“Puppy-dog eyes didn’t just evolve for us, in domestic dogs,” says comparative anatomist Heather Smith. Her team’s work has thrown a 2019 finding1 that the muscles in dogs’ eyebrows evolved to communicate with humans in the doghouse by showing that African wild dogs also have the muscles to make the infamous pleading expression. The study was published on 10 April in The Anatomical Record2.
Now, one of the researchers who described the evolution of puppy-dog eyebrow muscles is considering what the African dog discovery means for canine evolution. “It opens a door to thinking about where dogs come from, and what they are,” says Anne Burrows, a biological anthropologist at the Duquesne University in Pittsburgh, Pennsylvania, and author of the earlier paper.
Evolution of canine eyebrows
The 2019 study garnered headlines around the world when it found that the two muscles responsible for creating the sad–sweet puppy-dog stare are pronounced in several domestic breeds (Canis familiaris), but almost absent in wolves (Canis lupus).
The science of puppy dog eyes
If the social dynamic between humans and dogs drove eyebrow evolution, Smith wondered whether the highly social African wild dog might also have expressive brows.
African wild dogs (Lycaon pictus) are native to sub-Saharan Africa. Between 1997 and 2012, their numbers dropped by half in some areas. With only 8,000 or so remaining in the wild, studying them is difficult but crucial for conservation efforts.
Smith, who is based at Midwestern University in Glendale, Arizona, and her colleagues dissected a recently deceased African wild dog from Phoenix Zoo. They found that both the levator anguli oculi medalis (LAOM) and the retractor anguli oculi lateralis (RAOL) muscles, credited with creating the puppy-dog expression, were similar in size to those of domestic dog breeds.
“We could see distinct fibres that are very prominent, very robust,” says Smith. Although the researchers only looked at one African wild dog, Smith says it’s unlikely that such a large and well-developed muscle would be present in one animal and not others.
A communication strategy
The team proposes that the gregarious African wild dogs evolved these muscles to communicate with each other. They use a range of vocal cues to organize hunts and share resources, but until now, non-vocal strategies haven’t been studied.
Burrows speculates that more dog species might have muscles for facial expression than the researchers realized when they compared wolves and domestic dogs. “I wonder if these muscles have been around for a really long time and wolves are the ones that lost them.”
Muhammad Spocter, an anatomist at Des Moines University in West Des Moines, Iowa, says the study is exciting, but cautions against making assumptions about wild dog behaviour based on their physical structure. “Just because the anatomy is there, is it being used?” says Spocter. “And how is it being used?”
Growing evidence indicates that insects such as bees show some forms of consciousness, according to a new scientific statement.Credit: Phil Savoie/Nature Picture Library
Crows, chimps and elephants: these and many other birds and mammals behave in ways that suggest they might be conscious. And the list does not end with vertebrates. Researchers are expanding their investigations of consciousness to a wider range of animals, including octopuses and even bees and flies.
Armed with such research, a coalition of scientists is calling for a rethink in the animal–human relationship. If there’s “a realistic possibility” of “conscious experience in an animal, it is irresponsible to ignore that possibility in decisions affecting that animal”, the researchers write in a document they call The New York Declaration of Animal Consciousness. Issued today during a meeting in New York City, the declaration also says that there is a “realistic possibility of conscious experience” in reptiles, fish, insects and other animals that have not always been considered to have inner lives, and “strong scientific support” for aspects of consciousness in birds and mammals.
As the evidence has accumulated, scientists are “taking the topic seriously, not dismissing it out of hand as a crazy idea in the way they might have in the past,” says Jonathan Birch, a philosopher at the London School of Economics and Political Science and one of the authors of the declaration.
The document, which had around 40 signatories early today, doesn’t state that there are definitive answers about which species are conscious. “What it says is there is sufficient evidence out there such that there’s a realistic possibility of some kinds of conscious experiences in species even quite distinct from humans,” says Anil Seth, director of the Centre for Consciousness Science at the University of Sussex near Brighton, UK, and one of the signatories. The authors hope that others will sign the declaration and that it will stimulate both more research into animal consciousness and more funding for the field.
