Coral Reefs Are Shifting Toward the Poles, But Still Face Climate Threats
Blue Economy Insights – June 2025
A groundbreaking new study from the University of Hawaiʻi’s Institute of Marine Biology (HIMB) reveals that coral reefs are slowly expanding toward the poles as global ocean temperatures rise. Published June 9th, 2025 in Science Advances, the study offers a clear message: while poleward migration of coral reefs is real, only immediate and ambitious cuts in greenhouse gas emissions can meaningfully protect these ecosystems from widespread collapse.
A Slow March North and South
“As the ocean warms, species tend to move poleward,” explains Dr. Noam Vogt-Vincent, NOAA Climate & Global Change Postdoctoral Fellow and lead author of the study. “Coral reefs have done this in past periods of climate change, but the timeline was unclear. We now know it takes centuries.”
Using the University of Hawaiʻi’s Koa supercomputer, the research team modeled the distribution and evolution of coral reefs across roughly 50,000 global sites. Their simulations accounted for coral growth, dispersal, evolutionary adaptation, and response to heat stress, all crucial to coral survival.
They ran scenarios across three climate futures:
- Low warming (~2°C by 2100)
- Moderate warming (~3°C)
- High warming (>4°C)
A Bleak Forecast Without Action
The results were sobering. Even under moderate warming scenarios, the expansion of tropical coral reefs into cooler, higher-latitude waters , such as northern Florida, southern Australia, and southern Japan, would take centuries. Meanwhile, the most significant coral losses are expected within the next 50 years.
“It was previously thought that higher-latitude reefs could act as refuges,” says Dr. Vogt-Vincent. “But while reef migration does occur, it is far too slow to save tropical coral ecosystems this century.”
Hope Is Not Lost
Despite the grim projections, the study also highlights a powerful counterpoint: if global emissions are reduced sharply and quickly, coral reef loss can be dramatically limited. Under a low-emissions scenario aligned with the Paris Climate Agreement, global coral reef loss could be reduced from an estimated 70% to around 30%.
“Our findings show coral reefs are not a lost cause,” says Dr. Vogt-Vincent. “Immediate reductions in greenhouse gas emissions will have enduring benefits, not just for the next few decades, but for centuries to come.”
Looking Ahead: Modeling the Future
The Marine Ecological Theory Lab at HIMB is continuing to develop high-resolution simulations to better understand coral reef futures. Upcoming research will explore how genetic traits influence coral larval dispersal and whether naturally cooler reef microclimates could offer short-term refuges in a warming world.
“I find it exciting to forecast what our oceans might look like decades or even centuries from now,” says Dr. Vogt-Vincent. “This study shows that while time is short, meaningful action is still possible.”
As climate challenges mount, this research underscores a vital truth, the fate of coral reefs is still in human hands.
Key Stats from the Study:
- Coral reef range shifts take centuries, not decades
- Without emissions cuts, 70% of coral reefs could be lost
- With strong emissions reductions, losses could be limited to ~30%
- Climate action this century will influence reef health for the next 1,000 years
Tags: coral reef migration, climate change, marine biodiversity, supercomputer simulations, greenhouse gas emissions, ocean science, HIMB, global reef outlook, coral adaptation, blue economy
