Climate Change is especially a water change. The temperature rise will bring increases in water demand in a world with higher population. According to the IPCC assessments, some regions of the world must expect an increment of precipitations, whilst other regions might face a reforcement of drought conditions.
Rainfall variability, which has been higher in the last years, will increase the risks of both water shortages and flooding.
The global circulation models (GCMs) estimate the fluxes of energy, mass and momentum between the Earth´s surface and the atmosphere; considering several gas emission scenarios and other data such as land use etc. GCM outputs need to be downscaled for specific applications.
There are several GCMs, emission scenarios and downscaling techniques. In Zeta Amaltea we consider the data from the EU proposal ENSEMBLES.On the other hand, stochastic realisations of climate variability can be obtained from weather generators, which feed physically-based soil-water models, combined to hydrological models, to assess the impact of climate change and climate variability on water resources in a catchment or zone.
This combination and integration of techniques is the most updated approach to assess climate impact on water resources.
Besides the modelling-based assessments of climate impacts on water resources, considering the most updated GCM results, downscaling techniques, weather generators and models, we can also conduct bottom-up evaluations to identify local risks of current water management.
We use the tools provided by the Water Footprint Network to estimate the total volume of freshwater needed to produce specific goods and services, being aware as well of the efforts to release the ISO 14046 procedures. We consider also the Life Cycle initiative approach.
Furthermore, we apply the WBCSD Global Water Tool to map water use by businesses and institutions, assessing the risks relative to their global operations and supply chains. All these tools provide the insight of our bottom-up assessment regarding current water management by business or institution, pointing out their specific vulnerabilities. The specific tool to be used depends on the particularities of the target institution and the general goal to be met.
We conduct both activities: A risk assessment, combining top-down and bottom-up approaches, as well as risk management recommendations, following the ISO 31000 guidelines.
Our work is based on the EU White Paper on adapting to Climate Change and publications of the European Environmental Agency about climate impacts on water resources. We consider the European Climate Adaptation Platform (Climate-ADAPT) resources.
We also follow the World Bank recommendations about Climate-smart decisions, as well as the OCDE recently-released policies to deal with climate-change water vulnerabilities using a risk-based approach.