As every year since 2009, the Cambridge Conservation Initiative (CCI) through its Horizon Scan project presented the planet’s 15 most urgent conservation challenges. A gathering of 31 scientists and policy makers shaped the findings, later published in Trends in Ecology & Evolution. The 15 themes identified are:
02. New sources of hydrogen to produce energy
Hydrogen has emerged as a major energy vector, driving demand for new resource streams, transport systems, and production pathways. Extracting underground or “white” hydrogen, expanding drilling and building transport networks in pristine areas pose new trade-offs. Building leak-proof infrastructure is essential to ensure a transition to hydrogen economies supports climate goals without compromising ecosystems.
03. Production of decarbonized ammonia
Ammonia (NH3) carries high energy density and serves as a key fertilizer precursor. It is typically produced with fossil fuels in energy-intensive processes. A rapid, decarbonized method uses microdroplets sprayed onto a magnetic graphite mesh coated with iron oxide, with nitrogen or air as the nebulization gas. While industrially scalable and low-cost, this method may carry environmental risks, notably nitrous oxide emissions, a potent greenhouse gas.
04. Foods derived from autotrophic hydrogen-oxidizing bacteria
Food production remains a major driver of biodiversity loss due to land conversion, emissions, overfishing, and pollution. Rising demand for protein-rich foods challenges sustainability. A growing number of firms are pursuing protein production via autotrophic hydrogen-oxidizing bacteria. If scaled rapidly, this fossil fuel-free approach could decentralize protein production and lessen environmental impacts associated with traditional farming.
05. Accelerating artificial photosynthesis
Agricultural expansion drives biodiversity loss and is limited by traditional photosynthesis, which is energy-inefficient and land-intensive. Artificial photosynthesis uses an electrocatalytic process wherein acetate from water, electricity, and carbon dioxide replaces glucose. It can be markedly more efficient than natural photosynthesis, and integrating other energy sources like wind could further reduce dependence on sunlight.
06. Carbon mineralization techniques
Applying rock dust, especially basalt, to farmland leverages soil CO2 and carbonic acid to mineralize carbon. Secondary benefits may include soils and coastal waters with lower acidity, enhanced diatom production, and reduced eutrophication. Potential downsides include heavy metal pollution and increased sedimentation or turbidity in water habitats, which could affect species adapted to low-pH conditions.
07. Decrease in worm population
Earthworms act as ecosystem engineers, driving nutrient cycling, soil fertility, and overall ecosystem health. They support global food production through soil structure and chemistry. Pesticide use appears linked to declines in earthworm populations, risking soil integrity, biodiversity, and ecosystem services.
08. Ecoacoustics to monitor soil ecology
Soil ecoacoustics uses acoustic signals to gauge soil life and quality, offering a non-intrusive method to monitor invertebrates and general soil health. Experts emphasize standardizing methods and integrating ecoacoustics with complementary tools like eDNA metabar coding to illuminate soil microbiota composition.
09. Forest fires
Wildfires driven by land use and biomass burning generate aerosols that alter solar radiation, cloud formation, and precipitation. Climate warming amplifies fire frequency and intensity. These aerosols influence atmospheric dynamics across regions, affecting food availability, habitat conditions, and climate patterns in complex ways.
10. Desktop DNA printers
Even within five years, desktop DNA printing could enable sequencing-scale capabilities that raise ecological and ethical concerns. Indirect risks include unintended genetic transfer to wild populations, potential invasive species, and shifts in land-use pressures. However, breakthroughs in genetic engineering may also enable coral resilience, control of invasive species, and disease resistance in threatened fauna.
11. Extrapolation of chemical toxicity assessments
Some chemicals, including neonics, cause delayed and unpredictable ecological effects. Emerging tools in artificial intelligence and machine learning can refine adverse outcome pathways, enabling safer use of agricultural chemicals with fewer non-target impacts.
12. NEOM Linear Skyscraper City
Saudi Arabia’s NEOM project envisions The Line, a single-street urban corridor spanning hundreds of kilometers. While marketed as sustainable, the city’s size and design raise concerns for migratory species and water demand, highlighting potential trade-offs between bold urbanism and ecological integrity.
13. Sea urchin mortality rate
Caribbean long-spined urchin populations have experienced mortality rates up to 99%, with non-native species affected across broader regions. This crisis hints at a emerging global threat to tropical ecosystems, with warming linked disease outbreaks likely to become more common in marine environments.
14. Removing CO2 from the oceans
To keep warming within 2°C, emissions cuts must be paired with ocean-based CO2 removal. Ocean fertilization, macroalgae growth and sinking, increasing alkalinity, or injecting CO2 into rock formations are among proposed methods. Yet their effectiveness and potential harms—such as oxygen depletion, nutrient imbalance, and marine life disruption—remain uncertain.
15. Rising ocean temperatures
The mesopelagic zone, extending from 200 to 1,000 meters deep, holds a quarter of the ocean volume. Warming threatens the biological carbon pump, reducing its efficiency and altering food availability for deep-sea species as remineralization accelerates.
16. Melting Antarctic ice (final concern)
Changes in Southern Ocean circulation affect water density and salinity, potentially slowing abyssal currents by 40% by mid-century. Such shifts can disrupt nutrient transport, CO2 uptake, and global climate dynamics, with wide-reaching impacts on both land and sea ecosystems.
Reference note: The Horizon Scan findings are described in Trends in Ecology & Evolution, with detailed methodology and implications discussed in the lead report. [Citation: Cambridge Conservation Initiative Horizon Scan, 2023, Trends in Ecology & Evolution; attribution to the originating researchers and institutions as noted in the study.]