Climate change is one of the greatest threats to global biodiversity, alongside land and sea-use change. Rising temperatures, shifting rainfall patterns and extreme weather events are altering the ecosystems that support millions of species, including UK ecosystems and habitats. Without urgent action on both climate and conservation, we face a collapse in the natural systems we depend on for survival.
Key Takeaway
The climate crisis and biodiversity loss are inseparable crises. 2024 was the first calendar year above 1.5°C (about 1.55°C, according to the WMO), although long-term warming is about 1.3–1.4°C. Monitored vertebrate populations fell by 73% on average between 1970 and 2022 (Living Planet Report 2026), and around one million species are threatened with extinction. Yet solutions exist: natural climate solutions could provide around 37% of the cost-effective mitigation needed by 2030 for a likely 2°C pathway (Griscom et al., 2017), whilst restoring ecosystems and protecting wildlife.
1.55°C
2024 Temperature
Above 1850–1900 (single year, WMO)
73%
Vertebrate Decline
Average, 1970–2022
1 Million
Species at Risk
Threatened with extinction
How Climate Change Threatens Biodiversity
The link between climate change and biodiversity loss is direct and devastating. As global temperatures rise, ecosystems face unprecedented pressures that disrupt every level of the biosphere, from the tiniest microorganisms to apex predators.
Rising Temperatures and Habitat Destruction
Temperature increases shift the ranges of countless species. Plants and animals optimized for specific climates must migrate to cooler regions or face extinction. For many species, migration isn’t possible. Mountain species have nowhere higher to climb. Polar species lose their ice-dependent habitats. Arctic permafrost thaw releases ancient carbon and destabilizes ecosystems that evolved in frozen conditions for thousands of years.
Warming also accelerates evaporation, creating water stress in wetlands, rivers, and lakes. Freshwater ecosystems are particularly vulnerable. Chalk streams in the UK are already experiencing unprecedented drought stress, threatening species like the brown trout that depend on cold, clean water.
Ocean Warming and Acidification
Our oceans have absorbed about 91% of the excess heat trapped by greenhouse gases since 1971 (IPCC AR6). This warming is catastrophic for marine life. Coral reefs—home to a quarter of all marine species despite covering less than 1% of the ocean floor—bleach when water temperatures exceed their tolerance thresholds even briefly. Bleached corals are stressed and more susceptible to disease, and prolonged bleaching events cause permanent ecosystem collapse.
Ocean acidification, caused by increased CO2 absorption, poses another threat. Lower ocean pH makes it harder for shellfish, molluscs, and pteropods to build shells and skeletons. These creatures form the base of marine food webs; their decline cascades through entire ocean ecosystems. Fish larvae are also affected, with impaired sensory and predatory abilities in more acidic conditions.
Warning
The IPCC projects that warm-water coral reefs will decline by 70–90% at 1.5°C of warming and by more than 99% at 2°C. The Global Tipping Points Report 2025 estimates that the central tipping point for warm-water reefs, about 1.2°C, has already been crossed (Global Tipping Points). This represents an imminent biodiversity crisis for marine environments.
Disruption of Seasonal Timing
Climate change is causing spring to arrive earlier in many regions. Plants flower sooner. Insects emerge earlier. But not all species shift their timing equally. Migratory birds, guided by day length and sun position, may arrive to breeding grounds after insects have peaked. Mismatched phenology—the timing of seasonal events—breaks the ecological relationships that species depend on for survival.
Research on the pied flycatcher, which breeds in Europe and winters in Africa, has linked its declines in parts of the Netherlands to this mismatch between arrival date and peak food availability.
The Most Vulnerable Species
Some species affected by climate change are far more vulnerable than others. Those with narrow geographic ranges, specialized diets, or dependence on specific climatic conditions face the steepest extinction risk.
Species Facing Highest Risk
- Polar bears – Sea ice loss eliminates hunting habitat and prey access. Population declines already documented.
- Coral reef organisms – Direct exposure to warming water and acidification. Limited dispersal capability.
- Mountain species – Alpine species have nowhere higher to migrate as temperatures warm. Pika, snow leopards, and alpine plants particularly vulnerable.
- Amphibians – Extremely sensitive to temperature and moisture changes. Dependent on specific water conditions. Fungal disease outbreaks increase with warming.
