This briefing looks at what the 1.5°C limit means in terms of adaptation and loss and damage for the most vulnerable countries and regions. It finds that slowing down warming is critical to buy us time to adapt and also to avoid irreversible loss and damage. With global warming continuing at an unprecedented rate, and 2023 confirmed as the hottest year on record, it is increasingly important to limit temperature rise and reduce the multidimensional and increasingly irreversible impacts of climate change. This is particularly important for the most vulnerable countries and regions such as Small Island Developing States (SIDS) and Least Developed Countries (LDCs).