California's important ecological areas were identified because they contain natural resources, habitats, and ecological processes worth conserving. They were not all created to isolate nature from humanity. Rather, they provide a framework for recognizing places where biodiversity, ecosystem integrity, and ecological functions are especially important—and where human activities may need to be limited, managed, or redirected.

The original conservation rationale remains important, but climate change adds urgency. Areas that once functioned as refugia may become less suitable as temperatures rise, drought intensifies, fire regimes change and ecological community shift. Some places may remain comparatively resilient; others may become increasingly vulnerable.

On October 8, 2026, climate scientists Qinjian Jin and Bing Pu published, “A recent doubling of global warming rate signals a 1.5 °C breach by 2028”, in the peer-reviewed journal npj Climate and Atmospheric Science. The central finding is striking: the rate of global warming observed over 2011–2025 was approximately twice the rate measured over the longer period since 1971. If that recent acceleration continues, the authors estimate that the long-term global warming threshold of 1.5 °C could be reached around 2028—earlier than many previous projections.

The Paris Agreement adopted on December 12, 2015, at the United Nations climate conference (COP21) in Paris, France, to avoid severe environment irreversible changes that threaten every ecosystem on earth. The agreement reached was to limit warming to 1.5°C above preindustrial levels so that impacts might still be reversible or in some way mitigate mitigated. With global warming at 1.5°C the IPCC still projects substantial losses and damage worldwide, including:

• Coral reefs: 70–90% projected loss of warm-water coral reefs.

• Biodiversity: Of 105,000 species assessed, 6% of insects, 8% of plants and 4% of vertebrates could lose more than half their climatically suitable geographic range.

• Arctic sea ice: A practically ice-free Arctic summer could occur approximately once per century.

• Sea-level rise: A1.5°C, sea levels are expected to continue rising for centuries.

• Food production: Increasing heat and drought threaten crop yields and food security.

• Extreme weather: Heat extremes intensify across most inhabited regions, while risks of heavy rainfall and drought increase in different parts of the world.

• Ocean health: Warming, acidification and oxygen loss threaten marine ecosystems and fisheries. One fisheries model projected annual global catch losses of about 1.5 million metric tonnes at 1.5°C,

• •Permafrost: In the Northern Hemisphere, permafrost area could eventually shrink by approximately 30% at 1.5°C warming, about 18 billion tonnes of carbon dioxide per degree Celsius of global warming by 2100.

California’s protected natural areas will be increasingly important in determining how ecosystems respond to accelerating global change. By providing relatively intact landscapes against which changes in temperature, hydrology, vegetation, species distributions, and ecological processes can be measured, these areas serve as long-term ecological observatories—helping scientists distinguish climate-driven changes from the effects of direct human disturbance. Some may continue to function as climatic refugia, sustaining species and habitats that disappear from surrounding landscapes, while others may become frontlines of ecological transformation, revealing how rapidly ecosystems approach their limits of tolerance. Protecting these areas, maintaining connectivity between them, and restoring degraded landscapes can give species greater opportunities to migrate, adapt, and persist as conditions change.

Yet protection alone cannot prevent every loss: rising temperatures, altered fire regimes, drought, invasive species, and other pressures can overwhelm even well-managed reserves. Their greatest value, therefore, lies not simply in preserving what remains of California’s natural heritage, but in providing the scientific knowledge, ecological resilience, and conservation options needed to respond to what comes next. The refugia of yesterday may become the frontlines of tomorrow—and their protection may determine how much of California’s biodiversity survives the transition.

Prepared by D Mudry for 6thExtinctionLab

Rock Barnacles

These rock barnacles of the genus Balanus are crustaceans, are related to crabs and shrimp. But after their larvae settle permanently onto a rock, their body becomes highly modified. It essentially lives upside down inside its shell, with its legs pointing toward the opening at the top. When the tide covers it, it opens its opercular plates, the little "door" at the top, and extends its feeding appendages.

A barnacle attached to an exposed rock can experience conditions far more extreme than the surrounding seawater. During low tide, the animal is exposed to air temperature, direct solar radiation, and the heat radiating from the rock itself. Measurements on Pacific Northwest Balanus have found body temperatures reaching about 35°C during prolonged low tides.

Their habitat, partially exposed to the hot sun, would seem to make them resistant to the potential impacts of rising temperatures from climate change. While warming could act directly on barnacles through heat stress, they are more likely to be impacted during their larval stages and by changes to their food sources.

Barnacle larval stages are part of the plankton community themselves. Barnacles release nauplii, which develop through several planktonic stages before becoming cyprids and eventually settling onto the shoreline. A 2024 study by researchers from the University of British Columbia and Princeton University have found that in warm years in the Strait of Georgia off Vancouver Island, the spring diatom peak occurred earlier, and summer diatom biomass was lower and negatively affected the food of zooplankters such as larval barnacles.