- Migratory birds – Complex climate and calendar mismatches threaten populations. Some long-distance migrants, such as the pied flycatcher, have declined where timing mismatches are strongest.
- Specialist species – Animals and plants with narrow climate tolerances and specialist diets face rapid habitat loss. Examples include the giant panda (bamboo specialist) and many insects dependent on specific host plants.
The Extinction Vortex
Climate stress doesn’t work in isolation. It compounds with the other causes of biodiversity loss — habitat destruction, pollution, and invasive species — to create an extinction vortex. Small populations in fragmented habitats lose genetic diversity, become inbred, and lose resilience to any additional stress. As climate change intensifies, these already-stressed populations face uncompromising pressure.
Species on the edge of extinction today—like the Sumatran orangutan, Northern white rhinoceros, and Vaquita dolphin—have almost no buffer against climate impacts. Even small changes in temperature or precipitation could push them over the edge into extinction.
Ecological Tipping Points
Climate systems and ecosystems contain tipping points—thresholds beyond which small additional warming triggers rapid, often irreversible changes. Crossing these tipping points could fundamentally restructure life on Earth.
Amazon Rainforest Dieback
Tipping point: 1.5–2°C warming (risk range)
The Amazon’s role as a carbon sink could flip to a carbon source, releasing billions of tonnes of CO2 and driving further warming.
Coral Reef Collapse
Tipping point: About 1.2°C (already crossed)
Warm-water reefs are already suffering repeated mass bleaching and dieback, putting at risk the quarter of marine species that depend on them.
Arctic Sea Ice Loss
Outlook: no single threshold
September Arctic sea ice is likely to disappear at least once before 2050 under all emissions scenarios the IPCC assessed, eliminating habitat for polar bears, walruses, ice seals, and algae supporting the entire Arctic food web.
Permafrost Collapse
Tipping point: 1.5– 2°C warming
Thawing permafrost releases methane and CO2, accelerating warming and destabilizing ecosystems in the Arctic and subarctic regions.
These tipping points are not isolated events. They interact and cascade. Arctic ice loss reduces the planet’s reflectivity, accelerating global warming. Amazon dieback releases carbon that warms the planet further. Permafrost collapse releases methane, a greenhouse gas around 80 times more potent than CO2 over 20 years (IPCC AR6). Once triggered, these cascades could make further warming harder to limit.
2024 was about 1.55°C above 1850–1900, but that was a single year; long-term warming is about 1.3–1.4°C. The Global Tipping Points Report 2025 warns that Earth’s climate and nature are already passing some tipping points as warming approaches 1.5°C.
Climate Change and UK Wildlife
The United Kingdom is not immune to climate impacts on biodiversity. In fact, UK wildlife is experiencing rapid changes that exemplify broader patterns of climate-driven ecological disruption.
Range Shifts and Poleward Migration
British bird and insect populations are shifting northward and upward in elevation as temperatures warm. Some warmth-loving species are expanding northwards in Britain. Cold-adapted species such as the mountain hare in the Scottish Highlands, which relies on snow cover for camouflage and predator avoidance, are more exposed as snow cover shrinks.
Many UK bird species now breed earlier than they did a few decades ago. Where their insect prey has not shifted timing in the same way, chicks can miss the peak in food during the critical breeding season.
Freshwater Ecosystem Stress
The UK’s chalk streams—iconic freshwater habitats that support species like brown trout, water voles, and aquatic plants—are under unprecedented pressure. Warming temperatures and increased evaporation reduce water flows. Extended summer droughts have caused complete flow cessation in some streams. When combined with groundwater extraction for human use, chalk streams are becoming increasingly strained.
Lowland wetlands, which support breeding populations of wading birds, are also experiencing drought stress. Extreme winter and spring flooding, meanwhile, damages nesting habitats. Wetland species face a double squeeze: wetter winters and drier summers.
Coastal Biodiversity Loss
UK coastal habitats are facing erosion driven by sea level rise and increased storm intensity. Salt marshes, shingle beaches, and cliff-top habitats that support rare plants and breeding seabirds are being squeezed between rising sea levels and human development inland. Many coastal species have nowhere to migrate.
Marine species off the British coast are also shifting. Warm-water fish species are moving north, while cold-adapted species decline. Kelp forests are vulnerable to marine heatwaves in some regions.
