The upper part of our oceans threatens to change forever

Current ocean surface conditions could completely disappear within 80 years. But it is not a foregone conclusion yet.

Global oceans already exist Significantly affected by climate change. Our carbon dioxide emissions, for example, are causing water temperatures to rise and acidify. in a New study Researchers have figured out exactly how these things affect the ocean surface. And according to them, the vast majority may never be the same again.

ocean surface
The ocean surface is a strip of sea water that reaches from where air meets water to a depth of about 100 metres. It is a part of the sea that directly interacts with elevated levels of carbon dioxide in the atmosphere. That seawater absorbs carbon dioxide in the air until the two balance out. So the more carbon dioxide there is in the atmosphere, the more it is at the ocean surface.

study
Researchers in a new study were curious about how the surface of the global ocean has changed due to climate change. To find out, they used atmospheric data for carbon dioxide. They then modeled what global ocean climate might look like by 2100 under two different scenarios. The first scenario is a more favorable scenario, with emissions peaking in 2050 and then declining. The second scenario is the dreaded ‘business as usual’ scenario, in which no restrictive measures are imposed globally to structurally reduce CO2 emissions and we continue at the current pace, with emissions peaking in 2100. In addition, the researchers also looked at The time is right and they study how the upper part of our oceans changed between the nineteenth century and the first decade of the twenty-first century.

forever changed
The results show that the ocean climate did not change significantly during the nineteenth and twentieth centuries. But by 2100, ocean surface conditions may be forever different. If we do nothing about our carbon dioxide emissions, the ocean surface will experience much higher temperatures and an increasingly lower pH value by the end of this century. This is particularly harmful to shellfish. In more acidic waters, it is difficult for most shellfish — such as oysters and snails — and corals to extract calcium from the water. This is because lime dissolves faster in acidic water. “The climates that disappear are the ones where the pH rises,” researcher Katie Lauterhus explains. “And these are precisely the conditions in which organisms can make shells more easily.”

During eighty years
In their study, the researchers state that, in the worst case, 95% of the currently prevailing ocean surface conditions could completely disappear within 80 years. This means that if we do nothing about carbon dioxide emissions, the upper ocean may never be the same. This is especially sad for the animals who live there and will encounter conditions they have never seen before. Additionally, oysters can have great difficulty forming their calcareous shells in more acidic waters. “In the worst case, the shells that make living things can dissolve in seawater instantly,” Loterhaus says.

It’s never too late
While this is a very dark picture of the future, the researchers argue that it’s not too late to do something about it. This is not a foregone conclusion yet, Lotterhus stresses. In the most favorable scenario, about 35 percent of current ocean surface conditions are expected to disappear. “It’s quite surprising that there is such a difference in expectations,” says Loterhus. “Mitigating is very important and can really make a big difference.”

changeable
Although ocean surface conditions are indeed changeable, things are generally relatively fine. “Although we have already seen warming and acidification, it is out of proportion to what species have experienced over the past two hundred years,” Lotterhus concludes. “It was only in the next 80 years that we started to see the emergence of new climates. And that gives a glimmer of hope.”

However, at the moment, much remains unknown about how exactly ocean animals respond to changes in their environment. “Some may not be adversely affected,” Loterhus said. For example, some species, such as phytoplankton, may benefit from increased levels of carbon dioxide because they use it for photosynthesis. Or perhaps some species are able to evolve fast enough to survive in new conditions. “When we talk about climate change, there are winners and losers,” the researcher continues. It can be harmful to some species and we can expect to change. But whether all the changes will also be negative … this is not necessarily the case. “