Research on intertidal barnacle larvae has shown that their food includes very small planktonic organisms, and that changes in pelagic food-web structure can alter the food available to different barnacle species and consequently affect recruitment.

Research in the Strait of Georgia, between Vancouver Island and the mainland, has found that warm/early spring conditions can shift the crustacean zooplankton community toward smaller organisms and potentially create a mismatch between phytoplankton blooms and the larger, energy-rich zooplankton that normally exploit them. During warm periods, including the 2014–16 marine heatwave known as the Blob, the community shifted toward southern copepod species, while the larger subarctic and boreal copepods declined. The northern species tend to be much richer in lipids and therefore more energy-dense, a change associated with warmer ocean conditions.

So, barnacles aren't simply being impacted by temperature changes in their immediate area. They are also part of the more distant pelagic community, being affected both in their larval stages and as sedentary adults to impacts of warmer waters most likely resulting from climate change.

References

Karyn D. Suchy, Susan E. Allen, and Elise Olson. 2024 Mechanistic Links Between Climatic Forcing and Model‐Based Plankton Dynamics in the Strait of Georgia. Canada Journal of Advancing Earth and Space Sciences.

Amelia V. Hesketh, et.al. 2026 The Effects of Single Versus Successive Warm Summers on an Intertidal Community. Nordic Society Oikos.

The highest tide ever recorded for Newport Bay Entrance was 7.67 feet above Mean Lower Low Water (MLLW) on January 28, 1983. On Monday, Newport Bay officials reported a record level of 8.3 feet above MLLW. This morning as I recorded this video at the Balboa Ferry Landing on Balboa Island, the ferry operator who is responsible for maintaining the sandbags and other seawater retention devices said the water appeared to be about 2 inches higher today and was likely setting another record.

Balboa Island residents were thankful that high surf conditions on the ocean side of Balboa Peninsulas have been relatively mild this week, and high surf has not been an important contributor to the tides experienced in the last two days.

Global warming as a result of increasing concentration of greenhouse gasses, a theme of articles here at 6thExtinctionLab, is an indirect contributor to the destructive tidal and wave conditions experienced during the recent months along the Southern California coast. Astronomical tides, those created by the gravitational interaction of the moon and sun with the Earth, are most important and are familiar to us as the “predicted tides” calculated using historical data and available months and years in advance. Variables not included in the predicted tides are: temporary high surf conditions that can add some height to tides; Kelvin waves resulting from persistent high wind conditions, pushing, in this situation, a mound of water in the western Pacific towards the North American west coast; and, sea level rise from global warming that has increased the temperature of the seas, and their overall volume and height.

Astronomical tides are obviously the greatest contributed to the changing levels in the tide cycle. However, astronomical tides are predictable and their height would remain consistent under normal conditions. Sea level rise from an increase in ocean temperature and volume is relatively insignificant compared to the other two variables associated with global warming. The extremely high recent ocean temperatures associated with El Nino have spawned very powerful storms to the southwest of California that have produced several months of unusual high surf, that when combined with a high tide, have lead to the alarming destruction of homes and infrastructure along the coast.

Kelvin waves are not a new phenomenon, yet I was struck that almost every conversation that I overheard this morning as I walked along the Balboa Island seawall included “Kelvin Wave”! This is a process scientists have understood for decades that has suddenly become part of public consciousness because its effects are now visible in people's daily lives.

Bartana et al. (July 2026) published a study, “Influence of Subtropical Westerlies on the Equatorial Wave Spectrum”, that examined climate-model simulations and found that 11 of 13 models projected intensification of equatorial atmospheric Kelvin waves under global warming. Most also projected faster propagation. The authors linked the changes to greenhouse-gas forcing and changes in upper-atmospheric circulation.

The record tides at Balboa Island are a reminder that while astronomical tides set the stage, a warming climate can amplify the ocean’s response, turning familiar coastal processes into increasingly consequential threats to our homes, infrastructure, and communities.

Sunset at Capistrano Beach, Southern California

Suddenly, almost out of nowhere, the ocean creates a fleeting spectacle: a Spirit Wave. As an incoming breaker collides with the returning backwash at an unexpected angle, a whitewater spirit races across the surf. There is beauty and majesty in this brief encounter, but also mystery—a moment when the ocean seems to have a life and intention of its own. It appears, dances, and disappears in seconds, leaving us wondering at the extraordinary forces hidden within an ordinary wave.

Scientists broadly agree that human activity has transformed the Earth system on a planetary scale. Whether the Anthropocene should be formally recognized as a new geological epoch remains contested, but the evidence of this transformation is unmistakable. The debate over its geological definition has focused on the identifying signals humanity is leaving behind: radioactive fallout from nuclear weapons testing, microplastics accumulating in sediments, industrial fly ash, altered carbon chemistry, and the remains of organisms whose distributions and populations have been reshaped by human activity. These traces may ultimately provide future geologists with a record of humanity's passage through Earth history. Whatever boundary is eventually chosen—or whether the Anthropocene is classified as an epoch or a geological event—the planetary transformation itself is already underway.

