Trade-offs in using European forests to meet climate objectives

Abstract

The Paris Agreement advances forest management as one of the pathways to halt climate warming through carbon dioxide (CO 2 ) emission reduction 1 . The climate benefits from carbon sequestration from forest management may, however, be reinforced, counteracted, or even offset by concurrent management-induced changes in surface albedo, surface roughness, biogenic volatile organic compound emissions, transpiration, and sensible heat flux 2 – 4 . Forest management could, thus, offset CO 2 emissions without halting global temperature rise. It remains, therefore, to be confirmed that sustainable forest management portfolios for the end of the 21 st -century for Europe would comply with the Paris Agreement, i.e., reduce the growth rate of atmospheric CO 2 , reduce the radiative imbalance at the top of the atmosphere, and neither increase the near-surface air temperature nor decrease precipitation. Here we show that a spatially-optimized portfolio that maximises the carbon sink through carbon sequestration, wood use and product and energy substitution, reduces the growth rate of atmospheric CO 2 but does not meet any of the other criteria. The portfolios that maximise the carbon sink or forest albedo pass only one, albeit different, criterion. Managing the European forests with the objective to reduce near-surface air temperature, on the other hand, will also reduce the atmospheric CO 2 growth rate, thus meeting two out of four criteria. Our results demonstrate that if present-day forest cover is sustained, the additional climate benefits through forest management would be modest and local rather than global. Based on these findings we argue that if adaptation would require large-scale changes in species composition and silvicultural systems over Europe 5 , 6 , these changes could be implemented with little unintended climate effects.

Step back from the forest and step up to the Bonn Challenge: how a broad ecological perspective can promote successful landscape restoration

“…Clearing forests releases C stored in trees but it increases the Earth's albedo (reflection of solar radiation back into space) such that we now need scientific assessments of whether this leads to net cooling or warming. Luyssaert et al () assessed trade‐offs in using European forests to meet climate objectives, and found that improved C sequestration may be offset by changes in surface albedo, land surface roughness, VOC emissions, transpiration, and sensible heat flux induced by different forest management. Understanding the extent to which C sequestration through restoration within FLR can cool the planet will therefore depend on the net interplay of carbon uptake and VOC emissions, as well as albedo and transpiration differences between forest types and between different biomes.…”

“…Scientific research will play an essential role in focusing and delivering evidence‐based knowledge to back up this larger process (as seen by recent publications cautioning that storage carbon alone does not necessarily stop climate warming; e.g. Unger ; Luyssaert et al ).…”

Central Taiwan’s hydroclimate in response to land use/cover change

“…Land use/cover change (LUCC) can induce significant variations in land surface fluxes and water budget partitioning, thereby impacting local and regional climate [1][2][3][4][5][6][7]. The influences of LUCC in the Earth system have been a major concern for the global change assessment.…”

Spatial Pattern of Climate Change Effects on Lithuanian Forestry

“…Following the Paris Agreement [21], the European Union (EU) has committed to a 40% domestic reduction in greenhouse-gas emissions compared to 1990 levels by 2030, 25% of which is expected to come from land-use change and forestry [22]. Despite doubts about whether such efforts may have an influence on climate change mitigation [23], they will influence and already have influenced forest management decisions, and, thus, forests and forestry [24]. Forest management has long aimed for a sustainable yield of wood; however, the concept of sustainable forest management has been adjusted to also include ecological and social sustainability requirements [25].…”