Thematic Area

Better land stewardship is needed to achieve the Paris Agreement’s temperature goal, particularly in the tropics, where greenhouse gas emissions from the destruction of ecosystems are largest, and where the potential for additional land carbon storage is greatest. As countries enhance their nationally determined contributions (NDCs) to the Paris Agreement, confusion persists about the potential contribution of better land stewardship to meeting the Agreement’s goal to hold global warming below 2°C.

For the Pacific Islands, community-based adaptation activities are crucial, and yet it remains uncertain whether they are effectively promoting long-term adaptive capacity. Here we evaluate the performance of 32 community-based adaptation initiatives across 20 rural communities in the Pacific.

Pacific Island biodiversity has a notorious record of decline and extinction which continues due to habitat loss and degradation, invasive species, overexploitation, pollution, disease and human-forced climate change. In terrestrial systems, these global and local pressures are more acute because of relatively small land to sea area, high endemism and poor adaptations to resist predation.

Many Pacific coral reefs are being damaged by habitat disturbance, pollution, fishing and climate change. Climate change is believed to be the greatest human-induced threat to corals in the Pacific region. The region needs an action plan to make cohesive decisions that will benefit coral reefs. This will enable leaders of Pacific Island countries, coral-reef managers and community members to coordinate their efforts to protect these valuable ecosystems.

Despite islands contributing only 6.7% of land surface area, they harbor ~20% of the Earth’s biodiversity, but unfortunately also ~50% of the threatened species and 75% of the known extinctions since the European expansion around the globe. Due to their geological and geographic history and characteristics, islands act simultaneously as cradles of evolutionary diversity and museums of formerly widespread lineages—elements that permit islands to achieve an outstanding endemicity.

Climate change and urbanisation in combination put great pressure on terrestrial and ocean ecosystems, vital for subsistence and wellbeing in both rural and urban areas of Pacific islands. Adaptation is urgently required. Nature-based solutions (NbS) offer great potential, with the region increasingly implementing NbS and linked approaches like ecosystem-based adaptation in response.

Tropical forests are on the front line of climate change and human sustainability challenges, being key environments in discussions of the “Anthropocene” and some of the most threatened land-based habitats on the face of the Earth. However, while it has been acknowledged that 21st-century anthropogenic alterations to tropical forests have the potential to set off major earth systems feedbacks on regional to global scales, there has been less discussion on how past human activities may have had similar impacts.

Expanding the global protected area network is critical for addressing biodiversity declines and the climate crisis. However, how climate change will affect ecosystem representation within the protected area network remains unclear. Here we use spatial climate analogs to examine potential climate-driven shifts in terrestrial ecoregions and biomes under a +2 °C warming scenario and associated implications for achieving 30% area-based protection targets.

Ocean warming is causing declines of coral reefs globally, raising critical questions about the potential for corals to adapt. In the central equatorial Pacific, reefs persisting through recurrent El Niño heatwaves hold important clues. Using an 18-year record of coral cover spanning three major bleaching events, we show that the impact of thermal stress on coral mortality within the Phoenix Island Protected Area (PIPA) has lessened over time.

Climate-driven redistribution of tuna threatens to disrupt the economies of Pacific Small Island Developing States (SIDS) and sustainable management of the world’s largest tuna fishery. Here we show that by 2050, under a high greenhouse gas emissions scenario (RCP 8.5), the total biomass of three tuna species in the waters of ten Pacific SIDS could decline by an average of 13% (range =−5% to −20%) due to a greater proportion of fish occurring in the high seas.