The oceans are warmer and more acidic than ever before in recorded history, and likely ever since modern humans evolved. That should worry everyone alive today.

Why? As go the oceans, so goes the health of the globe. Oceans produce more than half the oxygen we breathe, and are critical to regulating the climate. They have absorbed at least 90% of the heat from global warming since 1970, and continue to absorb 2 billion tons of carbon dioxide every year, equal to the weight of all the oil carried by supertankers annually.

This carbon dioxide makes seawater more acidic and kills off many animals that have shells, including many of the smallest animals that feed life in the ocean.

It’s clear that burning fossil fuels is the primary cause of these changes. If we continue on our current path of carbon emissions, we can expect ocean warming to accelerate, with temperatures rising twice as much in the next 40 years as they did in the past 140, further disrupting ocean life and the people who rely on it. Sea levels could rise by up to 6 feet by the end of the century — which would flood parts of many East Coast cities, including New York City.

We can already see that climate change is reshuffling ocean life like a deck of cards. For some, this is a winning hand. Fishermen have caught species they’ve never caught before, including blueline tilefish off New Jersey and Humboldt squid in Washington state.

For many others in the $6 billion U.S. seafood and fishing industry, however, this rapid warming and acidification has brought uncertainty and instability. The $110 million West Coast shellfish industry nearly collapsed over the last decade as acidified ocean water effectively dissolved billions of young oysters before they could grow.

On the East Coast, unusually warm water temperatures appear to have killed surf clams in large numbers off the shores of Delaware, Maryland, and Virginia. This is one of the largest fisheries in the region, and a major processing plant in Virginia has already closed, only to reopen in New England where the clams are still doing well.

A similar story describes lobsters in Long Island Sound. The fishery crashed around 2000 after a string of extreme warm summers, and it hasn’t recovered. Cod, the superlative white fish on dinner plates around the world and the species that first attracted Europeans to North America, is expected to become scarce in U.S. waters as temperatures continue warming.

Away from the U.S., a rapid increase in deadly marine algae off the coast of Chile, driven by warmer oceans, killed up to 20% of the country’s farmed salmon, including millions at four fish farms owned by New York-listed salmon farmer Marine Harvest ASA. US:MHG NO:MHG Chile is the world’s second-largest producer of salmon, and the algal bloom has driven up prices for consumers.

Read:How toxic algae are threatening humans and wildlife across the world

Ocean warming has also destabilized international politics. While no shots were fired, the Mackerel Wars from 2010 resulted from a sharp disagreement between Iceland, the Faeroe Islands, Norway, and the European Union when schools of the valuable fish moved much further north than usual. With everyone catching the fish–and refusing to cooperate and set sustainable catch levels–the stock faced a double (or rather quadruple) jeopardy and was threatened with a collapse. The issue was only resolved in 2014 after trade sanctions and threats eventually led to an agreement to divide the catch equitably.

Even tourism could be affected. An underwater heat wave is devastating huge swaths of Australia’s Great Barrier Reef, a Unesco world-heritage site. The warm temperatures stress the corals, which bleach, revealing the white skeleton underneath. If the heat stress is sustained, the coral begins to starve and will eventually die.

The key point is that these changes are happening now, not in some distant future, and they affect our economy and our dinner plates, as well as our planet.

Avoiding further damage to marine life and further economic impacts will take a two-pronged approach: rapid reductions in greenhouse gas emissions to avoid further global warming, and a new approach to ocean management that can adapt to the unavoidable changes without opening the doors to overfishing. Achieving this will require new science to more effectively set sustainable fishing levels for a warmer, more acidic ocean, as well as greater incentives to use the science we already have.

We can still recover from many of the changes to the ocean so far, but the window for doing so is closing fast.

Malin Pinsky is an assistant professor of ecology, evolution and natural resources at Rutgers University in New Brunswick, N.J., a Sloan Fellow in Ocean Sciences and an affiliate of the Rutgers Climate Institute.