Our oceans cover 71% of the Earth's surface yet our knowledge of marine climate change impacts is a mere drop in the ocean compared to terrestrial systems. Our oceans supply valuable ecosystem services and are vital in regulating the Earth's climate. For example, over half the world's oxygen is produced by marine phytoplankton and the oceans provide valuable protein as food, particularly for developing nations. In the IPCC (Intergovernmental Panel on Climate Change) Fourth Assessment Report, 28,586 significant biological changes were reported in terrestrial systems, but only 85 (<0.3%) were from marine and freshwater systems. This Working Group aimed to provide the globally coherent view of marine biological changes in response to climate change. To do so, they assembled a group of scientists specializing in the ecology of species from plankton to seabirds, across regions from the tropics to the poles, over multiple time scales (decadal to paleo), and in global meta-analyses to synthesize the marine biological impacts of climate change.
This Working Group built a database of marine climate impacts studies to analyze the observed changes in distributions and phenology of marine species. Preliminary evidence suggested marine biological systems may be more responsive to warming than terrestrial systems, and indeed, that is what their findings concluded. They compared marine rates of change with those from terrestrial systems and also compared rates of change between regions, systems and taxonomic groups.
A critical issue that was addressed was the role of multiple human stressors, such as fishing pressure, in determining the vulnerability of species and habitats to climate change. For example, heavily exploited species have a smaller gene pool and might exhibit reduced resilience to environmental change. This enabled the team to provide guidance on whether measures that reduce additional human stressors (e.g., fishing pressure) could provide a key adaptation strategy to reduce the threat of climate change in marine systems. The final goal was to attribute change in marine ecosystems to climate change exploring a number of approaches such as joint-attribution and using paleo-data.
This group's research findings have been featured in a range of media including: