FY 2021 Introduction to El Niño Southern Oscillation in a Changing Climate McPhaden, M.J., A. Santoso, and W. Cai Chapter 1 in El Niño Southern Oscillation in a Changing Climate, M.J. McPhaden, A. Santoso, and W. Cai (eds.), Geophysical Monograph 253, American Geophysical Union, Wiley, 1–19, doi: 10.1002/9781119548164.ch1, View online (2020) Summary. El Niño and the Southern Oscillation (ENSO) is a naturally occurring fluctuation of the climate system that is generated in the tropical Pacific through interactions between the ocean and the atmosphere. It is the strongest year‐to‐year climate variation on the planet, with environmental and societal consequences felt worldwide. ENSO warm events (El Niño) and cold events (La Niña) are occurring in the context of a global climate system that is rapidly changing through human activities that have raised heat‐trapping greenhouse gas concentrations in the atmosphere to historically unprecedented levels. As a result, the planet has warmed, and it will continue to warm at a rate dependent on future greenhouse gas emissions. This raises questions about whether climate change has affected the ENSO cycle already, whether it will in the future, and if so, how. Here, we briefly describe ENSO and its impacts; highlight the history of ideas and events that have shaped our understanding of ENSO; discuss current challenges in ENSO research; and address why ENSO in a changing climate is such an urgent problem in Earth system science today. Feature Publications | Outstanding Scientific Publications Contact Sandra Bigley | Help
