commentary
Box 1 | Ongoing examples of climate change litigation.
• Litigation is currently ongoing before the US District Court of Oregon against the
United States Federal Government under the constitution and public trust doctrine
(ref. 33). The case is being brought by a group of youth plaintiffs who allege, inter alia,
that the United States is violating their fundamental rights protected under the US
Constitution by failing to regulate greenhouse gas emissions so as to preserve a safe
and habitable climatic system.
• A suit was filed by the Conservation Law Foundation against Exxon Mobil in late 2016
regarding adaptation to sea-level rise at the company’s refinery on the Mystic River.
• An investigation of Exxon Mobil by the New York Attorney General (NY AG) under
the Martin Act is ongoing. The Martin Act gives the NY AG powers to investigate
corporate fraud, including allegations of misleading shareholders in financial filings
and other information published by a company.
• In March 2017, three Californian coastal counties filed suit against 20 of the world’s
largest fossil fuel producers, seeking damages for their contribution to expected
damages from sea-level rise. The suit claims that that the companies obscured the
harm caused by their products, violating both consumer protection and property
protection torts at common law.
evidence clearly establishes that the relative
risk is greater than 2:1, the concepts of
‘increasing the risk’ and ‘causing the damage’
are, in effect, synonymous … In purely
scientific terms one may not ‘know’ that to
be so, but anyone using that verb in such
a context is implicitly applying a higher
standard of proof ’17.
Event-attribution science is therefore
theoretically capable of establishing
sufficient ‘causal’ connection in the
law, provided it satisfies applicable tests
for admissibility.
Scientists should of course continue
to express their findings probabilistically,
maintaining all appropriate scientific
standards necessary to achieve consensus
and meet the professional standard of care.
However, they should be aware that neither
the law nor, arguably, the general public,
adopts such rigorous standards when
drawing conclusions about cause and effect.
For example, the temperature anomalies
of the record hot summer of 2017 in
southeastern Australia were found to be
at least 50 times more likely in the current
climate than in the past (http://go.nature.
com/2uNbElb). The researchers also found
that: “In the past, a summer as hot as
2016–2017 was a roughly 1-in-500-year
event. Today, climate change has increased
the odds to roughly 1-in-50 years — a
tenfold increase in frequency. In the future,
a summer as hot as this past summer in New
South Wales is likely to happen roughly once
every five years”.
This demonstrates that attribution science
is not only linking human greenhouse
gas emissions to specific physical impacts
happening today, but that it is producing
clear evidence and warnings about increased
risk of extreme events in the future.
Implications for government
States have duties to avoid harm to their
citizens or those in their care under a range
of constitutional, common law and/or
statutory rights. Although attribution science
could play a role in providing evidence of
particularized harm in such cases, we focus
on the implications for adaptation, as the
legal basis of claims seeking mitigation have
been discussed in detail elsewhere.
Government agencies often own and
manage a wide range of public infrastructure
and assets, including utilities, roads and
public housing. All of these may require
upgrades to ensure resilience to future
climates. The state of climate science and
attribution science is particularly important
to subnational governments, including cities
that may have cause to consider scientific
evidence when carrying out their duties.
In the US, claims against governments
for failing to adapt to climate change
may be brought under existing statutory
obligations18, negligence, fraud, or takings
(land acquisition) theories19. Lawsuits
have already been filed seeking damages
for government failing to adapt to climate
change20,21, whereas insurers have already
brought claims highlighting government
failure to adequately prepare for foreseeable
flood events22.
In 2011, the Australian Local Government
Association commissioned a private law
firm to complete a comprehensive review of
the liability risks to local government that
may arise as a result of climate change23. The
report concluded that in order to mitigate
liability risks: “Councils must ensure
they keep up to date with general climate
change science and information related
to mitigation and adaptation strategies
and also information particular to their
specific local government area. Councils will
require localized information on impacts on
which they can rely when making planning
decisions and specialist advice on planning
and engineering options for other aspects
of adaptation.”
It is also interesting to note that the
UK 2008 Climate Change Act contains
provision for the national government to
request adaptation plans from agencies to
demonstrate their preparation and planning
for the impacts of climate change24, thereby
arguably assisting those agencies to mitigate
litigation risk.
Good communication between the
scientific community and those responsible
for public infrastructure is essential to ensure
appropriate adaptation and resilience and to
avoid liability.
Risks for professionals
The same liability risk that applies to
governments that own and operate assets
applies to private professionals and
companies that may design, construct,
manage or maintain public assets threatened
by climate change; for example, by wildfire or
heatwaves.
Unlike government agencies, private
professionals such as engineers may not
benefit from sovereign immunity. They could
be exposed to greater liability risk if they fail
to take increased extreme weather events into
account. Similarly, private owners of critical
infrastructure such as ports, airports and toll
roads may be contractually obliged to assess
and manage foreseeable climate-related risks.
In common-law jurisdictions (including
the US, UK, Canada and Australia), the
typical case for negligence requires proof
that the defendant owed the plaintiff a duty,
that the duty was breached and the breach
was the cause of damages suffered by the
plaintiff. Foreseeability affects each of these
elements and therefore attribution science
will probably change the reasonableness of
adhering to existing design standards that
have, at their core, assumptions about the
continued relevance of stationarity that may
no longer hold. This may have implications
for a range of contractual terms governing
the management or maintenance of both
private and public infrastructure, including
fitness for purpose and defect clauses,
warranties or indemnities.
Some professional organizations are
helping their members mitigate these
risks by producing guidance on how to
adapt their practice in the face of climatic
change25,26. However, where old and arguably
out-of-date building codes and standards
are applied automatically by architects,
engineers, planners and builders, or where
standards are not updated based on the best
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