The effects of climate change vary hugely across political
borders, and have wide-ranging impacts on different communities and
environments. Climate policy responses must recognise this global
interconnectedness, and integrate international cooperation with effective
local action. This is why global treaties such as the Paris
Agreement are so important in the fight against climate change, but
individual nations must also do their bit to achieve the objectives set out in
the agreement. In Environments without Borders (part of Research Without
Borders), a panel debate hosted by Bristol Doctoral College and the Cabot
Institute on Wednesday 10th May, we will discuss some of these
issues, using examples from our research on particular challenges facing our
global ocean and water environments.
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Iceberg photo taken on a research trip to Antarctica, by
Eric Mackie
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Rising Sea Levels
Many climate change impacts require a policy response that
balances mitigation with adaptation. Mitigation, by reducing global greenhouse
gas emissions to achieve a zero-carbon economy, can drastically reduce some of
the worst effects of climate change. However, we are already committed to
certain climate change impacts, and these will require humanity to adapt. Sea
level rise is a prime example. Global sea level has already risen 20cm since 1900, and the rate of sea level rise is
increasing. We know this trend will continue throughout the 21st century
and beyond, but the question is, how much will sea level rise, and how fast?
Projections of global sea level rise by 2100 range from a further 30cm, assuming drastic mitigation action, to 1m or more in “business-as-usual” scenarios with
increasing carbon emissions. Cutting carbon emissions can hugely reduce the
number of people at risk of displacement by sea level rise globally, from up to 760 million in a scenario with 4°C of warming, down to 130 million if warming is limited to 2°C in line with
the Paris Agreement. Mitigation is therefore essential if we want to avoid the
worst effects, but adaptation is also necessary to ensure humanity is resilient
to sea level rise that is already locked in.
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A coastal scene taken on a research trip in the South
Pacific, by Alice Venn
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Disappearing Islands
The South Pacific is home to some of the world’s states most
vulnerable to climate change impacts. Sea-level rise threatens coastal erosion,
the widespread displacement of people and the inundation of the lowest-lying
islands in Tuvalu, Kiribati and the Marshall Islands, while oceanic warming and
acidification threaten the livelihoods of many remote coastal communities. More
intense tropical cyclones, Cyclone Pam in 2015 and Winston in 2016, have
recently resulted in tragic losses of life and damages in excess of $449 million and $470 million respectively. The devastation facing
Small Island Developing States in the region, when juxtaposed with their
negligible contribution to global greenhouse gas emissions which is estimated
at just 0.03%, serves to illustrate the need for the international
community to urgently step up efforts to provide support. Enhanced financial
assistance for adaptation is essential, however this must be accompanied by
strengthened legal protection for communities, readily accessible compensation
for loss and damage, capacity building and a strengthened role for civil
society organisations giving voice to community needs and traditional knowledge
in policy-making processes.
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The Lion Fish is an example of an aggressive invasive fish
in the Caribbean Sea, and has had an impact over native species, ecosystems and
local economies.
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Invasive Aliens
Biodiversity in water environments can be adversely affected
by invasive fish species, which originate from different
sources, including marine ballast, fisheries improvements, and aquaculture.
Invasive fish species can cause environmental concerns such as changes in the
nutrients cycle, transmission of diseases, competence for resources,
displacement and extinction of native species. Success in the establishment of
invasive species depends on propagule size, physiology of the proper species,
and current biotic and abiotic factors in the invaded system. Invasive species
represent a global issue, and when combined with climate change their effects
can be sharpened. Some limiting abiotic factors are expected to change as the
climate changes, favouring new invasions and the spread of established invasive
species to new ranges. Milder winters in northern latitude lakes, worldwide
flooding and salinisation of coastal freshwater systems will provide suitable
thermal conditions, new pathways for escape and dispersion, and the increase in
dominance by invasive fish species adapted to brackish water systems. Deficient
planning for future responses in water management can also result in favourable
conditions for dispersion of undesirable aquatic organisms. For example, this
is the case with the Nile tilapia, an invasive species in tropical ecosystems
of southern Mexico and Tanzania, where flooding causes its dispersion but
alternative management policies could improve the situation. More information
see the Invasive Species
Specialists Group.
Sustainable Resource Management
Against the backdrop of climate change, which will
exacerbate the impact of human activities on natural resources, today’s
environmental challenges require above all a strong and consistent commitment
by national governments to better implement ambitious environmental policies
that they previously adopted. However, traditional decision making approaches
often are not equipped to ensure that precious resources are protected, if not
enhanced. Sustainable management of natural resources is without doubt complex
and creates conflicts between users that compete for access. For instance,
there still seems to be too great a divide between the environmental and the business
sector and these policy domains are as yet not fully integrated. Nonetheless,
there are good examples of governments (and sub-national governments) that were
successful in getting all key policy sectors on board when implementing
difficult and ambitious environmental policies. For instance, the Scottish
Government’s approach in implementing the Water Framework Directive demonstrates that with a
strong political commitment, coupled with very proactive efforts in balancing
the decision making towards more inclusive and cooperative policy processes,
and with an intense and systematic use of evidence to back up policy proposals,
it is possible to build trust between sectors and to act upon the barriers to
implementation.
It’s clear that each of these challenges requires imminent
action, but what are the right approaches, actors, and requirements to make
meaningful progress? Whether you’re a member of the public, a policy maker, or
someone working in the field, we invite you to join us at the Environments without Borders event on Wednesday
10 May for a lively and provocative debate about the challenges we face
and how, collectively, we can spur action for change.
Blog authors (and panel members): Laura De Vito is a postgraduate researcher in the
School of Geographical Sciences. Carlos Gracida Juarez is a postgraduate researcher in
the School of Biological Sciences. Alice Venn is a postgraduate researcher in the School
of Social Sciences and Law. Erik Mackie is a postgraduate researcher in the School
of Geographical Sciences, working together with the British Antarctic Survey,
and kept up a blog during his recent fieldwork in Antarctica. Blog originally posted on the Policy Bristol Blog.