Could a stable future climate reverse summer rainfall decline for Europe?
Climate researchers outline how summer rainfall decline across Europe could be partially reversed if global temperatures stabilise, in a new study led by the National Centre for Atmospheric Science.
Global warming is causing Europe to experience milder and wetter winters, along with hotter and drier summers.
Assuming that no drastic greenhouse gas emission reductions are implemented in the coming years, the planet is expected to overshoot 1.5°C global warming by the mid-2030s – in around 12 years from now. And during that time, summer rainfall in Europe is projected to decrease even further.
This study has important implications for climate change adaptation and planning decisions.
In particular, the prospect of halting an ongoing summer rainfall decline would have important implications for water resources management in climate change ‘hotspots’ such as the Mediterranean.
Researchers are attempting to understand what a rapidly changing climate will mean for our future, to help inform climate adaptation plans. An important part of this is picturing a net zero emissions world, where greenhouse gas emissions are no longer rising and global temperatures have stabilised.
A team of climate scientists have been operating a complex computer model – the UK Earth System Model (UKESM) – to simulate the Earth’s conditions in coming years. To investigate how a stabilising climate differs from a rapidly warming one, they have developed simulations of the climate that are using constant concentrations of greenhouse gases.
In a study published today, researchers have analysed rainfall projections from six model experiments that span a range of global warming levels between 1.5°C and 5°C and for the next 500 years. All of the experiments had fixed atmospheric concentrations of greenhouse gases.
The study found that in many European regions, the summer rainfall decline caused by global warming may be reversible to some extent if global temperatures stabilise. But, this rainfall recovery would be slow – over hundreds of years.
Reversing rainfall decline, in a net zero emissions world, may have links with larger-scale change in the atmosphere and in our ocean environments. Changes in the Atlantic sea surface temperature, Atlantic Meridional Overturning Circulation, humidity, and atmospheric circulation could all contribute.