Marine scientists predict the oceans' coral reefs could die in 50 to 75 years. Their study in the journal , based on years of observation, blames the combination of two factors for threatening the largest living structures on earth.
Mark Eakin is the coordinator of for the U.S. National Oceanic and Atmospheric Administration, called NOAA. "We believe about a two degree increase celsius, greater than what we have seen over the last 100 years, will be a critical level for coral reefs. In addition the increase in atmospheric CO2 [carbon dioxide] not only causes an increase in temperatures but it also changes the chemistry of the oceans. It drops the pH [measure of acidity and alkalinity] and makes the ocean more acidic," he said.
Seventeen marine scientists around the world, along with partners such as Global Environment Facility, the World Bank, and NOAA, conducted the research.
Eakin explained that warmer and more acidic oceans cause coral bleaching and death. The study asserts that will expose people to flooding, coastal erosion and loss of food. Images provide a clear, and now common, example of bleaching in coral reefs. "Coral reefs are hugely important. Number one, they are one of the most diverse ecosystems in the marine environment. There are more fish on the coral reefs than in the rest of the oceans combined, more species of fish."
In the Caribbean region, the report states the $100 billion a year scuba-diving and tourism industry relies on healthy coral reefs and nearby beaches.
Eakin says, "About two billion people in Southeast Asia alone rely on coral reef fish as a major source of protein."
NOAA has 33 monitoring stations in the Americas that have collected data on climate change over several decades. According to the study, change is coming too fast.
"We are seeing increases in temperature at rates that we haven't seeing any time in the last several hundred thousand years. So, the problem here is that while corals can adapt, we don't see any evidence that they are going to be able to adapt quickly enough to respond to these rapid changes," Eakin said.
Scientists estimate that at least 30 percent of the world's coral reefs are already dead. The study calls for drastic action to save as much as possible of the coral reef.
The study urges world leaders reduce carbon dioxide emissions, stop overfishing and unsustainable development.
NOAA's coral reef coordinator, Mark Eakin, says it is important for people to understand that the life of the oceans depends, also, on similiar actions by individuals and local governments.