Blurry line
The definition of consciousness is complex, but the group focuses on an aspect of consciousness called sentience, often defined as the capacity to have subjective experiences, says Birch. For an animal, such experiences would include smelling, tasting, hearing or touching the world around itself, as well as feeling fear, pleasure or pain — in essence, what it is like to be that animal. But subjective experience does not require the capacity to think about one’s experiences.
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Non-human animals cannot use words to communicate their inner states. To assess consciousness in these animals, scientists often rely on indirect evidence, looking for certain behaviours that are associated with conscious experiences, Birch says.
One classic experiment is the mirror test, which investigates an animal’s ability to recognize itself in a mirror. In this experiment, scientists apply a sticker or other visual mark on an animal’s body and place the animal in front of a mirror. Some animals — including chimpanzees (Pan troglodytes)1, Asian elephants (Elephas maximus)2 and cleaner fishes (Labroides dimidiatus)3 — exhibit curiosity about the mark and even try to remove it. This behaviour suggests the possibility of self-awareness, which might be a sign of consciousness.
In an experiment with crows (Corvus corone)4, the birds were trained to make a specific head gesture whenever they saw a coloured square on a screen, a task they carried out with high accuracy. While the birds performed the task, scientists measured the activity in a region of their brain associated with high-level cognition. The birds’ brain activity correlated with what the birds were reporting, not with what they were actually shown. This suggests that they were aware of what they were perceiving, another potential marker of consciousness.
Invertebrate inner lives?
Another experiment showed that octopuses (Octopus bocki)5, when picking between two chambers, avoided one where they had previously received a painful stimulus in favour of one where they were given an anaesthetic. This suggests that they experience and actively avoid pain, which some researchers think indicates conscious experience.
Research shows that octopuses avoid pain, which some scientists take as a sign of consciousness.Credit: Brandon Cole/Nature Picture Library
Investigations of fruit flies (Drosophila melanogaster) show that they engage in both deep sleep and ‘active sleep’, in which their brain activity is the same as when they’re awake6. “This is perhaps similar to what we call rapid eye movement sleep in humans, which is when we have our most vivid dreams, which we interpret as conscious experiences,” says Bruno van Swinderen, a biologist at the University of Queensland in Brisbane, Australia, who studies fruit flies’ behaviour and who also signed the declaration.
Some suggest that dreams are key components of being conscious, he notes. If flies and other invertebrates have active sleep, “then maybe this is as good a clue as any that they are perhaps conscious”.
Animal minds
Other researchers are more sceptical about the available evidence on animal consciousness. “I don’t think there is basically any decisive evidence so far,” says Hakwan Lau, a neuroscientist at the Riken Center for Brain Science in Wako, Japan.
Lau acknowledges that there is a growing body of work showing sophisticated perceptual behaviour in animals, but he contends that that’s not necessarily indicative of consciousness. In humans, for example, there is both conscious and unconscious perception. The challenge now is to develop methods that can adequately distinguish between the two in non-humans.
Seth responds that, even in the absence of definitive answers, the declaration might still have a positive influence in shaping policies relating to animal ethics and welfare.
For van Swinderen, the time is right to consider whether most animals might be conscious. “We are experiencing an artificial-intelligence revolution where similar questions are being asked about machines. So it behoves us to ask if and how this adaptive quality of the brain might have evolved in nature.”
In January 2023, the US Food and Drug Administration (FDA) approved lecanemab — an antibody medication that decreases β-amyloid protein build-up in the brain — as a treatment for Alzheimer’s disease. Pivotal evidence came from a large, randomized trial of people with early-stage Alzheimer’s, which afflicts around 32 million people worldwide. By the end of that 18-month study1, patients in the placebo group scored on average 1.66 points worse than their performance at baseline on a standard dementia test, which assesses cognitive and functional changes over time through interviews with a patient and their caregiver. The mean score of treated participants, by comparison, worsened by 1.21 points — a 27% slowing of cognitive decline.
