Climate change policy must be grounded in sound biodiversity science

Our failure to either stabilise the climate (e.g. IPCC Special Report - Sept 2018) or slow biodiversity loss (e.g. WWF Living Planet Report - Oct 2018) in many ways reflects the fact that these issues are treated separately. In reality, biodiversity loss—especially through deforestation—is a major driver of climate change, while climate change increasingly exacerbates biodiversity loss.

In recognition of this, many are now advocating that we work with natural ecosystems to address climate change. These so-called nature-based solutions (or natural climate solutions) received much attention at the United Nations biodiversity conference last week, and are again in the limelight at the UN climate change conference this week. They are even starting to make it into mainstream media (e.g. BBC).

However, it is extremely concerning that pledges for “nature” in climate policy often translate into targets for afforestation (tree planting). This is in large part because most modelled pathways that achieve the goals of the Paris Agreement assume massive scaling up of afforestation for greenhouse gas removal. Unfortunately, this encourages monoculture plantations of fast-growing exotic species (often in naturally treeless habitats rich in biodiversity, carbon and more resilient to climate change).  While these plantations store carbon in the short-term, their capacity to do so longterm is impaired by changing conditions and disturbances that are becoming more severe under climate change. 

To reliably provide services to people, including carbon storage, ecosystems must be able to resist, recover and/or adapt to change. A growing body of ecosystem science informs us that such resilience is, in turn, determined by connectivity, heterogeneity and diversity at multiple trophic levels. For example, recent experimental studies demonstrate that compared to monocultures, diverse plantations of tropical forest are more resilient to extreme floods and droughts, while mixed species forests are more resistant to pests and disease. Connectivity, meanwhile, is widely viewed as being critical to the adaptive capacity and integrity of intact forests and their biota in the face of environmental change.

It is essential that biodiversity scientists ensure their knowledge of ecosystem resilience better informs target-setting in climate policy. Otherwise, we will neither stabilise the climate nor protect nature at scale. We will only make things worse. 

[For a more detailed discussion see: Seddon et al (2018)]

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Essential resources

Hutchinson, C. et al. Scientific Reports 8:15443 (2018)

IPCC Special Report. World Meteorological Organization, Geneva, Switzerland (2018)

Jactel, H. et al. Curr. For. Rep. 3, 223-243 (2017).

Nature-based Solutions Policy Platform: www.nbspolicyplatform.org

Oliver, T. H. et al. Trends Ecol Evol 30, 673-684 (2015).

Sakschewski, B. et al. Nature Climate Change 6, 1032 (2016).

Watson, J. E. M. et al. Nat. Ecol. Evol 2, 599–610 (2018).