Disease and Invasive Species Expansion
Warmer winters allow disease-carrying organisms and invasive species to expand their ranges into the UK. The Asian (yellow-legged) hornet, a threat to honeybees and other pollinators, is not yet established in the UK, but it is detected every year: there were 161 confirmed nests in 2025, all destroyed (gov.uk). Ticks that can carry Lyme disease may also spread as winters warm.
Nature-Based Climate Solutions
The good news: nature itself is one of our most powerful allies in fighting climate change. Protecting and restoring natural ecosystems can deliver significant carbon storage while simultaneously supporting biodiversity.
Forests as Carbon Sinks
Forests absorb and store carbon dioxide on a massive scale. A mature forest can sequester tons of carbon per hectare annually. Forest restoration and protection is one of the most cost-effective climate interventions available. A 2017 study in PNAS found that natural climate solutions, including forest protection and restoration, could provide 37% of the cost-effective mitigation needed by 2030 for a likely 2°C pathway (Griscom et al.).
Beyond carbon storage, forests provide habitat for wildlife, prevent soil erosion, regulate water cycles, and support livelihoods for millions of people globally. Forest protection is a win-win for both climate and biodiversity.
Peatlands: The Overlooked Carbon Store
Peatlands are among the most carbon-dense ecosystems on the planet. UK peatlands store at least 3.2 billion tonnes of carbon (IUCN UK Peatland Programme). Yet peatlands have been drained for agriculture and forestry, converting them from carbon sinks to carbon sources. Peatland restoration—rewetting degraded peat bogs—can reverse this process and restore habitat for specialist species like curlew, adder, and sphagnum moss.
Restoring UK peatlands is critical for both carbon storage and biodiversity. Yet about 80% of UK peatland is degraded to some extent (IUCN UK Peatland Programme). Restoration efforts must expand dramatically.
Seagrass, Mangroves, and Coastal Habitats
Seagrass meadows, mangrove forests, and salt marshes are exceptional carbon sinks often called “blue carbon” ecosystems. Per unit area, they can bury carbon at rates comparable to or higher than many terrestrial forests, although rates vary widely between ecosystems. They also provide crucial nursery habitat for fish, support biodiversity, and protect coasts from storms and erosion.
However, these coastal habitats are disappearing rapidly. Mangrove forests are being converted to shrimp farms. Seagrass meadows are damaged by pollution and coastal development. Protecting and restoring these ecosystems is essential for both climate and marine biodiversity.
Key Finding
Natural climate solutions could provide around 37% of the cost-effective mitigation needed by 2030 for a likely 2°C pathway (Griscom et al., 2017). This makes ecosystem protection and restoration among the most cost-effective climate actions available.
Regenerative Agriculture and Land Use
Agricultural land covers 37% of global land area. Shifting from conventional agriculture to regenerative practices—minimizing soil disturbance, maintaining plant cover, integrating livestock sustainably—can increase soil carbon storage while improving biodiversity. Hedgerows, field margins, and diverse crop rotations provide habitat for birds, pollinators, and beneficial insects whilst supporting crop productivity.
The UK’s farming sector has enormous potential to contribute to both climate and biodiversity goals through land use changes that store carbon, maintain fertility, and restore wildlife habitat.
Biodiversity as Climate Solution: The Resilience Connection
High biodiversity doesn’t just support nature for its own sake. Biodiverse ecosystems are functionally more resilient and better equipped to withstand climate change impacts. This creates a powerful positive feedback loop: protecting biodiversity increases climate resilience, which allows ecosystems to better survive the climate changes we’ve already locked in.
Forest Diversity and Resilience
Mixed forests with diverse tree species are more resilient to drought, pests, and disease than monoculture plantations. A diverse forest with species adapted to a range of conditions maintains productivity even when climate stress affects particular species. The diversity acts as biological insurance.
Research on European forests shows that diverse forests maintain higher wood productivity under drought stress than single-species forests. Tree diversity also reduces pest outbreaks by supporting natural enemies of pests.
Coral Diversity and Recovery
Coral reefs with high species diversity recover faster from bleaching events. Diverse reefs have species with different thermal tolerances; some species survive while others are stressed, allowing the reef structure to persist. As the climate stabilizes, heat-tolerant species can gradually expand. In contrast, reefs dominated by a few species collapse completely when those species bleach.