But is this improvement meaningful for patients and their families?
Nature Index 2024 Health sciences
There are two major categories of drugs used to treat Alzheimer’s disease and other progressive conditions: symptomatic drugs, which treat the symptoms, and disease-modifying drugs, which target the root cause. Donepezil and rivastigmine, for example, are symptomatic drugs that boost the activity of chemicals in the brain to compensate for declines in cognitive and memory function caused by Alzheimer’s disease, but they cannot stop its progression. Lecanemab, developed jointly by Japanese pharmaceutical company Eisai and American biotechnology firm Biogen, targets the underlying issue of amyloid build-up in the brain, and in doing so, could fundamentally change the course of the disease.
An important feature of disease-modifying drugs is that their benefits are cumulative. Studies of patients with multiple sclerosis, for example, have shown the benefits of starting disease-modifying drugs earlier in the course of the disease compared with later, including improved mortality rates and reduced disability in the long term. Being able to quantify how long a disease-modifying drug can delay or halt the progression of Alzheimer’s disease could change how researchers understand — and communicate — its benefits.
In studies of potential disease-modifying drugs for Alzheimer’s disease, there has always been a tension between being able to produce a treatment effect and being able to measure it, says Suzanne Hendrix, statistician and founder of the clinical trials consulting firm Pentara in Salt Lake City, Utah. Clinical trials generally enrol early-stage patients — those with mild cognitive impairment and evidence of brain amyloid — because amyloid-targeting therapies have the best chance of working if given well before the disease takes hold. But in the early stages, patients deteriorate so gradually that it can be difficult to perceive the impact of a disease-modifying drug using standardized tests.
At a scientific meeting in 2009, Hendrix recalls being pulled aside by an executive at Eisai, who told her: “Nobody’s measuring this disease right. Until we measure the most progressive aspects of disease, we’re not going to be able to see treatment effects.”
Source: Institute for Health Metrics and Evaluation; Cummings, J. L., Goldman, D. P., Simmons-Stern, N. R., Ponton, E. Alzheimers Dement.18, 469–477 (2022)
Hendrix and other researchers are exploring time-based metrics as a new approach. Savings of time, measured as prolonged quality of life after 18 months of treatment, for example, is “much easier to talk about” than point differences on cognitive and functional scales, says Lars Rau Raket, a statistician at the Copenhagen, Denmark, branch of US pharmaceutical company Eli Lilly. For early-stage Alzheimer’s patients, says Racket, “it’s about how much you can extend the time in the ‘good parts’ — in the milder stages of disease”.
Straight line to time
To come up with a time-based approach, Hendrix and her colleagues pooled parts of several rating scales from standard dementia tests to develop a new tool called that picks up on subtle changes that occur in early Alzheimer’s. By zeroing in on where changes are more pronounced in these early stages, such as a diminished ability to juggle tasks or to recall past events, the team could track the progression of several key features of the disease.
To measure the effectiveness of disease-modifying treatments on these key features as units of time, the researchers used clinical outcomes from placebo and treated participants in a phase II trial of another amyloid-lowering therapy, donanemab. They calculated that over the 76-week duration of the trial, overall disease progression was delayed by 5.2 months.
In a paper published last year2, when he was working for Danish firm Novo Nordisk, in a lab just outside Copenhagen, Raket took a similar approach to calculating treatment effects in terms of time. But their methods differed in some ways. Whereas Hendrix’s work focused on calculating time savings across multiple outcomes, Raket used multiple models to calculate time savings for each outcome measure.
The idea of time-based models seems to be gaining traction. They were used as exploratory measures in a phase III trial of donanemab, conducted by Eli Lilly and Company, and published in JAMA last year3. Eisai also showed a time-based analysis in a 2022 presentation of its phase III lecanemab data at the Clinical Trials on Alzheimer’s Disease meeting in San Francisco. In those analyses, participants treated with lecanemab took 25.5 months to reach the same degree of worsening on a common dementia test as the placebo group did at 18 months — a time saving of 7.5 months.
