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1
Renewable energy and biodiversity: 1
Implications for transitioning to a Green Economy 2
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Abstract 7
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This extensive literature review identifies the impacts of different renewable energy 9
pathways on ecosystems and biodiversity, and the implications of these impacts for 10
transitioning to a Green Economy. While the higher penetration of renewable energy is 11
currently a backbone of Green Economy efforts, an emerging body of literature 12
demonstrates how the renewable energy sector can affect ecosystems and biodiversity. The 13
current review synthesizes the existing knowledge at the interface of renewable energy and 14
biodiversity accross the five drivers of ecosystem change and biodiversity loss of the 15
Millennium Ecosystem Assessment (MA) framework (i.e. habitat loss/change, pollution, 16
overexploitation, climate change and introduction of invasive species). It identifies the main 17
impacts and key mechanisms for a number of different renewable energy pathways, 18
including solar, wind, hydro, ocean, geothermal and bioenergy. Our review demonstrates 19
that while all reviewed renewable energy pathways are associated (directly or indirectly) 20
with all of the five MA drivers of ecosystem change and biodiversity loss, the actual 21
mechanisms of impact depend significantly between the different pathways (and the 22
environmental contexts within which they operate). We put these findings into perspective 23
by illustrating major knowledge/practices gaps and policy implications at the interface of 24
renewable energy, biodiversity conservation and the Green Economy. 25
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Keywords: renewable energy; biodiversity; mitigation strategies; ecosystem services; Green 27
Economy 28
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© 2016. This manuscript version is made available under the Elsevier user license
http://www.elsevier.com/open-access/userlicense/1.0/
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1. Introduction 35
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The concept of the Green Economy has gradually gained prominence amongst academics 37
and policy-makers [1][2]. The Green Economy was one of the two themes of the 2012 38
United Nations Conference on Sustainable Development (UNCSD-2012) held in Rio de 39
Janeiro, commonly known as Rio+20. The United Nations Environment Programme (UNEP) 40
has been at the forefront of the Green Economy discourse in the run-up to Rio+20, which 41
culminated in the publication of its landmark Green Economy report [2] and guidance on 42
how to formulate green economic policies, measure progress and model the future effects 43
of a transition to a Green Economy [3]. 44
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In this discourse the Green Economy is defined as an economic system that results in 46
“improved human well-being and social equity, while significantly reducing environmental 47
risks and ecological scarcities… In a green economy, growth in income and employment are 48
driven by public and private investments that reduce carbon emissions and pollution, 49
enhance energy and resource efficiency, and prevent the loss of biodiversity and ecosystem 50
services” [2] (page 15). Conserving biodiversity
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and maintaining ecosystem services
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are key 51
pillars of the efforts to transition to a Green Economy [11]. 52
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Investing in natural capital and increasing energy/resource efficiency are the two key 54
strategies to develop “green” economic sectors, as a means of transitioning towards a Green 55
Economy [2]. The former is a major strategy for economic sectors that depend on biological 56
resources, such as agriculture, forestry and fisheries. The latter is key to reducing resource 57
intensity and environmental impact to economic sectors that depend on the transformation 58
of natural capital such as manufacturing, transport and construction. 59
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1
Biodiversity is “the variability among living organisms from all sources including ... terrestrial,
marine and other aquatic ecosystems and the ecological complexes of which they are part: this
includes diversity within species, between species and of ecosystems” [4]. In the present review we
adopt the definition of biodiversity proposed by the Convention on Biological Diversity (CBD) as
it is in common usage, has policy status and is inclusive [5].
2
Ecosystem services are the benefits that humans derive directly and indirectly from
ecosystems, which contribute manifold to human wellbeing [6]. In the early ecosystem services
discourse, biodiversity was not conceptualized as an ecosystem service, but as the basis of
ecosystem services [7]. However biodiversity’s role in the provision of ecosystem services, and as
an extent its contribution to human wellbeing, is much more complicated [8][9][10].
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According to UNEP [2], the large-scale penetration of renewable energy is a key intervention 61
for greening the economy considering its
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: 62
climate change mitigation potential 63
fossil energy-saving potential 64
ability to generate “green jobs” 65
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While renewable energy currently accounts for a relatively small proportion of global final 67
energy consumption (~19.1%
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in 2013), it has the potential to provide for all human energy 68
needs [14]. In 2014, 164 countries had already adopted some type of renewable energy 69
policy (up from 48 in 2004) [13], with some of the targets being quite bold. For example the 70
EU aims to meet 20% of its total energy needs through renewable energy by 2020 [12]. 71
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However, there are some interesting and under-appreciated interplays between renewable 73
energy generation and biodiversity conservation. For example, some renewable energy 74
pathways can have major negative impacts on biodiversity by disrupting ecosystem 75
processes [15], and thus potentially take a toll on the provision of ecosystem services [16]. 76
This has been confirmed by a number of synthesis studies for individual renewable 77
technologies, e.g. wind [17][18], solar [19][20][21], hydropower [22], bioenergy [23][24] and 78
ocean energy [25][26]; as well as comparative studies between renewable and conventional 79
energy technologies [27][28] 80
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This implies that while a large-scale adoption of renewable energy could reduce GHG 82
emissions and enhance resource efficiency (two key pillars of a Green Economy), it could 83
also clash with biodiversity conservation and the maintenance of ecosystem services (a third 84
pillar of the Green Economy, as explained above). Yet, with the exception of some land-85
intensive renewable energy pathways such as bioenergy, the potential negative impacts of 86
renewable energy on biodiversity and ecosystems have been underappreciated within the 87
current Green Economy discourse [2]. 88
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The aim of this review is to systematize the evidence about the mechanisms through which 90
different renewable energy technologies can drive ecosystem change and contribute to 91
biodiversity loss, as well as identify emerging green-economic trade-offs. The review is 92
3
This triptych of policy objectives often features in policy frameworks that aim to catalyse the
penetration of renewable energy, e.g. the EU Renewable Energy Directive [12].
