Coral reefs face extinction; climate impact worsens
Already, 84% of coral reefs are affected by bleaching. Scientists warn that the extinction of these organisms will have consequences, such as decreased biodiversity. Their disappearance may reduce the ocean's ability to absorb CO₂, accelerating climate change.
Coral reefs are already over 84% affected by bleaching, which is caused by thermal stress. This dire condition, driven by human activity, may lead to the mass extinction of these crucial ecosystems on Earth.
The current level of coral reef bleaching is alarming and unprecedented. In 2024, NOAA (National Oceanic and Atmospheric Administration) announced the fourth global mass coral bleaching event in history, following those in 1998, 2010, and 2015-2017.
Climate warming is lethal for ecosystems
According to Science Alert, corals are suffering from thermal stress due to rising ocean temperatures. Reefs expel algae that serve as their food, thus losing their characteristic colors. NOAA reports that conditions in some regions are so extreme they may lead to the nearly complete death of the reefs. Melanie McField, from the Healthy Reefs for Healthy People initiative, emphasizes that even more resilient corals are starting to die.
As a result of thermal stress, corals expel symbiotic algae called zooxanthellae. These microscopic algae provide corals with most of their energy through photosynthesis and give them color. When water temperature rises even by just 1–2°C (2–4°F) above normal, the algae begin to malfunction, forcing the coral to expel them. Consequently, the coral's tissue becomes transparent, exposing the white limestone skeleton beneath. If conditions do not improve, the coral is deprived of its energy source and dies.
Coral reefs are crucial for marine life and millions of people living in coastal communities. In developing regions, many communities rely on coral reefs for food, jobs, and security. Since the 1950s, climate change and environmental destruction have reduced live coral cover by half. With a warming of about 1.5°C (2.7°F), 70-90% of reefs may disappear, proving disastrous for both people and the planet.
The impact of fossil fuel emissions on coral death
Coral reefs are home to about 25% of all marine species. Their disappearance means the death or migration of many organisms. Oceans store 90% of the excess heat caused by burning fossil fuels. Climate warming is progressing rapidly and is one of the most visible effects of human activity on Earth, with the average global temperature already rising by more than 1.1°C (2°F) compared to the pre-industrial era.