Raket says he has been approached by several people in the pharmaceutical industry and academia, and some are working with him to apply the concept to their research. At the 2023 Alzheimer’s Association International Conference in Amsterdam, Raket and his collaborators in the United States, Canada and Europe compared time-based models with conventional statistical approaches for progressive diseases, and analysed how delays in disease progression calculated with time-based methods translate to treatment differences on standard cognitive tests. “I haven’t experienced this kind of interest in my work before,” he says. Raket predicts that an increasing number of trials in the neurodegeneration space will be reporting time-savings estimates in the years to come.
Broad impacts
Beyond Alzheimer’s disease, time-saved models could be applied to other progressive conditions, including Parkinson’s disease and amyotrophic lateral sclerosis (ALS). Cancer and cardiovascular disease studies, which tend to focus on events — delaying relapse or death, or cutting the risk of heart attacks, for instance — are less suited to models that track progression. If, however, heart disease were conceptualized as a gradual worsening of blood pressure or cholesterol over time, and treatment could be shown to slow the rate of deterioration, the time-saved approach could be used to measure the treatment benefit, says Hendrix.
One benefit of time-based methods is that they could help make clinical trials less prone to being skewed by outliers, says Geert Molenberghs, a biostatistician at KU Leuven and Hasselt University, both in Belgium, who collaborates with Hendrix. For example, a small subset of people with early Alzheimer’s disease deteriorate unusually quickly. If these rapid decliners are in the treated group, they could potentially mask a drug benefit, says Molenberghs. The details become “very technical”, he says, but with time-based approaches, these rare individuals “are less influential. They have less capacity to overturn the statistics.”
Source: Institute for Health Metrics and Evaluation; Cummings, J. L., Goldman, D. P., Simmons-Stern, N. R., Ponton, E. Alzheimers Dement.18, 469–477 (2022)
Time-based metrics could impact broader conversations with health economists and policymakers. “The idea that you could take somebody who’s already in their senior years and keep them functional and not needing 24/7 care — that’s incredibly valuable information for making estimates about the true burden or cost of the disease to caregivers and society,” says John Harrison, chief science officer at Scottish Brain Sciences, a research institute in Edinburgh, Scotland. “It’s a very neat communications tool which feeds into estimates of progression, cost, strategy and, one hopes, legislation and planning.”
There are open questions that might need to be addressed before time-saved models are more widely applied in clinical trials. One is that, although time progresses linearly, not all points on that line are equally meaningful. For example, the anti-amyloid mechanism might only be beneficial in the early stages of Alzheimer’s disease, says Ron Petersen, a neurologist at Mayo Clinic in Rochester, Minnesota. “By the time the person progresses to, say, moderate dementia, modifying amyloid probably isn’t going to make any difference.”
Hendrix is hopeful that the time-saved idea can be further developed and applied to clinical trials in the future, because it could make a big difference in tracking not only how effective new disease-modifying drugs are, but also in helping Alzheimer’s patients and their families to better understand the progression of the disease and how they can plan for it.
Ultimately, as more studies “start focusing on how much time we’ve saved people, all of the effects that we see will be more relevant” to people’s daily lives, Hendrix says.
One of world’s largest oil platforms, the North Sea’s Gullfaks C, sits on immense foundations, constructed from 246,000 cubic metres of reinforced concrete, penetrating 22 metres into the sea bed and smothering about 16,000 square metres of sea floor. The platform’s installation in 1989 was a feat of engineering. Now, Gullfaks C has exceeded its expected 30-year lifespan and is due to be decommissioned in 2036. How can this gargantuan structure, and others like it, be taken out of action in a safe, cost-effective and environmentally beneficial way? Solutions are urgently needed.
Many of the world’s 12,000 offshore oil and gas platforms are nearing the end of their lives (see ‘Decommissioning looms’). The average age of the more than 1,500 platforms and installations in the North Sea is 25 years. In the Gulf of Mexico, around 1,500 platforms are more than 30 years old. In the Asia–Pacific region, more than 2,500 platforms will need to be decommissioned in the next 10 years. And the problem won’t go away. Even when the world transitions to greener energy, offshore wind turbines and wave-energy devices will, one day, also need to be taken out of service.