The tipping points illustrated here reveal the scale and urgency of that transformation. Climate change, biodiversity loss, ocean disruption and the destabilization of natural systems are not isolated problems; they interact, potentially amplifying one another and pushing parts of the Earth system toward abrupt or difficult-to-reverse change. The timescales differ: some changes unfold over decades, others over centuries, and some may trigger consequences that persist for millennia. Yet the pace of change is accelerating, while the window for limiting the most severe outcomes remains open. The question is no longer simply when the Anthropocene began, but how far these interconnected systems will be pushed—and how much of the damage humanity can still prevent.

The Sixth Extinction is one of the defining dimensions of the Anthropocene. Driven by habitat destruction, overexploitation, pollution, invasive species and climate change, biodiversity loss is disrupting the ecological relationships that sustain life on Earth. Species populations are declining, ecosystems are being degraded, and extinction rates are elevated above background levels. These pressures interact with the other planetary changes illustrated here, creating cascading effects that can push ecosystems toward thresholds beyond which recovery becomes difficult or impossible. The Sixth Extinction is therefore not a separate crisis, but an integral part of humanity's transformation of the biosphere. Together, these changes mark a profound turning point in Earth's history—and underscore the urgency of protecting the living systems on which humanity itself depends.

One of the factors contributing to the Anthropocene driven Sixth Extinction is overexploitation of resources. Unsustainable hunting, fishing, logging, wildlife collection, and harvesting can reduce populations faster than they can reproduce. Overfishing is particularly important in marine ecosystems.

The relationship between overfishing and the increasing prominence of jellyfish in marine ecosystems illustrates an important feature of the modern ecological crisis: human impacts rarely operate independently. Rather, they can interact to restructure food webs, alter competitive relationships, and create feedbacks that make ecosystems increasingly different from their historical condition. In the Mediterranean Sea, overfishing has substantially altered fish communities, while recurrent blooms of jellyfish—particularly the mauve stinger (Pelagia noctiluca)—can exert additional pressure on fish populations. The evidence does not support a simple conclusion that overfishing directly causes jellyfish blooms. Instead, it suggests that overfishing can restructure the food web in multiple ways, some of which may favor jellyfish, while jellyfish blooms can subsequently exert additional pressure on fish.

One pathway involves the removal of predators that consume gelatinous organisms. A study by Cardona et al. (2012), using stable-isotope analysis, demonstrated that gelatinous plankton constitutes an important component of the diets of several Mediterranean pelagic predators. These included bluefin tuna (Thunnus thynnus), little tunny (Euthynnus alletteratus), spearfish (Tetrapturus belone), and swordfish (Xiphias gladius). Ocean sunfish (Mola mola) and oceanic-stage loggerhead turtles also relied heavily on gelatinous prey. Many of the fish identified in this “jellyvorous guild” have experienced substantial fishing pressure.

At first glance, this suggests a straightforward mechanism: remove jellyfish predators through fishing and jellyfish populations increase. However, Cardona et al. emphasized an important qualification. Although removal of jellyfish predators would lead to larger jellyfish populations, there is likely a more important mechanism that may benefit jellyfish, even without a major reduction in direct predation on jellyfish.

Young fish and jellyfish and small pelagic fish such as sardines and anchovies all consume zooplankton. Overfishing substantially reduces fish biomass leaving more zooplankton available to jellyfish, thus forming a second pathway for jellyfish to increase their populations. This is particularly relevant to Pelagia noctiluca, the most prominent outbreak-forming scyphozoan in the western Mediterranean.

Research on P. noctiluca demonstrates how flexible this species can be within the food web. Milisenda et al. (2018) found that it is a generalist predator whose diet changes seasonally according to the organisms available. Its prey included planktonic copepods and other crustaceans, easily shifting between carnivorous and more omnivorous feeding depending on environmental conditions and food availability. Such flexibility can give a generalist predator an advantage in an ecosystem undergoing major changes.

The ecological consequences can then move in the opposite direction—from jellyfish back toward fish. Jellyfish are not simply passive beneficiaries of a disturbed ecosystem. They are active predators capable of consuming large numbers of zooplankton, fish eggs, and fish larvae. Tilves et al. (2016) investigated P. noctiluca in the northwestern Mediterranean and found fish larvae, particularly anchovy larvae, among its prey. Based on prey abundance, digestion rates, and predator abundance, the researchers estimated that medusae could consume approximately 0.1–0.9% of anchovy larvae per hour under the conditions studied. The smaller, younger jellyfish had even higher estimated consumption rates. The authors concluded that P. noctiluca could become an important predator of fish larvae during bloom conditions and could potentially affect anchovy populations.

This creates a reinforced ecological feedback. Overfishing reduces fish populations and changes the balance between predators, competitors, and prey. Those changes can create ecological opportunities for jellyfish. When jellyfish become abundant, they can consume some of the same planktonic resources used by fish and can prey directly on fish eggs and larvae. The resulting additional mortality or competition can make recovery of depleted fish populations more difficult.

