A study published this week in the journal Nature Communications finds that climate change will affect up to 86 percent of the world’s oceans within the next few decades—and that it’s not too late to do something about it.

The Coupled Model Intercomparison Project (CMIP) is a large-scale collaboration by atmospheric and climate scientists around the world. The fifth phase of the project, which ended in 2014, yielded 20 different models, or simulations, of our planet’s climate in the past, present, and future.

For the latest study, researchers combined data from 12 of the 20 CMIP models, focusing on how climate change could affect the oceans.

The results were grim. If humans proceed with business as usual and continue to degrade the environment, the researchers say, we can expect to see significant warming and acidification in more than four-fifths of the ocean.

On a global scale, that will mean melting ice caps and rising sea levels. It’ll also affect millions of marine species, including those central to human diet and industry. Changing waters will force species from plankton to polar bears to adapt, migrate, or die.

Migration will not be an option for coldwater species, lead author Stephanie Henson of the British National Oceanography Centre told Reuters. “Arctic fish don’t have anywhere to go.”

“How individual species will fare, or how the ecosystem as the sum of its parts will fare, is poorly understood,” the authors write. “What is clear however is that there are likely to be winners and losers in the future ocean.”

But it wasn’t all bad news. These predictions are based on a future in which humans have failed to protect the planet. It’s not too late, the researchers say, for us to do better.

“The exposure of marine ecosystems to climate change-induced stress can be drastically reduced via climate mitigation measures,” they write. The more steps we take to mitigate climate change, the more time we’ll be able to give marine species to adapt and survive.