Coastal ecosystems in the Coral Triangle are already being impacted by warming, acidifying, and rising seas. Coral reefs have experienced severe mass bleaching events across the region, which, if they increase in intensity and frequency, threaten to seriously degrade these important ecosystems. Mangroves face similar problems with rising sea levels threatening their future. With the build up of coastal infrastructure, there is no place for mangroves to retreat. The downstream effects on human beings of losing these critical coastal ecosystems are enormous. Basically, the future is looking very gloomy unless we act immediately and decisively.

This report brings together a vast amount of information from the climate, biological, economic, policy and social sciences to build credible pictures of two potential worlds. These two worlds are instructive in terms of the impact of the decisions that we take today.

In one world, based on the Intergovernmental Panel on Climate Change (IPCC) A1B scenario, our attempts to stabilize the Earth’s climate fail, as does our resolve to deal with the multitude of local threats to the coastal ecosystems in the Coral Triangle. In this world, temperatures soar and the current rich coral reef and mangrove ecosystems disappear, with huge impacts on food security, human survival and regional security. This is a world that we must avoid at all costs.

In the other world, based on a modifi ed version of the B1 scenario of the IPCC, the international community takes decisive and effective action which rapidly reduces greenhouse gas emissions, and resolves to assist countries like the Coral Triangle nations develop effective solutions to the growing problems they face. These actions, while not without challenges, limit the impacts of the changing climate and maximise the resilience of biological, ecological and socioeconomic systems to those climate change impacts that are currently unavoidable. This is a world in which the poorest people are not abandoned to the impacts caused by the developed world.

This report delivers a sombre warning that action must be taken immediately. There are a number of actions (discussed in detail in chapter 10), which, if implemented by regional and world leaders, will avoid this crisis. Let us hope that these actions become central to the future of the Coral Triangle.