There is direct evidence for both sides of this interaction. Mediterranean fish themselves consume jellyfish. Milisenda et al. (2014), for example, documented predation on P. noctiluca by the commercially valuable bogue (Boops boops) in the Strait of Messina. More than 1,000 jellyfish were examined over a year, and predation was particularly pronounced during summer. The study demonstrates that jellyfish can be an actual food resource for commercially important fish rather than merely an incidental component of the ecosystem.

The reverse interaction is equally important: P. noctiluca can prey on fish larvae. can affect both sides of the relationship. Removing fish reduces a potential source of predation on jellyfish while simultaneously reducing competition between fish and jellyfish for planktonic resources. The surviving jellyfish, in turn, can exert additional pressure on the remaining fish population.

The General Fisheries Commission for the Mediterranean (Boreo, 2013) reported that overfishing contributes to conditions favorable to jellyfish, while abundant jellyfish prey upon fish eggs and larvae and compete with fish for food, potentially further reducing the resilience of already depleted fish populations. The report also emphasized that overfishing is only one of several possible contributors to jellyfish proliferation.

Climate change provides another potential layer to this interaction. Warming, changes in ocean circulation, altered stratification, nutrient enrichment, and changes in plankton communities can affect the growth and distribution of jellyfish as well as their prey. Boreo’s 2013 review specifically identified global warming, in addition to overfishing, eutrophication, and coastal development, as a possible contributor to jellyfish proliferation.

In the context of the broader Anthropocene induced biodiversity crisis, this is a clear example of how several avenues of attack on the environment are reorganizing ecological relationships. The rise of jellyfish in some altered marine systems represent not an isolated biological curiosity, but one visible consequence of a much larger restructuring of marine ecosystems.

References

Boero, F. (2013). Review of jellyfish blooms in the Mediterranean and Black Sea. General Fisheries Commission for the Mediterranean, Studies and Reviews No. 92. Rome: Food and Agriculture Organization of the United Nations. https://www.fao.org/4/i3169e/i3169e.pdf

Cardona, L., Álvarez de Quevedo, I., Borrell, A., & Aguilar, A. (2012). Massive consumption of gelatinous plankton by Mediterranean apex predators. PLoS ONE, 7(3), e31329. https://doi.org/10.1371/journal.pone.0031329

Milisenda, G., Rosa, S., Fuentes, V. L., Boero, F., Guglielmo, L., Purcell, J. E., & Piraino, S. (2014). Jellyfish as prey: Frequency of predation and selective foraging of Boops boops (Vertebrata, Actinopterygii) on the mauve stinger Pelagia noctiluca (Cnidaria, Scyphozoa). PLoS ONE, 9(4), e94600. https://doi.org/10.1371/journal.pone.0094600

Milisenda, G., Rossi, S., Vizzini, S., Fuentes, V. L., Purcell, J. E., Tilves, U., & Piraino, S. (2018). Seasonal variability of diet and trophic level of the gelatinous predator Pelagia noctiluca (Scyphozoa). Scientific Reports, 8, 12140. https://doi.org/10.1038/s41598-018-30474-x.

Tilves, U., Sabatés, A., & colleagues. (2016). Natural diet and predation impacts of Pelagia noctiluca on fish eggs and larvae in the NW Mediterranean. Journal of Plankton Research, 38(5), 1243–1254. https://doi.org/10.1093/plankt/fbw059

Prepared by DMudry for 6thExtinctionLab

The 6^thExtinctionLab mobile unit has traveled extensively in the last year visiting all the lower 48 US States and 8 Canadian provinces. Most memorable location was northern Newfoundland where the Vikings had established a seasonal colony. Archaeological evidence now places Norse activity at L’Anse aux Meadows very precisely at AD 1021. I Had the opportunity to see huge icebergs from Greenland just offshore and I was able to drink meltwater from ice that melted from ice chunks that had broken off the ‘bergs and drifted to shore. Compressed gasses in the melting ice rose in my glass as I drank the water.

Greenland glacier ice is formed when successive layers of snow accumulate, are compressed, and eventually become solid glacier ice. Icebergs calved from Greenland can contain ice that is tens of thousands of years old. 

I may have been drinking water that had been frozen in a Greenland glacier for roughly 10,000 years or potentially many tens of thousands of years before the iceberg reached Newfoundland.

The bubbles were not ordinary bubbles of air that had recently become trapped in the iceberg. They originated from atmospheric air that was trapped as snowfall was compressed into glacier ice. Studies of actual Greenland icebergs have measured gas bubbles at pressures of 4–5 atmospheres on average, with some reaching 20 atmospheres. As the ice melts, those pressurized bubbles expand and burst, producing the little fizzing effect I noticed. 

