Planting 20% more trees throughout Europe could help climate change, boost ...

Planting 20 percent more trees throughout Europe would not only help stave off the effects of climate change, but it would boost the continent's rainfall too, a new study suggests.

The research points out that changes to land cover - by adding forests - can have a 'substantial' impact on the dry conditions that are associated with changing weather patterns, while also changing rainfall patterns by an average of 7.6 percent in the summer.

'We conclude that land-cover-induced alterations of precipitation should be considered when developing land-management strategies for climate change adaptation and mitigation,' the authors wrote in the study.

Trees store carbon and an increase of this magnitude on the continent could remove a significant portion of the nearly 43 billion tons of carbon dioxide that humans emit annually, according to 2019 data.

'Forestation-induced precipitation changes appear to be subject to spatial trade-offs due to downwind effects,' the authors added. 

'While we find a local increase in precipitation due to forestation across Europe, forestation might reduce precipitation further downwind in winter. However, forestation increases precipitation downwind in summer, probably due to higher moisture supply by forests than by [agricultural land].'

They continued: 'Overall, our results highlight that [land-cover changes], such as forestation, can considerably alter precipitation in the mid-latitudes, both locally and further downwind. Hence, the consequences of human land use for water availability should be considered alongside biogeochemical effects and the biogeophysical alteration of temperatures.

'As droughts are projected to become more severe with changing climate in Europe, the interplay between [land-cover] and water availability deserves more attention.'

The researchers acknowledge that not every European country can realistically increase its forest land by 20 percent, pointing out some countries are better suited than others.

As such, the researchers looked at the potential according to the Global Reforestation Map and found that 14.4 percent of land surface is suitable for forestation, specifically in the British Isles, western and southern France, Portugal, Italy and Eastern Europe.

The researchers are not yet certain why planting more trees would increase rainfall, but it could be due to the way they interact with cloudy air, according to the BBC.

One of the study's co-authors, Ronny Meier from ETH Zurich, said areas like the Mediterranean need an increase in tree population the most.

'Probably the most threatening climate change signal that we expect in relation to precipitation, is this decrease in summer precipitation that is expected in the southern parts of Europe like the Mediterranean,' he told BBC News.

'And there, according to our study, forestation would lead to an increase in precipitation. So the forestation would probably be very beneficial in terms of adapting to the adverse effects of climate change.'