Humans are destroying Earth's oceans, that much is clear. Before 2008, there were only four very large marine protected areas, or MPAs, in the planet. Now, that number has ballooned to over 30.

In total, there are 8,236 MPAs in the world, and they're very restrictive places. In such areas, humans aren't allowed to mine, dig for oil, or even fish. By avoiding the plight of destructive human intervention, scientists hope these areas will eventually help recover marine life.

There's one big problem, however. While MPAs might help in the short-term, they can't singlehandedly prevent the oceans from undergoing drastic change over global warming.

Global Warming Puts Marine Protected Areas At Risk

According to a new study published in the journal Nature Climate Change, oceans will eventually undergo staggering changes to the point where marine life simply won't be able to survive. Eliminating the human activities mentioned above won't help, either.

The study simulated two scenarios: one where temperatures rise to 8.5 degrees Celsius by the end of the century, and another where humans are somehow able to control rising temperatures down to just 4.5 degrees Celsius. Both are no good as marine life suffers either way.

The study claims that oceans will undergo increased storm intensity, rising sea levels, acidification, water warming, oxygen loss, and many others.

What Could Happen

The study concludes that rapid and extreme warming would yield devastating effects on the species and ecosystems located inside MPAs. Ultimately, these radical changes could result in the total extinction of some animals, loss of biodiversity, and changes in ocean food webs.

Most animals living in many of these MPAs exist in small populations with low genetic diversity, and it's highly likely they won't be able to adapt to ocean warming.

If global warming continues to worsen, many animal species inside the MPAs will disappear by the turn of the century, according to Lead scientist John Bruno, a professor from the University of North Carolina.

"To avoid the worst outcomes, we need to immediately adopt an emission reduction scenario in which emissions peak within the next two decades and then decrease very significantly," said Bruno.

At greatest risk are MPAs in the Arctic and Antarctic regions, according to the researchers. These places will likely warm very quickly, which spells disaster for the future of polar bears and penguins. Other high-risk areas include the Wolf and Darwin islands in northern Galapagos.

Rich Aronson, a researcher on the study, believes humans are already out of time in terms of establishing marine reserves while scientists determine how best to confront climate change.

"We have to control greenhouse gas emissions," said Aronson.