Studying Coral Fossils to Understand Recent Climate Changes and Extreme El Niño Events in the Tropical Pacific

The El Niño/Southern Oscillation (ENSO) is a climate pattern in the tropical Pacific Ocean that affects weather worldwide every 2-8 years, causing changes in temperature and rainfall. These changes can lead to severe weather events like storms, droughts, and floods, impacting millions of people, especially those in vulnerable regions.

Recently, extreme El Niño events (such as those in 1982/83, 1997/98, and 2015/16) have raised concerns that human activities and greenhouse gases might be making these events more intense. However, we still don’t fully understand what causes these events or how they will change in the future due to climate change.
One major challenge is the lack of detailed climate data from before 1970. To overcome this, scientists can study ancient coral records, which act like natural climate archives, showing past ocean conditions. These corals, especially those found in the tropical Pacific, help us understand how climate patterns like ENSO have changed over thousands of years.

A recent global study highlighted in an important climate report included 46 coral records, mostly from the western Pacific and Atlantic Oceans. However, only six of these records came from the central/eastern Pacific, a crucial area for understanding global climate changes. Most existing coral records cover only the last few centuries, with less than 10 records from before 1700.

To fill this gap, this project plans to expand the number of coral-based climate records from the tropical Pacific over the last 3,000 years. Scientists will collect and analyze smaller coral pieces from various locations, using advanced techniques to determine precise temperature data. This work will create the most detailed record yet of ocean temperatures in this region, helping us understand how ENSO and climate patterns have changed over time and what we might expect in the future.