Earth May Have Breached Seven of Nine Planetary Boundaries, Health Check Shows

Industrial civilisation is close to breaching a seventh planetary boundary, and may already have crossed it, according to scientists who have compiled the latest report on the state of the world’s life-support systems. Ocean acidification is approaching a critical threshold, particularly in higher-latitude regions, says the latest report on planetary boundaries. The growing acidification poses an increasing threat to marine ecosystems.

Thresholds beyond which they can no longer properly function have already been breached in six. Climate change, the introduction of novel entities, change in biosphere integrity and modification of biogeochemical flows are judged to be in high-risk zones, while planetary boundaries are also transgressed in land system change and freshwater change but to a lesser extent. All have worsened, according to the data. Stratospheric ozone depletion has remained stable, however, and there has been a slight improvement in atmospheric aerosol loading, the research says. At a briefing outlining the findings, Levke Caesar, a climate physicist at PIK and co-author of the report, said there were two reasons the levels of ocean acidification were concerning.