Methodology
They calculate and map the cumulative impact of 19 different types of anthropogenic stress on 20 global marine ecosystem types using global-scale data as of 2013. For 12 of these anthropogenic stressors, they used equivalent methods and data sources in the current and previous (5 years before) time periods, allowing assessment of the 5-year change in their individual and cumulative impacts. To help identify regions with different management and conservation needs, they identify areas experiencing the greatest and least cumulative impact and highest or lowest amount of change. Cumulative impact (IC) is the per-pixel average of the habitat vulnerability-weighted stressor intensities where weights (μi,j) are determined by the vulnerability of each i... m habitat (E) to each j... n stressor (D).
Data description
This layer shows calculated and mapped recent changes over 5 years in cumulative impacts to marine ecosystems globally from fishing, climate change, and ocean- and land-based stressors. Nearly 66% of the ocean and 77% of national jurisdictions show increased human impact, driven mostly by climate change pressures. Five percent of the ocean is heavily impacted with increasing pressures, requiring management attention. Ten percent has very low impact with decreasing pressures. This data provides large-scale guidance about where to prioritize management efforts and affirm the importance of addressing climate change to maintain and improve the condition of marine ecosystems.
Indicator
Potentially disappeared fractions of species (PDF) - Climate change
Method / tool
IMPACT World+