Source: S. Gourvenec et al. Renew. Sustain. Energy Rev.154, 111794 (2022).
There are several ways to handle platforms that have reached the end of their lives. For example, they can be completely or partly removed from the ocean. They can be toppled and left on the sea floor. They can be moved elsewhere, or abandoned in the deep sea. But there’s little empirical evidence about the environmental and societal costs and benefits of each course of action — how it will alter marine ecosystems, say, or the risk of pollution associated with moving or abandoning oil-containing structures.
So far, politics, rather than science, has been the driving force for decisions about how to decommission these structures. It was public opposition to the disposal of a floating oil-storage platform called Brent Spar in the North Sea that led to strict legislation being imposed in the northeast Atlantic in the 1990s. Now, there is a legal requirement to completely remove decommissioned energy infrastructure from the ocean in this region. By contrast, in the Gulf of Mexico, the idea of converting defunct rigs into artificial reefs holds sway despite a lack of evidence for environmental benefits, because the reefs are popular sites for recreational fishing.
A review of decommissioning strategies is urgently needed to ensure that governments make scientifically motivated decisions about the fate of oil rigs in their regions, rather than sleepwalking into default strategies that could harm the environment. Here, we outline a framework through which local governments can rigorously assess the best way to decommission offshore rigs. We argue that the legislation for the northeast Atlantic region should be rewritten to allow more decommissioning options. And we propose that similar assessments should inform the decommissioning of current and future offshore wind infrastructure.
Challenges of removing rigs
For the countries around the northeast Atlantic, leaving disused oil platforms in place is an emotive issue as well as a legal one. Environmental campaigners, much of the public and some scientists consider anything other than the complete removal of these structures to be littering by energy companies1. But whether rig removal is the best approach — environmentally or societally — to decommissioning is questionable.
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There has been little research into the environmental impacts of removing platforms, largely owing to lack of foresight2. But oil and gas rigs, both during and after their operation, can provide habitats for marine life such as sponges, corals, fish, seals and whales3. Organisms such as mussels that attach to structures can provide food for fish — and they might be lost if rigs are removed4. Structures left in place are a navigational hazard for vessels, making them de facto marine protected areas — regions in which human activities are restricted5. Another concern is that harmful heavy metals in sea-floor sediments around platforms might become resuspended in the ocean when foundations are removed6.
Removing rigs is also a formidable logistical challenge, because of their size. The topside of a platform, which is home to the facilities for oil or gas production, can weigh more than 40,000 tonnes. And the underwater substructure — the platform’s foundation and the surrounding fuel-storage facilities — can be even heavier. In the North Sea, substructures are typically made of concrete to withstand the harsh environmental conditions, and can displace more than one million tonnes of water. In regions such as the Gulf of Mexico, where conditions are less extreme, substructures can be lighter, built from steel tubes. But they can still weigh more than 45,000 tonnes, and are anchored to the sea floor using two-metre-wide concrete pilings.
Huge forces are required to break these massive structures free from the ocean floor. Some specialists even suggest that the removal of the heaviest platforms is currently technically impossible.
And the costs are astronomical. The cost to decommission and remove all oil and gas infrastructure from UK territorial waters alone is estimated at £40 billion (US$51 billion). A conservative estimate suggests that the global decommissioning cost for all existing oil and gas infrastructure could be several trillion dollars.
Mixed evidence for reefing
In the United States, attitudes to decommissioning are different. A common approach is to remove the topside, then abandon part or all of the substructure in such a way that it doesn’t pose a hazard to marine vessels. The abandoned structures can be used for water sports such as diving and recreational fishing.
This approach, known as ‘rigs-to-reefs’, was first pioneered in the Gulf of Mexico in the 1980s. Since its launch, the programme has repurposed around 600 rigs (10% of all the platforms built in the Gulf), and has been adopted in Brunei, Malaysia and Thailand.
