Climate change is already affecting many of the world’s ecosystems with far-reaching impacts. In this special issue, contributors focus on the current and projected impacts of climate change across different geographical regions of Oceania (Australia, Pacific Islands and New Zealand). In this synthesis, we examine how climate change is affecting the three main realms: terrestrial, freshwater (broadly including estuarine and inland saline systems), and marine. Within this context, we also examine general strategies for climate adaptation including reducing other threats (e.g., habitat loss and degradation), expanding protected areas, increasing connectivity, restoring habitat and translocations. We show that many of these general strategies will not overcome all the threats caused by climate change and specific solutions are likely to be necessary. Beyond the implementation of these strategies, there are significant future challenges that will hamper effective adaptation that need to be overcome by the scientific community. Our current understanding of the impacts of climate change on biodiversity remains poor; this is particularly true for poor nations in the region. There is also considerable uncertainty in forecasts of climate change, particularly at the local scale, and this uncertainty impacts pro-active planning. This makes effective implementation particularly challenging. Considerable focus is needed on ecosystem-based adaptation where local communities are integrally involved, allied with more active and accountable management of conservation, through adaptive management processes. The world is experiencing far-reaching and long-term changes to ecosystems with major impacts on human communities, particularly in relation to ecosystem services. Our ability to develop effective adaptation strategies from the broad-scale policy (e.g., emissions control) to local-scale management (e.g., building resilience in ecosystems) will be significantly tested but the world is in an important period and scientists and practitioners need to keep trying different approaches and reporting their successes and failures to the wider community.