Geological changes occur too slowly for human notice but reshape the planet entirely across immense stretches of time. Focusing on the next 250 million years provides a snapshot of this deep time, representing the likely endpoint of the current supercontinent cycle. Predictions for this distant future are based on current, measurable rates of continental drift and established models of plate tectonic processes, which project the dispersed continents will coalesce once more into a single entity.
The Formation of Pangea Ultima
The Earth’s next supercontinent, often referred to as Pangea Ultima, is predicted to assemble within the next 250 million years. This massive landmass will form as a consequence of the ongoing movement of tectonic plates, driven by the closure of both the Atlantic and Indian Oceans. The Atlantic Ocean, currently expanding, is expected to reverse its spreading as new subduction zones form along its margins, pulling the seafloor back into the mantle.
Africa will continue its northward drift, completely eliminating the Mediterranean Sea and causing a massive mountain-building event as it crashes into Europe. North America will rotate and collide with the northern coast of Africa. South America will wrap around the southern tip of the landmass, while Australia, the fastest-moving continent, merges with Asia. The resulting Pangea Ultima will be a colossal, ring-shaped supercontinent, encircling an inland sea that is the remnant of the former Atlantic and Indian Oceans.
The colossal Pacific Ocean, by contrast, will have grown even larger, becoming the single global ocean, sometimes called Panthalassa. This new landmass will feature immense, rugged mountain ranges created by the continental collisions, far exceeding the scale of the present-day Himalayas. The shape and size of this single continent will drastically alter the planet’s geography, setting the stage for radical environmental changes.
Environmental Extremes and Weather Patterns
The formation of a single supercontinent will fundamentally reorganize Earth’s climate and weather systems. With the landmass consolidated, the vast interior regions will be cut off from oceanic influence, leading to the creation of immense, hyper-arid deserts. Climate models predict that summer temperatures in the heart of this supercontinent could regularly soar into the range of 50°C to 65°C, leaving the bulk of the landmass parched.
The extreme tectonic activity involved in the continental collisions is expected to trigger increased volcanism. This surge in volcanic eruptions will pump massive amounts of carbon dioxide into the atmosphere, potentially doubling the atmospheric concentration to levels around 1,120 parts per million. This greenhouse effect, combined with the natural aging of the Sun which will be shining about 2.5% brighter, will contribute to a globally hotter planet. The centralization of landmasses will also severely disrupt the flow of global ocean currents, leading to more volatile and extreme temperature differences between seasons and regions.
The supercontinent cycle is also linked to changes in global sea level, primarily through its effect on seafloor spreading rates. The reassembly of continents into Pangea Ultima is expected to be accompanied by a slowdown in the rate of seafloor spreading. When spreading is slow, the mid-ocean ridges are less elevated, causing the ocean basins to deepen and effectively lowering the global sea level and reducing shallow continental shelf habitats.
The Future of Life on Earth
The radically altered geography and climate will impose severe evolutionary pressures on the planet’s biosphere. The combination of intense heat, extreme aridity, and high atmospheric humidity near the coasts will make the majority of Pangea Ultima inhospitable to many dominant species. Computer models suggest that only a small fraction of the supercontinent—perhaps between 8% and 16%—will remain habitable for mammals. Mammals, including humans and their descendants, are particularly vulnerable because their complex physiology relies on sweating, a mechanism that fails in conditions of high heat and high humidity.
The intense environmental stress is predicted to drive a major mass extinction event, particularly affecting organisms adapted to cooler, more stable conditions. Plants will struggle to survive the heat, as temperatures above 40°C inhibit their growth, and above 60°C, they suffer irreversible damage. This collapse of the plant base will disrupt the entire food chain. The reduced coastal habitats and the closure of oceans will also devastate marine life accustomed to shallow shelf environments.
Life that survives will be highly specialized, favoring species that are drought-resistant, heat-tolerant, or able to thrive in the few remaining temperate zones, such as the polar fringes. Cold-blooded animals, such as reptiles, may be better suited to the new, hotter world, potentially dominating the surviving terrestrial ecosystems. Organisms will need to adapt through rapid evolution, or find refuge in caves, underground, or by becoming nocturnal to escape the most intense daytime heat.