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Converting offshore platforms into artificial reefs is reported to produce almost seven times less air-polluting emissions than complete rig removal7, and to cost 50% less. Because the structures provide habitats for marine life5, proponents argue that rigs increase the biomass in the ocean8. In the Gulf of California, for instance, increases in the number of fish, such as endangered cowcod (Sebasteslevis) and other commercially valuable rockfish, have been reported in the waters around oil platforms6.
But there is limited evidence that these underwater structures actually increase biomass9. Opponents argue that the platforms simply attract fish from elsewhere10 and leave harmful chemicals in the ocean11. And because the hard surface of rigs is different from the soft sediments of the sea floor, such structures attract species that would not normally live in the area, which can destabilize marine ecosystems12.
Evidence from experts
With little consensus about whether complete removal, reefing or another strategy is the best option for decommissioning these structures, policies cannot evolve. More empirical evidence about the environmental and societal costs and benefits of the various options is needed.
To begin to address this gap, we gathered the opinions of 39 academic and government specialists in the field across 4 continents13,14. We asked how 12 decommissioning options, ranging from the complete removal of single structures to the abandonment of all structures, might impact marine life and contribute to international high-level environmental targets. To supplement the scant scientific evidence available, our panel of specialists used local knowledge, professional expertise and industry data.
The substructures of oil rigs can provide habitats for a wealth of marine life.Credit: Brent Durand/Getty
The panel assessed the pressures that structures exert on their environment — factors such as chemical contamination and change in food availability for marine life — and how those pressures affect marine ecosystems, for instance by altering biodiversity, animal behaviour or pollution levels. Nearly all pressures exerted by leaving rigs in place were considered bad for the environment. But some rigs produced effects that were considered beneficial for humans — creating habitats for commercially valuable species, for instance. Nonetheless, most of the panel preferred, on balance, to see infrastructure that has come to the end of its life be removed from the oceans.
But the panel also found that abandoning or reefing structures was the best way to help governments meet 37 global environmental targets listed in 3 international treaties. This might seem counter-intuitive, but many of the environmental targets are written from a ‘what does the environment do for humans’ perspective, rather than being focused on the environment alone.
Importantly, the panel noted that not all ecosystems respond in the same way to the presence of rig infrastructure. The changes to marine life caused by leaving rigs intact in the North Sea will differ from those brought about by abandoning rigs off the coast of Thailand. Whether these changes are beneficial enough to warrant alternatives to removal depends on the priorities of stakeholders in the region — the desire to protect cowcod is a strong priority in the United States, for instance, whereas in the North Sea, a more important consideration is ensuring access to fishing grounds. Therefore, rig decommissioning should be undertaken on a local, case-by-case basis, rather than using a one-size-fits-all approach.
Legal hurdles in the northeast Atlantic
If governments are to consider a range of decommissioning options in the northeast Atlantic, policy change is needed.
Current legislation is multi-layered. At the global level, the United Nations Convention on the Law of the Sea (UNCLOS; 1982) states that no unused structures can present navigational hazards or cause damage to flora and fauna. Thus, reefing is allowed.
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But the northeast Atlantic is subject to stricter rules, under the OSPAR Convention. Named after its original conventions in Oslo and Paris, OSPAR is a legally binding agreement between 15 governments and the European Union on how best to protect marine life in the region (see go.nature.com/3stx7gj) that was signed in the face of public opposition to sinking Brent Spar. The convention includes Decision 98/3, which stipulates complete removal of oil and gas infrastructure as the default legal position, returning the sea floor to its original state. This legislation is designed to stop the offshore energy industry from dumping installations on mass.
Under OSPAR Decision 98/3, leaving rigs as reefs is prohibited. Exceptions to complete removal (derogations) are occasionally allowed, but only if there are exceptional concerns related to safety, environmental or societal harms, cost or technical feasibility. Of the 170 structures that have been decommissioned in the northeast Atlantic so far, just 10 have been granted derogations. In those cases, the concrete foundations of the platforms have been left in place, but the top part of the substructures removed.
