A new international study warns that the survival of penguins in the Southern Hemisphere depends on a critical shift in understanding climate change. Instead of viewing extreme weather events like marine heatwaves, storms, or heat surges as isolated incidents, scientists now emphasize that their combined, cumulative impact poses the greatest threat to all 18 penguin species. This new perspective, published in Global Change Biology, provides a vital tool for anticipating risks and designing more effective conservation policies.
The research, led by the Institut de Ciències del Mar (ICM-CSIC) in Barcelona, in collaboration with the Laboratoire LOCEAN-IPSL (Sorbonne Université) and Phillip Island Nature Parks, is the first to quantitatively assess how multiple extreme climate events interact across the full range of penguin habitats. By analyzing three decades of climate data, the team has identified the species and regions most at risk, offering actionable insights for conservation planning and policy implementation. The study highlights the urgent need for proactive, spatially informed management to safeguard penguin populations as climate extremes escalate.
A New Perspective on Climate Threats
The traditional approach to studying the impact of climate change on wildlife has often focused on single events. However, the reality is that ecosystems and the species within them are subjected to a variety of simultaneous and successive stressors. This new research moves beyond the one-off event to create a more holistic picture of the challenges penguins face. The study’s authors argue that the cumulative effects of these events—such as a marine heatwave followed by an intense storm—can have a much more devastating impact than each event would individually.
This comprehensive analysis provides a more nuanced understanding of the pressures on penguin populations. It reveals that extreme climate events are not evenly distributed across the Southern Hemisphere, meaning that some penguin populations are in much more immediate danger than others. This new framework can help conservationists prioritize their efforts and resources on the most vulnerable species and habitats. The research also lays the groundwork for assessing how other Southern Hemisphere species may be vulnerable to the cumulative impacts of climate change.
Species on the Front Lines
The study pinpoints several penguin species as facing the highest cumulative risk from climate extremes: African, Snares, Emperor, Adélie, and Galápagos penguins. These species are already under pressure from a variety of threats, including shifting food webs and habitat loss. The added burden of more intense, frequent, and prolonged climate extremes could push these populations to the brink.
Emperor and Adélie Penguins
Emperor and Adélie penguins are particularly vulnerable to changes in sea ice. They rely on stable sea ice for breeding, resting, and molting. As global temperatures rise, the sea ice that serves as their nesting and feeding grounds is diminishing. A 2°C increase in global temperatures could lead to the decline or disappearance of 50% of Emperor penguin colonies and 75% of Adélie penguin colonies. For Emperor penguins, the sea ice is also a crucial nursery for their chicks. If the ice melts too early in the season, chicks that have not yet grown their waterproof feathers can be forced into the ocean, where they may drown. One colony recently experienced the loss of every chick for three consecutive seasons due to early ice melt.
Galápagos Penguins
The Galápagos penguin, the most northerly of all penguin species, is highly endangered, with only about 600 pairs remaining. These penguins are especially susceptible to El Niño events, which can warm the surrounding ocean and disrupt the food chain. In two severe El Niño events, 75% of the Galápagos penguin population died from starvation in each event. The species has never fully recovered from these losses, and with climate change increasing the severity and frequency of El Niño, the future of the Galápagos penguin is uncertain.
Land and Sea Impacts
Penguins are affected by climate change both on land and at sea. On land, their breeding grounds are threatened by rising temperatures and increased precipitation. In Antarctica, the Antarctic Peninsula is warming faster than any other place in the Southern Hemisphere, with average temperatures having risen by 5.5 degrees Fahrenheit over the last 50 years. This has led to an increase in rain, which can be deadly for penguin chicks that are not yet waterproof. In one Adélie penguin colony, heavy rains followed by freezing temperatures resulted in the survival of only two chicks out of 80,000 born in two recent seasons.
At sea, penguins face the challenge of finding food in a rapidly changing environment. The melting of sea ice not only affects their breeding grounds but also their ability to forage for food. The fragmentation of sea ice can create giant icebergs that block access to their usual feeding areas, forcing them to travel farther to find food. This increased effort can lead to exhaustion and starvation, particularly for chick-rearing penguins that need to return to the colony to feed their young.
The Ripple Effect on the Food Web
The impact of climate change on penguins is not just a direct result of extreme weather events but also an indirect consequence of the disruption to the marine food web. Many penguin species, particularly those in Antarctica, rely heavily on krill as their primary food source. Krill, in turn, feed on phytoplankton that grows on the underside of sea ice. As the sea ice melts, the krill population is also affected, leading to a reduction in the amount of food available for penguins.
Penguins are also competing with large-scale commercial krill fisheries, which have drastically reduced the krill population in some areas. This combination of climate change-induced food scarcity and competition from fisheries puts immense pressure on penguin populations. The decline in krill availability can lead to widespread starvation and breeding failure, further threatening the survival of these iconic birds.
A Call for Proactive Conservation
The findings of this new research underscore the urgent need for a more proactive and spatially informed approach to penguin conservation. By identifying the species and regions most at risk, the study provides a roadmap for conservationists and policymakers to target their efforts where they are most needed. This could include creating marine protected areas, implementing stricter fishing regulations, and developing strategies to mitigate the impacts of climate change on penguin habitats.
The message from the scientific community is clear: penguins and their ecosystems cannot afford to wait. As cumulative climate events intensify, targeted, adaptive conservation measures will be key to ensuring that penguins—and the oceans they depend on—have a future. This will require international cooperation and a commitment to reducing greenhouse gas emissions to limit the extent of future climate change.
Looking Ahead: A Future of Uncertainty
The long-term outlook for many penguin species is uncertain. With climate models projecting more intense, frequent, and prolonged climate extremes in the coming decades, the pressures on penguin populations are only expected to increase. Some species could face extinction within our lifetimes if significant action is not taken to address the root causes of climate change. The fate of penguins is inextricably linked to the health of the Southern Ocean and the global climate system. Their survival depends on our ability to create a more sustainable future for our planet.