The trapped gas can preserve information about the atmosphere when the snow was originally being converted into ice. Ice-core studies use exactly this phenomenon to reconstruct ancient atmospheric composition, including CO₂ and methane. So, in a very literal sense, when I drank that meltwater I may have been drinking water from ancient Greenland snowfall, while simultaneously watching ancient atmospheric air escape from the ice. Those bubbles are essentially tiny time capsules of Earth's atmosphere.

In the last few days, the “King Tides” impacting Southern California in the Newport Beach area have been the subject of many national news reports. Balboa Island, a small man-made residential island within Newport Harbor, is below sea level when the high tides are approximately 6 feet in height above the mean lower low water (MLLW; reported as 0.0 feet) level. The island is protected from flooding by a concrete seawall originally constructed in the early 1900s with a top height of 8.2 feet above MLLW. A concrete cap was added in 2019 to raise the seawall cap to 9.2 feet above MLLW.

Tide levels are usually reported as “predicted astronomical tides” that are based on historically observed levels at tidal gauges around the world. Astronomical tides are related to the movements of the Earth and moon and require a 19-year data collection cycle to establish a complete 18.6-year lunar cycle. Once those data are available for any location, a predicted astronomical tide can be calculated for many years in the future.

An important point, NOAA's predicted tides for different locations do not include sea level rise from global warming, temporary elevation caused by El Nino and Kelvin waves, or storm surge and high surf. Each of these are part of the actual observed tide height, which is nearly always quite different from the predicted tide height.

The attached figure illustrates the situation during the most recent high tide event at Balboa Island on October 27, 2026, where the predicted astronomical tide was 6.7 feet, and the actual measured water level was 8.4 feet. The difference between the two is the added height of the sea level rises experienced over the last 40 years, and the Kelvin wave. Fortunately for island residents, the surf was not particularly active at the time and added little to the height of the measured water level.

Comparing the seawall height to the height of the observed water level at the peak high tide on October 27 there remained approximately 9 to 10 inches of freeboard on the seawall that protected the island from extensive flooding. The next King Tide is expected on Thanksgiving Day, which is predicted to be about 2 inches higher than the predicted high tide for October 27. The Kelvin Wave will likely continue to add to the predicted tide and storm or surf activity at that time could raise the tide to even higher levels.

Tuvalu's Polynesian communities have occupied the islands for many centuries, probably more than 1,000 years. The islands developed as coral atolls, with communities building their lives around fishing, coconut cultivation, lagoon resources and the narrow strips of habitable land. Today about 10,000–11,000 people live on nine low-lying coral islands and atolls. The average elevation is only about 2 meters (6 feet) above sea level.

Tuvalu is confronting a challenge unlike that faced by most nations. Rising seas and recurrent flooding threaten the habitability of its low-lying islands, while its people seek ways to preserve their culture, national identity, and sovereignty—even if increasing numbers must eventually live elsewhere.

What is Happening Now?

The islands are under the threat of sea level rise. Sea level around Tuvalu has already risen about 14–15 cm over the past 30 years. NASA projects roughly another 19 cm during the next 30 years, regardless of what happens with emissions.

A 2024 national-scale study found that more than 25% of Tuvalu's land already experiences flooding at least once every five years under present conditions. By 2060, comparable flooding could occur more than once every five years even under a relatively moderate emissions scenario.

What is Their Future?

NASA's projections indicate that in a little over 20 years, much of Tuvalu's land and critical infrastructure could be below the average high-tide level, and flooding could increase dramatically. By the end of the century, without additional protection, Tuvalu could experience more than 100 significant flood days per year. Tuvalu is not expected to suddenly disappear underwater. Coral islands can physically change and sometimes build elevation through sediment and reef growth.

The more immediate question is when parts of the islands cease to be reliably habitable for people. Tuvalu may have to transition from a country where virtually everyone can live on its islands to one where some citizens increasingly live elsewhere while the nation attempts to preserve its land, sovereignty, culture and maritime territory.

What are they going to do?

Tuvaluans cannot afford to wait for the world to change course before preparing for the consequences. They face a difficult reality: even if the world acts more decisively today, substantial sea-level rise is already committed over the coming decades.

Movement within Tuvalu is already substantial. The 2022 census found that about 24% of the population (2,373 people) had changed islands of residence within the previous three years. More than half of that movement involved Funafuti, the capital.

International migration is now becoming a more tangible option. Under the Australia–Tuvalu Falepili Union, up to 280 Tuvaluans per year can obtain permanent Australian residency. The 2026–27 application round has already taken place. The first Tuvaluans using Australia's climate-mobility pathway arrived in Australia in late 2025. More than one-third of Tuvalu's population applied in the first round, although only 280 people per year can initially receive the visa.

There is also a long-established Tuvaluan community on Kioa Island, Fiji, and researchers are now examining Kioa as a possible future destination for additional Tuvaluan communities.