Enable local decision-making
The flexibility of UNCLOS is a more pragmatic approach to decommissioning than the stringent removal policy stipulated by OSPAR.
We propose that although the OSPAR Decision 98/3 baseline position should remain the same — complete removal as the default — the derogation process should change to allow alternative options such as reefing, if a net benefit to the environment and society can be achieved. Whereas currently there must be an outstanding reason to approve a derogation under OSPAR, the new process would allow smaller benefits and harms to be weighed up.
The burden should be placed on industry officials to demonstrate clearly why an alternative to complete removal should be considered not as littering, but as contributing to the conservation of marine ecosystems on the basis of the best available scientific evidence. The same framework that we used to study global-scale evidence in our specialist elicitation can be used to gather and assess local evidence for the pros and cons of each decommissioning option. Expert panels should comprise not only scientists, but also members with legal, environmental, societal, cultural and economic perspectives. Regions outside the northeast Atlantic should follow the same rigorous assessment process, regardless of whether they are already legally allowed to consider alternative options.
For successful change, governments and legislators must consider two key factors.
Get buy-in from stakeholders
OSPAR’s 16 signatories are responsible for changing its legislation but it will be essential that the more flexible approach gets approval from OSPAR’s 22 intergovernmental and 39 non-governmental observer organizations. These observers, which include Greenpeace, actively contribute to OSPAR’s work and policy development, and help to implement its convention. Public opinion in turn will be shaped by non-governmental organizations15 — Greenpeace was instrumental in raising public awareness about the plan to sink Brent Spar in the North Sea, for instance.
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Transparency about the decision-making process will be key to building confidence among sceptical observers. Oil and gas companies must maintain an open dialogue with relevant government bodies about plans for decommissioning. In turn, governments must clarify what standards they will require to consider an alternative to removal. This includes specifying what scientific evidence should be collated, and by whom. All evidence about the pros and cons of each decommissioning option should be made readily available to all.
Oil and gas companies should identify and involve a wide cross-section of stakeholders in decision-making from the earliest stages of planning. This includes regulators, statutory consultees, trade unions, non-governmental organizations, business groups, local councils and community groups and academics, to ensure that diverse views are considered.
Conflict between stakeholders, as occurred with Brent Spar, should be anticipated. But this can be overcome through frameworks similar to those between trade unions and employers that help to establish dialogue between the parties15.
The same principle of transparency should also be applied to other regions. If rigorous local assessment reveals reefing not to be a good option for some rigs in the Gulf of Mexico, for instance, it will be important to get stakeholder buy-in for a change from the status quo.
Future-proof designs
OSPAR and UNCLOS legislation applies not only to oil and gas platforms but also to renewable-energy infrastructure. To avoid a repeat of the challenges that are currently being faced by the oil and gas industry, decommissioning strategies for renewables must be established before they are built, not as an afterthought. Structures must be designed to be easily removed in an inexpensive way. Offshore renewable-energy infrastructure should put fewer pressures on the environment and society — for instance by being designed so that it can be recycled, reused or repurposed.
If developers fail to design infrastructure that can be removed in an environmentally sound and cost-effective way, governments should require companies to ensure that their structures provide added environmental and societal benefits. This could be achieved retrospectively for existing infrastructure, taking inspiration from biodiversity-boosting panels that can be fitted to the side of concrete coastal defences to create marine habitats (see go.nature.com/3v99bsb).
Governments should also require the energy industry to invest in research and development of greener designs. On land, constraints are now being placed on building developments to protect biodiversity — bricks that provide habitats for bees must be part of new buildings in Brighton, UK, for instance (see go.nature.com/3pcnfua). Structures in the sea should not be treated differently.
If it is designed properly, the marine infrastructure that is needed as the world moves towards renewable energy could benefit the environment — both during and after its operational life. Without this investment, the world could find itself facing a decommissioning crisis once again, as the infrastructure for renewables ages.