Protecting reef diversity is not just about preserving nature—it’s about maintaining the resilience that allows these ecosystems to survive the climate impacts that are now unavoidable.
Grassland Productivity Under Extremes
Grasslands with high plant diversity maintain productivity under extreme weather better than species-poor grasslands. The variety of root depths, growing seasons, and environmental preferences means that when drought affects shallow-rooted plants, deep-rooted plants maintain productivity. When unseasonable frosts kill early-flowering plants, late-flowering plants take over. Diversity provides a buffer against climatic variability.
This principle extends across ecosystems. Whether discussing wetlands, agricultural systems, or alpine meadows, functional diversity increases resilience to climate variability. This resilience doesn’t solve the climate crisis, but it does allow ecosystems—and the people depending on them—to better withstand the inevitable impacts of warming that’s already locked in.
What Must Happen Now
The intersection of climate change and biodiversity loss represents one of humanity’s greatest challenges. Yet it also presents a clear path forward that addresses both crises simultaneously.
Immediate Actions
- Decarbonize energy systems by rapidly scaling renewable energy, improving efficiency, and phasing out fossil fuels. Limiting warming to 1.5°C preserves more ecosystems and species than higher warming scenarios.
- Protect and restore forests at a global scale. Halt deforestation immediately and invest in large-scale forest restoration in priority regions like the Amazon, Congo, and Southeast Asia.
- Restore wetlands and peatlands, particularly in the UK where peatland restoration is a proven climate and biodiversity win.
- Protect marine ecosystems by establishing marine protected areas that safeguard coral reefs, kelp forests, and fish populations critical to food security and biodiversity.
- Transform agriculture toward regenerative practices that store carbon, support biodiversity, and improve soil health.
- Fund wildlife conservation and habitat restoration for species most threatened by climate change, particularly in biodiversity hotspots.
Policy and Systemic Change
Individual actions matter, but systemic change is essential. Governments must:
- Integrate climate and biodiversity goals into all policy decisions, including mechanisms such as biodiversity net gain
- Implement carbon pricing to internalize the cost of emissions
- Invest in nature-based solutions at the scale required
- Support just transitions that protect workers and communities dependent on fossil fuel industries
- Hold corporations accountable for biodiversity impacts in supply chains
Individual Contributions
While systemic change is imperative, individuals can contribute by:
- Reducing personal carbon footprints through lower-emission transport, energy, and consumption
- Supporting businesses and politicians committed to climate action and biodiversity protection
- Participating in habitat restoration and conservation work
- Eating more plant-based foods and sustainably sourced proteins
- Creating wildlife-friendly spaces in gardens and supporting rewilding initiatives
Every action counts, but the scale must match the magnitude of the crisis. The 2030s are the critical decade. The decisions we make now will determine whether the biodiversity crisis intensifies or whether we begin meaningful recovery.
Conclusion
Climate change and biodiversity loss are not separate crises—they are two expressions of the same fundamental problem: humanity’s unsustainable relationship with the natural systems that support all life.
Rising temperatures are not simply a matter of a few degrees warmer. They trigger cascading failures in ecosystems, threaten tipping points that could fundamentally restructure the planet, and push species toward extinction at rates that IPBES says are at least tens to hundreds of times higher than the average over the past 10 million years. The 73% average decline in monitored vertebrate populations between 1970 and 2022 is not an abstract statistic—it is evidence of a living world in crisis.
Yet the same nature that is threatened by climate change is also part of the solution. Forests, wetlands, peatlands, and ocean ecosystems can sequester carbon, support biodiversity, and enhance resilience—all simultaneously. Natural climate solutions could provide around 37% of the cost-effective mitigation needed by 2030 for a likely 2°C pathway while restoring habitat and reversing biodiversity loss.
The path forward requires both rapid decarbonization of human societies and simultaneous protection and restoration of natural ecosystems at a scale never before attempted. It requires political will, financial investment, and global cooperation. It requires recognizing that the health of nature and the health of human societies are inseparable.
The window for meaningful action is closing, but it is not yet closed. The choices made in the next few years will determine whether we witness biodiversity recovery or collapse. The stakes could not be higher. The time for action is now.