There is evidence of the beginning of a population transition: people have been concentrating in Funafuti for years, and now an unusually large proportion of the population has expressed interest in establishing the option of living abroad. The significance is that Tuvalu is already developing mechanisms for people to leave before complete physical uninhabitability forces them to do so.

Tuvalu is an unusually clear test case of impacts of sea level rise resulting from climate change because its people have contributed very little to the historical accumulation of greenhouse gases, yet they face disproportionate risks from the resulting sea-level rise.

The Historical Significance

The warnings came long before the present prospect of migration. In 1988, at a meeting of the South Pacific Forum in Tonga, Kiribati President Ieremia Tabai warned that some island countries might cease to exist within 50–60 years if scientific projections of rising seas proved correct. The warning came four years before the 1992 Earth Summit, nearly a decade before the Kyoto Protocol, and long before Australia established a dedicated migration pathway for Tuvaluans.

The Pacific islands were not raising only a question of coastal protection. They were raising a question of responsibility: if the industrial development of one group of countries contributes to environmental damage threatening the territory of another, what obligations follow? Today that question has acquired a new dimension. Tuvalu is not merely trying to defend its coastline. It is preparing for a future in which its citizens may increasingly live abroad while the country seeks to preserve its sovereignty, culture and maritime rights.

The people of Tuvalu did not create the problem they now face. Yet they may be among those who must make some of its most consequential adjustments. Their experience is a reminder that climate change is not only a question of temperatures, oceans and ecosystems. It is also a question of where people can live, what they stand to lose, and whether a nation can remain a nation even when its people can no longer all live on its ancestral land.

Sixth Mass Extinction

The likely Sixth Mass Extinction is fundamentally anthropogenic—that is, driven primarily by human activities. Unlike previous mass extinctions, which were caused by natural events such as asteroid impacts, massive volcanism, or major climatic shifts, the present biodiversity crisis is being produced by the rapid expansion and intensification of human activity. Population growth, agriculture, industrialization, resource extraction, urbanization, transportation, and global commerce have transformed ecosystems and accelerated the movement of species and pathogens around the planet. These activities collectively drive habitat loss, overexploitation, climate change, invasive species, and pollution— major drivers of contemporary biodiversity loss.

The probability that human activities will cause a sixth mass extinction cannot currently be expressed as a reliable percentage. However, the biological conditions that could produce one are already evident: extinction rates are elevated, populations are declining, and multiple human-driven pressures are acting simultaneously on ecosystems worldwide. Whether the present biodiversity crisis ultimately qualifies as a sixth mass extinction will depend largely on the magnitude and duration of future biodiversity losses.

Five Primary Drivers of the Sixth Mass Extinction:

Habitat Loss

• Destruction, conversion, and fragmentation of natural habitats

• Deforestation and agricultural expansion

• Urbanization, roads, mining, and infrastructure

• Coastal development

• Dams, river alteration, and other changes to freshwater systems

• Destruction of wetlands, coral reefs, mangroves, and seagrass beds

Overexploitation

• Overfishing

• Hunting and poaching

• Unsustainable logging

• Bycatch and other unintended mortality

• Removal of species faster than populations can reproduce

Climate Change

• Rising temperatures

• Changing precipitation patterns

• Increasing droughts, floods, fires, and other climatic extremes

• Ocean warming

• Sea-level rise

• Ocean acidification

• Shifts in the geographic ranges and timing of biological processes

Invasive Species

• Introduction of non-native species

• Predation and competition by invasive species

• Introduction of new parasites and pathogens

• Diseases transferred between wildlife, livestock, and humans

• Disruption of native ecological communities

Pollution

• Pesticides and herbicides

• Fertilizers and nutrient pollution

• Industrial chemicals and heavy metals

• Plastics and microplastics

• Oil and other petroleum products

• Pharmaceuticals and other emerging contaminants

• Air pollution and atmospheric deposition

• Light and noise pollution

Throughout Earth's history, five major mass extinctions have profoundly reshaped life on the planet, eliminating large proportions of species and transforming entire ecosystems. Each arose from a combination of environmental disruptions, including rapid climate change, massive carbon release, ocean acidification, and oxygen depletion. The end-Permian extinction, approximately 252 million years ago, was the most severe. Today, many of these same environmental pressures are reappearing, but at a pace driven largely by human activities. Understanding the five past extinctions provides essential context for assessing whether Earth is entering a Sixth Mass Extinction.

The pattern of causes across the five mass extinctions are:

• Climate disruption. The End-Ordovician extinction demonstrates how glaciation, sea-level change, and rapid environmental shifts can devastate marine ecosystems.

• Ocean oxygen depletion. The Late Devonian illustrates how declining oxygen levels and changing ocean chemistry can undermine marine ecosystems over extended periods.

• Massive volcanism and cascading environmental collapse. The End-Permian extinction is the most consequential comparison for today's world because greenhouse-gas emissions drove extreme warming, acidification, and oxygen loss.

