The top journal Nature published an article entitled“Increased variability of eastern Pacific El Niño under greenhouse warming”recently. The first author of this article is Dr. CAI Wenju, chief scientist of QNLM and director of the Centre for Southern Hemisphere Oceans Research (CSHOR). Academician WU Lixin, director of QNLM Executive Committee, is the co-corresponding author. Nature issued a press release to the media around the world, and invited experts in the same field to write news and views to comment on the research results.
The article reveals that the increased variability of the eastern Pacific El Niño under greenhouse warming has a significant impact on global extreme weather events, ecosystem and agriculture. Dr. CAi Wenju remarked that, the El Niño–Southern Oscillation (ENSO) is the dominant and most consequential climate variation on Earth, and is characterized by warming of equatorial Pacific sea surface temperatures (SSTs) during the El Niño phase and cooling during the La Niña phase. ENSO events tend to have a centre—corresponding to the location of the maximum SST anomaly—in either the central equatorial Pacific (5° S–5° N, 160° E–150° W) or the eastern equatorial Pacific (5° S–5° N, 150°–90° W); these two distinct types of ENSO event are referred to as the CP-ENSO and EP-ENSO regimes respectively. The researchers find a robust increase in future EP-ENSO SST variability among CMIP5 climate models that simulate the two distinct ENSO regimes. The EP-ENSO SST anomaly pattern and its centre differ greatly from one model to another, and therefore cannot be well represented by a single SST ‘index’ at the observed centre. However, although the locations of the anomaly centres differ in each model, researchers find a robust increase in SST variability at each anomaly centre across the majority of models considered. This increase in variability is largely due to greenhouse-warming-induced intensification of upper-ocean stratification in the equatorial Pacific, which enhances ocean–atmosphere coupling. An increase in SST variance implies an increase in the number of ‘strong’ EP-El Niño events (corresponding to large SST anomalies) and associated extreme weather events.
EP-El Niño events are the strongest and most destructive El Niño events. During such events, SST warming in the Niño region leads to flooding in southwest USA, Ecuador and northeast Peru, and to droughts in regions that border the western Pacific. In extreme cases, the disruption includes substantial loss of marine life in the eastern Pacific, mass bleaching of corals across the Pacific and beyond, and movement of the intertropical convergence zone and of the South Pacific convergence zone towards the equator, inducing catastrophic floods and droughts across the Pacific region.
Climate change is a huge challenge for global sustainable development, and El Niño's response to greenhouse gas emissions is one of the most important issues in global climate change research. As China's first national laboratory approved for pilot operation, QNLM actively promotes international cooperation and collaborative innovation in response to global climate change. QNLM has endeavored to achieve ultra-high resolution predictions for marine environment and climate for the coming decades.
According to Academician WU Lixin, QNLM will actively contribute wisdom and strength to solving global problems facing humanity including El Niño. QNLM will make unremitting efforts to promote climate change research and construction of the community with a shared future for mankind.
The link of this article on Nature is as follows: