Scenarios for future biodiversity loss due to multiple drivers reveal conflict between mitigating climate change and preserving biodiversity

Abstract

We assess the potential for future biodiversity loss due to three interacting factors: energy withdrawal from ecosystems due to biomass harvest, habitat loss due to land-use change, and climate change. We develop four scenarios to 2050 with different combinations of high or low agricultural efficiency and high or low meat diets, and use species-energy and species-area relationships to estimate their effects on biodiversity. In our scenarios, natural ecosystems are protected except when additional land is necessary to fulfil the increasing dietary demands of the global population. Biomass energy with carbon capture and storage (BECCS) is used as a means of carbon dioxide removal (CDR) from the atmosphere (and offsetting fossil fuel emissions). BECCS is based on waste biomass, with the addition of bio-energy crops only when already managed land is no longer needed for food production.Forecast biodiversity loss from natural biomes increases by more than a factor of five in going from high to low agricultural efficiency scenarios, due to destruction of productive habitats by the expansion of pasture. Biodiversity loss from energy withdrawal on managed land varies by a factor of two across the scenarios. Biodiversity loss due to climate change varies only modestly across the scenarios. Climate change is lowest in the 'low meat high efficiency' scenario, in which by 2050 around 660 million hectares of pasture are converted to biomass plantation that is used for BECCS. However, the resulting withdrawal of energy from managed ecosystems has a large negative impact on biodiversity. Although the effects of energy withdrawal and climate change on biodiversity cannot be directly compared, this suggests that using bio-energy to tackle climate change in order to limit biodiversity loss could instead have the opposite effect.

Trade‐offs for food production, nature conservation and climate limit the terrestrial carbon dioxide removal potential

“…We investigate the opportunities and trade-offs for BPs on agricultural and natural areas separately such that the results are additive. However, as in previous studies (Humpen€ oder et al, 2014;Lenton, 2010;Powell & Lenton, 2013;Smeets, Faaij, Lewandowski, & Turkenburg, 2007;van Vuuren et al, 2011), we first concentrate on the conversion of degraded (Oldemann, Hakkeling, Sombroek, & Batjes, 1991) or abandoned cropland and pastures before converting natural land to BP, in order to protect still existing natural ecosystems from further human interference through tCDR. The following paragraphs introduce the constraints and the underlying rationale in more detail.…”

“…Previous studies agree that land availability for tCDR is, among others, tightly linked to food demand and production efficiency, associated land management practices and ecosystem conservation: It will likely be a challenge to simultaneously meet the needs of food production for a growing world population, nature conservation and climate protection through avoided deforestation or BPs (Beringer, Lucht, & Schaphoff, ; Kraxner et al., ; Lenton, ). Most likely, only a shift towards highly efficient food production systems with low meat consumption would release sizable agricultural areas for tCDR without compromising forest protection and biodiversity conservation (Kraxner et al., ; Powell & Lenton, , ). Nevertheless, tCDR potentials—generally assumed to be climate‐beneficial – identified in these studies could increase if the emissions incurred the conversion of biomass to long‐lived carbon products were reduced through technological improvements (Lenton, ).…”

Historical Environment Is Reflected in Modern Population Genetics and Biogeography of an Island Endemic Lizard (Xantusia riversiana reticulata)

“…Islands face similar threats to mainland habitats, such as habitat degradation and global climate change [4, 5]. However, island endemics are also sensitive to loss of genetic diversity and stochastic population fluctuations caused by the small size and isolation of their habitat [6, 7].…”

Energetic compensation is historically contingent and not supported for small mammals in South American or Asian deserts

“…Ecological systems face a barrage of abiotic exigencies, from seasonal patterns in climate to multi-decadal atmospheric drivers, interspersed with episodic events such as drought and storms. Global climate change (GCC) is poised to amplify some of these (Post 2013), leading to extensive discussion over ecological responses to GCC and to synergistic impacts of multiple threats to biodiversity (e.g., Brook et al 2008, Powell andLenton 2013), potentially with global implications (Brook et al 2013). Understanding how ecological assemblages will respond to current and pending threats is an increasingly urgent theme in ecology.…”