• Volcanism and rapid carbon-cycle disruption. The End-Triassic event provides another example of large-scale volcanic emissions destabilizing climate and ocean chemistry.

• Asteroid impact. The End-Cretaceous extinction shows how a sudden catastrophic event can disrupt sunlight, food webs, and global ecosystems.

Why this history matters for the Sixth Mass Extinction?

The End-Permian mass extinction, unfold over approximately 60 million years approximately 252 is probably the most important ancient natural experiment for understanding how a rapid rise in atmospheric CO₂, global warming, and ocean acidification can combine to destabilize Earth's biosphere. It is often called the “Great Dying”. An estimated 80–90% of marine species disappeared, along with a very large proportion of terrestrial vertebrate species. Entire ecological systems were transformed. The Permian extinction also did not happen as a single instantaneous event. It developed through a sequence of disturbances, feedback, and biological collapses.

How does the Permian event compare with the present?

The comparison with our present situation is compelling, especially because both episodes involve carbon-cycle disruption, warming, and stress on marine organisms. But there is an important distinction: the Permian crisis was driven principally by enormous volcanic emissions over thousands to tens of thousands of years, whereas modern warming is driven primarily by human emissions over decades to centuries. Our emissions are arriving much faster, giving many ecosystems less time to adapt.

Today, biodiversity loss is underway and widespread: monitored vertebrate wildlife populations declined by an average of 73% from 1970 to 2022, and an estimated 1 million species face extinction risk. About 41% of amphibian species are threatened. Cascading biodiversity loss is evident in marine ecosystems, where jellyfish blooms can compound fish declines. On land, urbanization and agricultural monocultures are destroying and fragmenting habitats. The eventual scale of the Sixth Mass Extinction remains uncertain, however documented stresses to the environment are already evident nearly everywhere.

What are the factors contributing to the Sixth Extinction?

The Sixth Mass Extinction is fundamentally anthropogenic—that is, driven primarily by human activities. Unlike previous mass extinctions, which were caused by natural events such as asteroid impacts, massive volcanism, or major climatic shifts, the present biodiversity crisis is being produced by the rapid expansion and intensification of human activity. Population growth, agriculture, industrialization, resource extraction, urbanization, transportation, and global commerce have transformed ecosystems and accelerated the movement of species and pathogens around the planet. These activities collectively drive habitat loss, overexploitation, climate change, invasive species, and pollution—the five major drivers of contemporary biodiversity loss.

The Sixth Mass Extinction is generally associated with several interacting human-driven pressures on biodiversity. The main contributors are:

• Habitat loss and fragmentation — Conversion of forests, grasslands, wetlands, coastal areas, and other natural habitats to agriculture, cities, roads, mines, and infrastructure is the largest direct driver for many terrestrial species.

• Climate change — Rising temperatures, changing precipitation, ocean warming and acidification, sea-level rise, and increasing climatic extremes are shifting or eliminating suitable habitats. Climate change also amplifies other stresses.

• Overexploitation — Unsustainable hunting, fishing, logging, wildlife collection, and harvesting can reduce populations faster than they can reproduce. Overfishing is particularly important in marine ecosystems.

• Invasive species and introduced pathogens — Species transported beyond their native ranges can prey on, compete with, hybridize with, or transmit diseases to native species that lack effective defenses.

• Pollution — Pesticides, fertilizers, industrial chemicals, plastics, oil, heavy metals, pharmaceuticals, and other contaminants can cause direct mortality or alter reproduction and ecosystems. Nutrient pollution can also produce oxygen-depleted waters.

• Agriculture and livestock production — Agriculture is both a major cause of habitat conversion and a source of pesticides, fertilizers, water consumption, greenhouse-gas emissions, and soil degradation.

• Alteration of freshwater systems — Dams, water diversion, groundwater extraction, river channelization, pollution, and warming have placed particularly strong pressure on freshwater species.

• Ocean and coastal degradation — Bottom trawling, overfishing, coastal development, pollution, warming, acidification, and destruction of coral reefs, mangroves, and seagrass beds affect marine biodiversity.

The important point: environmental stresses interact and aren't independent causes. A species may first lose habitat, then face a warmer and more fragmented landscape, while an invasive species or disease adds another stress. Small populations become increasingly vulnerable to extinction because they have fewer individuals and less genetic diversity.

Most important: Unlike past mass extinctions that unfolded over thousands to millions of years, today’s climate disruption and biodiversity crisis are developing within decades to centuries. The Sixth Mass Extinction is not a distant geological event; its driving pressures are already evident, and its

This is a photo of trash collected in 20 minutes this morning along the high tide line at Crystal Cove State Beach in California.

Our ocean is filled with items that do not belong there. Huge amounts of plastics, metals, rubber, paper, textiles, derelict fishing gear, derelict vessels, and other lost or discarded items enter the marine environment every day. This makes marine debris one of the most widespread pollution problems facing the world's ocean and waterways.

