If it did nothing else, the emergence of Covid-19 a year ago underlined for all of us the importance of anticipating and preparing for – and, as appropriate, steering the course of – things that might happen in the future.

That is, in a nutshell, the goal of the 2021 horizon scan of emerging global biological conservation issues recently published in the journal Trends in Ecology & Evolution by the Cambridge University conservation biologist William Sutherland and a team of 24 other conservation practitioners and researchers from around the world.

The team started by identifying 97 trends with potentially large impacts on conservation and biodiversity, then trimmed the list down to the top 15 that they agreed “society may urgently need to address”.

“Recent global assessments of biological diversity and climate change indicate negative trends and a rapidly narrowing window for action to reverse these trends,” the researchers wrote. “We believe that identification of novel or emerging issues for global biological conservation should inform policymaking.”

The 2021 horizon scan is the latest in a series that stretches back more than a decade. In addition to making their predictions for the year ahead, the team members reviewed selections from the first horizon scan, published in 2009. They found that one-third of the issues identified in that scan “have since developed into major issues or caused considerable environmental impacts”.

Here are the issues that bubbled to the top in this year’s scan:

Suffocating reefs

Coral reefs have come under siege from many threats in recent decades, from invasive species to warming waters to harmful fishing practices. Increasingly worrisome is hypoxia-associated coral mortality – suffocation from a lack of oxygen due to an influx of nutrients from land or aquaculture facilities into ocean waters. Because warm water holds less oxygen than cold water, scientists fear that climate change will only make this problem worse. Deoxygenation of ocean waters has already harmed corals in relatively small spaces such as bays and lagoons. Although we know relatively little about how resilient corals might be to low oxygen, there is concern that in some cases it could be the last straw for these valuable and beleaguered ecosystems.

Iron-fortified coasts

Ocean coastlines are abundant sources of plant and animal life – and those in polar zones are becoming increasingly so due to climate change-induced melting of glacial and floating ice that contains relatively large amounts of iron. Plants need iron to photosynthesise, so melting ice stimulates plant growth. This increases coastal ecosystems’ ability to soak up planet-warming carbon dioxide from the atmosphere and potentially harmful nutrients running off land, and boosts the food supply for other living things in the area. But as the trend continues, it is also likely to alter biodiversity and ecosystem structure and complexity along polar coastlines in unknown ways, even as it enhances biological communities’ ability to mitigate climate change through carbon sequestration.

Waves of change

Heads up, ocean ecosystems: global energy trends are about to bring big waves of change. Numerous offshore oil and gas rigs as well as first-generation offshore wind turbines are slated for decommissioning in the near future. A variety of strategies could be deployed for doing so, from removing all or part of an installation, to converting it to an artificial reef, to simply abandoning it. At the same time, new ocean-based wind energy installations and natural gas wells will be coming online. These changes in ocean-sited infrastructure could have a big impact on habitat in the vicinity – for better, for worse or for both, depending on the location, the extent to which existing infrastructure has been colonised by marine life, and specific implementation strategies.

Seabird patrol

Ocean-going vessels carrying out illegal fishing activities have ways of covering their tracks, from deactivating electronic tracking systems to avoiding the use of lights at night. The difficulty of finding such covertly operating boats on the vast open seas can be a limiting factor in efforts to prevent illegal activities that lead to overfishing and biodiversity degradation. In an interesting twist on surveillance, scientists are looking at enlisting albatrosses and other ocean-going birds to help track down troublemakers. The birds, which follow fishing vessels in hopes of grabbing morsels, can be fitted with transmitters that can help enforcement officials to find them. Work is already under way to evaluate the approach – including consideration of the extent to which it might put the birds themselves at risk of harm.

Location spoofing

Although seabirds may be attracted to fishing boats, they’re not quite as helpful when it comes to tracking vessels that aren’t flinging fish bits off the back. It is possible to identify and pinpoint the location of most such ships using global navigation satellite system (GNSS) and automatic identification systems (AIS). However, technologies are emerging that allow those wishing to avoid detection due to surreptitious activities to muddle their identification and coordinates. Conservation biologists speculate that such technologies could make it easier to illegally transport animals or animal parts, engage in illegal mining or conduct other covert activities. Efforts are under way to develop technologies to thwart such deceptive practices, but it could be a decade before they are ready to deploy.

Long-tail hormones

It’s bad enough for pollutants to harm animals that come in contact with them. But now there is evidence that some water-polluting chemicals that alter endocrine systems in fish can get passed to future generations as well. By mimicking or blocking the proper function of hormones, such compounds, which include many used in households and on farms, can cause deformities and fertility issues. And now it appears that in some species, parents can pass those disruptions to the next generation. Concerns are growing that this long-tail impact will be found in other animals as well.

Low-hanging clouds

Among the little-known prospective victims of climate change are the low clouds that hang over coastal oceans near the equator, helping to cool the atmosphere. The nature and extent of these clouds depend on a variety of conditions that are expected to change as our climate warms, including ocean temperatures, air movement in the atmosphere and the layout of coastal lands. Changes in the cloud cover, in turn, could affect the clouds’ ability to counteract global heating and preserve the conditions in which human settlements and ecosystems have evolved to thrive, and could exacerbate fire risk in the region.

