Countries earn a lot of media buzz for announcing bold plans to section off thousands of square miles of ocean for protection. That’s because scientists say these Marine Protected Areas (MPAs) are effective tools to protect the marine plants and animals facing threats from ocean acidification, heatwaves, overfishing, and pollution.

MPAs can provide benefits like protecting endangered species or helping replenish fish stocks that spill into neighboring fisheries. The most highly regulated parks have the most benefits. And according to a report released on Wednesday by the UN's Intergovernmental Panel on Climate Change (IPCC), unabated emissions will have severe impacts on biodiversity.

But for MPAs to actually reach the level of protection needed to mitigate