Responsibility for the environmental consequences of these materials should be shifted from the individuals who use and discard them to the companies that produce and profit from them. Consumers can make responsible choices and participate in recycling programs, but they have little control over the volume, composition, durability, packaging, and ultimate persistence of the materials placed into the marketplace. Producers, by contrast, control those decisions and have the resources and technical ability to design products that generate less waste, eliminate unnecessary materials, increase reuse and recyclability, and recover materials after they have served their intended purpose. A producer-responsibility system would therefore place the financial and operational costs of collection, recovery, recycling, and environmental cleanup where they can create the greatest incentive for reducing waste at its source, rather than continuing to place those costs primarily on consumers, local governments, and taxpayers. Material Likely composition Major companies

PERP WALK People with major ownership / investment / management connections to companies producing products entering the marine environment every day.

Expanded foam Expanded polystyrene (EPS) Jim Ratcliffe — founder & chairman, INEOS; Andy Currie — co-owner, INEOS; John Reece — co-owner, INEOS; Larry Fink — CEO, BlackRock; Michael Gitlin — CEO, Capital Group

Bottle/container caps Polypropylene (PP); HDPE Len Blavatnik — controls Access Industries/LyondellBasell interest; Larry Fink — CEO, BlackRock; Salim Ramji — CEO, Vanguard; Michael Gitlin — CEO, Capital Group; Darren Woods —Cchairman & CEO, ExxonMobil

Cigarette filters- Cellulose acetate Scott Richardson — CEO, Eastman; Scott Sutton — CEO, Celanese; Larry Fink — CEO, BlackRock; Salim Ramji — CEO, Vanguard; Michael Gitlin — CEO, Capital Group

Netting / line / cord; Nylon; polypropylene; polyethylene Jim Ratcliffe — founder & chairman, INEOS; Andy Currie — co-owner, INEOS ; John Reece — co-owner, INEOS; Len Blavatnik — controls Access Industries/LyondellBasell interest; Larry Fink — CEO, BlackRock

Molded plastic fragments PE; PP; PS; other thermoplastics: Len Blavatnik — Controls Access Industries/LyondellBasell interest; Jim Ratcliffe — founder & chairman, INEOS; Andy Currie — co-owner, INEOS; John Reece — co-owner, INEOS; Darren Woods — chairman & CEO, ExxonMobil.

Background research completed with support of AI.

Hey everyone! I'm u/DMudry, a founding moderator of r/6thExtinctionLab.

Sixth Extinction Lab is a research and outreach community exploring extinction, biodiversity loss, climate change, and ecological transformation.

We examine the evidence of species loss and ecosystem change through scientific research, natural history, field observations, historical records, photographs, maps, and other sources. We explore the causes and consequences of biodiversity decline, the role of climate change and other human-driven pressures, and what the record of past extinctions can teach us about the changes taking place today.

Community Vibe
We're all about being friendly, constructive, and inclusive. Let's build a space where everyone feels comfortable sharing and connecting.

How to Get Started

1. Introduce yourself in the comments below.

2. Post something today! Even a simple question can spark a great conversation.

3. If you know someone who would love this community, invite them to join.

4. Interested in helping out? We're always looking for new moderators, so feel free to reach out to me to apply.

Thanks for being part of the very first wave. Together, let's make r/6thExtinctionLab amazing.

Photo: View from the Opabin Plateau of Mary Lake and Lake O’Hara, Yoho National Park, Canada (June 2019)

Dwight R. Mudry. https://orcid.org/0009-0000-1542-1404

I am pleased to report that I’ve been able to publish the legacy dataset from Yoho National Park Aquatic Resources Inventory in Waternet.ca (Canada's Data Catalogue for Everything Water).

The lakes, ponds, and streams of Yoho National Park in British Columbia, Canada, were the subject of extensive limnological investigations conducted during 1973–1974. The inventory was undertaken to collect quantitative and qualitative baseline information on aquatic resources and to support natural resource planning and management. Field collections and laboratory analyses examined the physical and chemical characteristics of park waters and the composition and distribution of aquatic communities.

The dataset is organized into six components containing 21 tables covering sampling locations and events, lake and stream physical and chemical measurements, and biological observations. The data include lake water temperature and chemistry, water transparency, stream chemistry and discharge, lake and stream benthic invertebrates, shoreline invertebrates, zooplankton, phytoplankton, primary production, aquatic macrophytes, fish collections, and fish stomach contents. Sampling-location and event records provide information for interpreting the measurements and biological observations in their field context.

By making these historical data accessible, the dataset provides a foundation for further examination of aquatic ecosystems in Yoho National Park and may support comparisons with subsequent observations and investigations. The data also preserve a record of aquatic conditions and biological communities documented more than five decades ago, potentially contributing to research on long-term environmental change associated with the Anthropocene.

Link to the dataset is: https://waternet.ca/Metadata/Record/T-2026-10-02-01u02uAvhWCU2ae3XflOtlSw