Climate
change is having mixed — but mostly negative — impacts on ecosystem
services, suggest data analysed by a new study. The research, which
brings together the findings of over 100 other studies, found that 59%
of reported impacts of climate change on ecosystem services are
negative, while just 13% are positive. However, the method of research
was shown to strongly influence whether impacts are reported as positive
or negative, with expert opinion studies far more negative than other
types of study.
Climate change is having a major impact on ecosystem services. It is, therefore, essential that climate change
is integrated into assessments of ecosystem services to help avoid poor
outcomes of environmental management. Coastal planning that ignores the
effects of sea-level rise could lead to a long-term decline in
ecosystem services provided by coastal wetlands, such as flood
protection, for example.
There
are many studies which have explored climate change’s impacts on
ecosystem services, but this new study is the first to quantitatively
bring together a wide range of findings to provide an overview of the
situation. The researchers gathered and reviewed 117 research papers
from around the world that explored links between climate change and
ecosystem services. The papers were published between 2003 and 2014,
although most (78%) were published after 2011, which reflects growing
research interest in this area.
The
majority of the analyses (59%) reported negative impacts on ecosystem
services. Around a quarter (24%) reported mixed impacts, 13% were
positive and 4% were neutral. The impact varied, to some extent,
depending on what kind of ecosystem service was being assessed; for
instance, cultural ecosystem services were more likely to be negatively
affected than ‘provisioning’ ecosystem services (e.g. food and water
production).
Of
the specific types of ecosystem service, carbon sequestration was
reported to have the most varied response to climate change: 41% of
analyses suggested impacts would be mixed, 35% negative, 20.5% positive
and 3.5% neutral. Impacts of carbon dioxide (CO2) fertilisation (increased plant growth from elevated atmospheric CO2)
were most likely to be positive; 36% of analyses suggested positive
impacts; 36% negative; 14% mixed; and 14% neutral. This underscores the
researchers’ further findings that the context of each study appeared to
affect the direction of climate change impacts, whether this was due to
geography or ecosystem type — in one study in the UK, researchers
showed that temperature increases would have a negative effect on carbon
sequestration; in another study, in the Swiss Alps, researchers showed
that it would have a positive impact. Other studies revealed that carbon
sequestration response to temperature increase varied by ecosystem
type.
More
generally, the expected impacts of climate change varied according to
the geographical context of each study. Crop production was shown to be
affected variably between temperate and Mediterranean climate types in
France and also across different crop types globally, between temperate
and tropical regions. This variability extended into the marine
environment, with maximum fisheries catch potential differing between
offshore and coastal zones. This, the researchers say, highlights the
importance of conducting local and regional ecosystem-service
assessments, rather than relying on averages or aggregates from other
contexts.
Importantly,
the method of study was shown to influence the outcome. Nearly all
(94%) of studies which drew conclusions by gathering opinions from
experts were negative, and none reported positive impacts. However, just
under half (47%) of studies which used either empirical methods (i.e.
observing actual climate change impacts), or computer modelling methods,
were negative, with 29% reporting mixed impacts, 9% neutral and 15%
positive impacts.
The
authors of this study recommend that, in future, researchers should use
a variety of methods and not rely on expert opinion alone, as this may
be affected by personal motivations or ‘accessibility bias’ — a
psychological term which describes how opinions are, unintentionally,
most influenced by information that is the easiest to retrieve from
memory.
The
authors also stress how important it is for environmental management to
account for multiple, simultaneous impacts of climate change and other
drivers of change (e.g. land-use change) on ecosystems services, and
within a socioeconomic context. For example, although high levels of CO2
may help boost crop growth through fertilisation, this benefit could be
offset by declines in rainfall and shorter growing seasons, while
increased demand for crops from a growing population will affect the
scale and intensity of agriculture. However, an integrated approach was
often overlooked in the analyses, with only 17% considering how
ecosystem services may interact, in trade-offs or synergies. Other gaps
in the research included a lack of studies in regions other than Europe
and the USA and on marine ecosystem services.
Source: Runting,
R.K., Bryan, B.A., Dee, L.E., Maseyk, F.J.F., Mandle, L., Hamel, P.,
Wilson, K.A., Yetka, K., Possingham, H.P. & Rhodes, J.R. (2016).
Incorporating climate change into ecosystem service assessments and
decisions: a review. Global Change Biology. DOI: 10.1111/gcb.13457.
Contact: r.runting@uq.edu.au
Read more about: Biodiversity, Climate change and energy
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