What happens if population increases and food demand result in mass deforestation across an entire region? If whole forests disappeared, how would it impact climate, temperatures, and precipitation?
Researchers from the Norwegian University Science and Technology and the Justus-Liebig University Giessen in Germany tackled these questions by using a regional climate model to project the impacts that deforestation across Europe would have on temperature and local communities.
The researchers ran simulations on complete deforestation and what would happen if cropland in Europe were converted to forests.
Climate models are not without their limits, and often times global climate models underestimate the impacts of climate change at the regional levels which are much more extreme than the models account for.
The results were published in the journal Environmental Research Letters.
“We wanted to perform a quantitative analysis of how much land cover changes can affect local climate. Important transitions in the land use management sector are envisioned in near future, and we felt important to benchmark the temperature response to extreme land cover changes,” said Francesco Cherubini, the study’s first author.
Models that accurately assess the effects that environmental and climate changes will have on an area are crucial for implementing policies that curb emissions, manage and conserve vital resources, and combat global warming.
“Decisions regarding land uses are frequently taken at a subnational level by regional authorities, and regional projections of temperature and precipitation effects of land cover changes can help to maximize possible synergies of climate mitigation and adaptation policies, from the local to the global scale,” said Cherubini.
Land use is going to be an important part of the climate change conversation as projected increases in population will, in turn, increase the demand for food and cropland.
The researchers wanted to see how major changes in land use would affect Europe and to resolve contradictions found in past studies that show that deforestation could either cool surface temperature or cause an increase in hot, dry, summers.
After running their model to project the impacts of complete deforestation, the researchers discovered that it would create a slight cooling over the region, but would have bigger impacts at local levels.
The model showed that bare ground would decrease temperatures by .06 degrees Celsius overall, but in some areas, cooling could be as much one degree.
Even with the cooler temperatures in northern and eastern Europe, the models also showed an increase in temperatures in western and central Europe as well as more extreme summer seasons.
“Regional cooling from deforestation might look counter-intuitive, but it is the outcome of the interplay among many different physical processes,” said Bo Huang, a co-author of the study. “For example, trees tend to mask land surface and increase the amount of solar energy that is not reflected back to space but it is kept in the biosphere to warm the climate.”
Conversely, when the researchers used their model to show what would happen if cropland were converted to forests, it resulted in a warming trend over Europe by .15 Degrees Celsius with evergreen forests and .13 Degrees Celsius with deciduous forests.
This thought experiment in deforestation shows just how much local and regional areas are impacted by huge differences in climate and vegetation.
The researchers say that understanding how local communities will be impacted by changes in vegetation cover is important for land management policies.
“It is important to increase our knowledge of land-climate interactions, because many of our chances to achieve low-temperature stabilization targets are heavily dependent on how we manage our land resources,” said Cherubini. “We need more research to further validate and improve the resolution of regional climate change projections, since they are instrumental to the design and implement the best land management strategies in light of climate change mitigation or adaptation.”