area to ensure that remediation choices being made now are the right ones by future land use, climatic conditions and societal demographics.
So, in the United Kingdom, in 2007, a multi-institutional and multi-disciplinary research consortium was involved in a project called SUBR:IM, Sustainable Urban Brownfield Regeneration: Integrated Management, whose aim was producing integrated and sustainable solutions for the development of brownfield land in urban areas. They concluded that from the evidence available in the literature and collected as part of the study, it is clear that certain climate change scenarios are expected to have significant impacts on current and future contaminated land and remediation systems. These impacts will have major effects on the future management of contaminated and remediated sites and are expected to influence the way risk is managed on those sites and the design of future remediation strategies.
However, this project is only the beginning of an emerging area of research. We still have a long way to go. It is important to set up a good correlation between the climate change and the current soil remediation technologies so that their implementation will not be a complete waste of time in the future when the environmental conditions change, in particular, those systems that required long time scales.