Future climate change will increase risk to mangrove health in Northern Australia

Abstract

Mangroves of the wet-dry tropical Gulf of Carpentaria, Australia, survive in a harsh environment. One of the worst recorded mangrove dieback events occurred during the El Niño of 2015 following an extreme, two-year sea level drop, illustrating that enhanced climate variability can exacerbate major stressors for these ecosystems. As well as sea level variability, maximum daily temperatures in the Gulf of Carpentaria are also linked to climate variability and change, and may play an important role in overall mangrove health. Here we address how these two factors: sea level variability and maximum daily temperatures, are projected to change under several future emissions scenarios. Climate projections from the sixth generation of Coupled Model Intercomparison Project indicate an increased occurrence of anomalously low and high sea level events in the coming century. This, alongside enhanced temperature stress, is likely to significantly increase risk to mangrove health in this region. The rate of increase of low and high sea level events, and high temperature events, is scenario-dependent, and is largest for a high-emissions scenario.