FIRST RESULTS OF CLIMATE SCENARIOS IN RESCCUE

The future climate is estimated by using model projections under several emission scenarios, known as Representative Concentration Pathways (RCPs), according to the most current IPCC (Intergovernmental Panel on Climate Change) report. Climate models use dynamical equations to simulate the natural variability and possible climatic changes. Thanks to downscaling methods, it is possible to project the future climate at local scale, facilitating thus the evaluation of climate change impacts in urban services.

In the RESCCUE project context, climate changes in Barcelona, Lisbon and Bristol are analysed. The first results show changes in the average of some climate variables, with temperature increase being probably the most important. By the end of the century, annual mean temperature could rise more than 2°C in the three cities. The worst scenarios (which correspond to the pathway RCP8.5) project a maximum warming up to 6°C in Barcelona and 5.5°C in Lisbon and Bristol.

Rainfall amounts could experience a significant increase between 5% and 40% in Bristol by 2100 under the RCP8.5 scenario. Lisbon would experience a possible decrease in annual rainfall down to -15% for the 2016-2035 period. Projections for Barcelona show no significant changes in rainfall, but with a high uncertainty level. However, an increment (up to +20%) of the potential evapotranspiration would cause a greater water stress. Moreover, the snowfalls could decrease between 50% and 100% by the end of century in Barcelona and Bristol. This would cause an important reduction of the water reserves.

Finally, the mean sea level could rise up to 50 cm in Lisbon and 60 cm in Bristol by 2100 under the RCP8.5, but with a high uncertainty level. In Barcelona, the uncertainty level is greater and the most probable scenario shows no significant changes in sea level.

The RESCCUE Work Package 1 is now working to provide projections of climatic extremes by April 2018. In the next climate post, we will talk about changes in extreme rainfall, temperature, wind, wave height and storm surge.