Trillion-tree trouble?

Numerous groups have begun promoting extensive planting of carbon dioxide-absorbing trees as a way to help counter the climate-disrupting rise in the concentration of greenhouse gases in Earth’s atmosphere. But massive tree-planting efforts are not without concerns. Even as proponents tout the approach to climate change mitigation, others warn of potential problems. For one thing, poorly sited plantations could end up replacing ecosystems that sequestered more carbon than the trees do. For another, biodiversity could take a hit in the process as species-rich native habitats are replaced by monoculture plantations with the primary goal of sucking away CO₂. Careful planning will be needed to ensure such initiatives don’t do more harm than good in the long run.

Fire prevention logging

As climate and other conditions change, the intensity and severity of wildfires are increasing in North America, Australia, central Africa and elsewhere around the world. One strategy that has been proposed to cut the risk is to reduce the number of trees available to burn. Some research suggests that such a strategy could do little to decrease the likelihood of harm to humans and property, and in some instances could even increase it. Nevertheless, with strong public pressure to do something about this growing problem, there is a real likelihood that policymakers will turn to tree thinning as a way to prevent wildfires – with certain but unknown impacts on the ecosystem and multiple species that call forests home.

Super sustainable farming

A quiet revolution is under way in India: the large-scale adoption of sustainable intensification as a farming practice. Across the world’s second most populous country, state-level policies are incentivising farmers to adopt a suite of practices that reduce the adverse environmental impacts of agriculture while boosting crop yields, income, health and wellbeing. To date, more than a quarter of a million farmers have adopted the new approach, which includes eliminating synthetic inputs, enhancing crop diversity, rotating crops and more. Millions more are expected to follow the practice, which is also known as natural, community-based or zero-budget farming. As success stories roll in, the initiatives could set off a snowball effect, leading other countries and farmers to follow suit.

Navigation miscues?

If you have ever mistaken a satellite for a star in the night sky, you’ve had a taste of the confusion scientists fear might face some birds, mammals and insects in the future. About 2,600 artificial satellites circle our planet, and booming communications technologies are expected to catalyse the deployment of thousands more. What do these plentiful extra points of light mean for animals that use the stars for navigational cues? No one knows for sure – but it’s a question worth investigating before permanent damage is done to populations already beleaguered by human impacts on the surface of the Earth.

Stranded energy meets bitcoin

Energy that exceeds local demand – may just go to waste due to market logistics. But what if a pop-up demand were available to use this “stranded energy” on an as-needed basis, at a discounted (but better than throwing it away) price? Recently, bitcoin mining – an energy-intensive process required to keep transactions fair – has been emerging as a possible contender. Bitcoin mining is relatively flexible when it comes to time and place, so it could create a use for these resources that gives a low payout but is better than nothing. There is some concern by those working to mitigate biodiversity-compromising climate change that using bitcoin to close the use-capacity gap could boost use of fossil fuels – but there is also optimism that it may help to make renewable energy sources more economically desirable.

We’re all detectives now

If officials don’t notice or respond to environmental problems, are they still problems? Environmental quality in many regions around the world is limited by insufficient monitoring, detection, prevention and mitigation of pollution or other assaults. But that could change, thanks to emerging technologies. Because of the growing adoption of smartphones and internet connectivity, private citizens around the world are being empowered to act as environmental detectives, identifying and calling out problems they identify through social media mining. This approach has already been used to document locust swarms in east Africa. As more and more people connect, it could be applied around the world to detect and encourage responses to environmental assaults of all sorts, from water pollution to wildlife poaching.

Self-healing buildings

The development of self-healing building materials bodes well for biodiversity in a variety of ways. Such materials, which are based on a variety of inputs, including chemicals and bacteria, aim to enhance the ability of built structures to bounce back from damage without the need to repair or replace them. They could be beneficial in a number of ways. For one, they can cut greenhouse gas emissions by reducing the need to produce concrete and carry out construction projects to repair or replace damaged structures. For another, they can reduce the need to mine or quarry new materials, processes that often involve destroying habitat for plants, animals and other living things. In addition, they can shrink the production of construction debris and the accompanying increased demand for landfill space.

Baltic-Black connection

A 1,200-mile (2,000km) river-and-canal system will have environmental impacts under any circumstances. But conservation biologists are particularly concerned about the one being considered for connecting the Baltic and Black seas in Europe. Known as the E40 Waterway, it would cross the Polesia wilderness area, one of the largest in Europe, and probably affect more than 70 wildlife reserves and conservation areas. It also would pass near, and potentially disrupt, the Chernobyl exclusion zone and radioactive materials in the area. The project, which is already in motion, is expected to have numerous economic, social and environmental benefits. However, it also carries risk to biodiversity in terms of disrupted ecology and hydrology, and enhanced dispersion of non-native invasive species.