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Of which 10.1% came from modern renewables and 9% from traditional biomass [13].
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structured alongside the five direct drivers of ecosystem change and biodiversity loss 93
identified in the Millennium Ecosystem Assessment (MA)
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; namely habitat loss/change, 94
overexploitation, introduction of invasive species, pollution and climate change. Several 95
knowledge synthesis exercises, including follow-ups to the MA from the Intergovernmental 96
Platform on Biodiversity and Ecosystem Services (IPBES), have discussed how the direct 97
drivers of ecosystem change emerge in different parts of the world, and are linked to a 98
multitude of human interventions [6][29][30]. A deeper exposition of the links between 99
these direct drivers and biodiversity loss can be found elsewhere [6][7][31][32]. 100
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The present study initially identifies through an extensive literature review the main 102
mechanisms of ecosystem change and biodiversity loss for each renewable energy 103
technology, and the main interventions that can mitigate negative biodiversity outcomes. 104
The renewable energy technologies covered include solar (Section 2), wind (Section 3), 105
hydro (Section 4), bioenergy (Section 5), ocean (Section 6) and geothermal energy (Section 106
7)
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. We focus on renewable energy technologies that have moved beyond the laboratory 107
phase
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, as it allows us identify the impact mechanisms based on empirical studies, rather 108
than solely relying on hypotheses or simulations. Section 8.1 summarizes the current 109
evidence across the different MA drivers of ecosystem change and biodiversity loss. Section 110
8.2 identifies key knowledge/practice gaps and offers suggestions on how to better capture 111
biodiversity trade-offs during the planning of large-scale renewable energy projects. Finally, 112
Section 8.3 discusses some of the key policy implications at the interface or renewable 113
energy, biodiversity conservation and the Green Economy. 114
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2 Solar energy 116
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2.1 Background 118
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Solar energy harnesses the power of the sun to generate electricity either directly through 120
photovoltaic (PV) cells, or indirectly by means of concentrated solar power (CSP). CSP 121
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These drivers of ecosystem change and biodiversity loss share significant similarities with those
of subsequent initiatives such as TEEB [29] and IPBES [30].
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There is a large body of relevant literature for some renewable energy sources (e.g. hydro,
bioenergy) and a lack for others (e.g. ocean, geothermal). For this reason our review, rather than
being exhaustive, it attempts to identify the key mechanisms through which each of these
renewable energy technologies contribute to ecosystem change and biodiversity loss.
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For example, we do not consider some advanced renewable energy technologies such as 3
rd
generation biofuels (algal biofuels) that have not been deployed beyond laboratory conditions
[13], even though they might have some impact on ecosystems and biodiversity.
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technologies use arrays of mirrors that track the sun and continuously reflect its rays to a 122
point (heliostats) to heat a working liquid, which is then used to generate electricity in a 123
conventional turbine
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. Emerging solar energy technologies also use concentrated sunlight on 124
higher quality PVs
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. CSP generally requires large areas to be effective, while solar PV panels 125
may be distributed and mounted on any surface exposed to the sun, making them ideal for 126
integration into the urban environment or man-made structures. 127
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Large-scale solar energy generation is usually referred to as Utility Scale Solar Energy (USSE) 129
and has a typical lifespan of 25-40 years. Solar energy generation has increased rapidly in the 130
past decades. By 2014 177 GW of solar PV and 4.4 GW of solar CSP have been installed 131
globally [13]. 132
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The ecological impacts of solar energy are often assumed to be negligible [15]. However 134
USSE can affect ecosystems in multiple ways throughout its lifecycle (i.e. construction–135
operation–decommission) [33] although currently, many of these effects are hypothesized 136
with little peer-reviewed evidence available [27]. 137
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2.2 Drivers of ecosystem change and biodiversity loss 139
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Most of the well-documented effects of solar energy on ecosystems and biodiversity 141
manifest through the loss and change of habitats. This is because the development of solar 142
energy infrastructure can take up significant amounts of land modifying and fragmenting 143
habitats in the process. 144
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Regarding habitat loss, solar power infrastructure, and especially USSE, increasingly occupies 146
substantial tracts of land but its design, footprint and land-use efficiency can vary 147
considerably [21]. Supporting infrastructure such as access roads and electrical equipment, 148
combined with the spacing requirement of the panels, can result in the actual space 149
requirement of solar power developments being around 2.5 times the area of the panels 150
themselves [20]. 151
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CSP can have a ‘tower power’ configuration where mirrors focus solar energy to a central tower,
or a trough system of parabolic mirrors that reflect heat onto the focal point of the array.
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CPV (Concentrator photovoltaic) systems use lenses and sun-trackers to concentrate sunlight
onto PV cells and are more akin to conventional PV in design but as yet, have experienced
relatively limited deployment.