Oceans are warming faster than ever. Here’s what could come next.
The worlds oceans have been warming for generations, a trend that is accelerating and threatens to fuel more supercharged storms, devastate marine ecosystems and upend the lives and livelihoods of millions of people, according to a new scientific analysis. Published this week in the journal Nature Reviews, it finds that the upper reaches of the oceans roughly the top 2,000 meters, or just over a mile have been heating up around the planet since at least the 1950s, with the most stark changes observed in the Atlantic and Southern oceans. The authors of the review, who include scientists from China, France, the United States and Australia, write that data shows the heating has both accelerated over time and increasingly has reached deeper and deeper depths. That warming which the scientists said probably is irreversible through 2100 is poised to continue, and to create new hot spots around the globe, especially if humans fail to make significant and rapid cuts to greenhouse gas emissions. The findings underscore both the key role the oceans have played in helping to offset human emissions oceans absorb more than 90 percent of the excess heat trapped within the worlds atmosphere and also the profound implications if the warming continues unabated. If it does, the areas near the surface of the oceans could warm two to six times as much as they already have, scientists wrote. Global warming really does mean ocean warming, Kevin E. Trenberth , a co-author of the review and a scholar at the National Center for Atmospheric Research, said in an interview from New Zealand. The best single indicator that the planet is warming is the ocean warming record. U.N. climate report: Monumental change already here for worlds oceans and frozen regions That record, composed of thousands of temperature measurements across the globe over decades, he said, shows a relentless trajectory. The warming has been accelerating, and the most rapid warming rates have been in the last 10 years or so, he said. The consequences of hotter oceans already are on display in numerous ways. Scientists attribute about 40 percent of global sea level rise to the effects of thermal expansion in ocean water. Warmer oceans also speed the melting of ice sheets, adding to rising seas. They disrupt traditional weather patterns and deepen drought in some areas. And they fuel more intense hurricanes, as well as create the conditions for more torrential rainfall and deadly flooding. The authors cite one example from August 2017, when the Gulf of Mexico reached the warmest summertime temperature on record to that point. That same month, Hurricane Harvey tore through the gulf, exploding from a tropical depression to a major hurricane and dumping catastrophic amounts of rain on Houston and other areas. All of these things are part of the fact that theres extra energy available in the oceans, Trenberth said. In addition, the analysis found that future warming could cause precipitous drops in certain fisheries, causing the loss of livelihoods and food sources. The trend also makes it inevitable that marine heat waves will become more extensive and longer-lasting a reality that can trigger toxic algal blooms and fuel massive mortality events among coral reefs, kelp forests and other ocean life. Sea level to rise one foot along U.S. coastlines by 2050, government report finds While the authors make clear that oceans around the world are projected to continue warming over the coming decades, even if humanity begins to cut greenhouse gas emissions , that warming will not happen equally across the globe. Largely due to circulation patterns, some regions are projected to warm faster than others and are likely to grapple with more intense impacts. The paper also underscores that while many uncertainties remain, how that plays out is critical to the consequences humans will probably experience, said Joellen Russell, a professor and oceanographer at the University of Arizona. A small fraction more [mixing] would slow our warming, and a small fraction less mixing would accelerate our warming, said Russell, who was not involved in this weeks analysis. That is incredibly important for people to understand. The latest findings are largely in line with the growing body of research has documented that oceans have long stored astounding amounts of energy from the atmosphere and mitigated the impacts of greenhouse gas emissions, but that over time profound impacts are unavoidable on land and at sea. In its most recent assessment on the state of climate science earlier this year, the Intergovernmental Panel on Climate Change said it is virtually certain that the upper swath of the oceans have warmed over the past half-century, and that human-caused carbon emissions are the main driver. Global mean sea level has risen faster since 1900 than over any preceding century in at least the last 3,000 years, the IPCC wrote. The global ocean has warmed faster over the past century than since the end of the last deglacial transition (around 11,000 years ago). Still, researchers say the amount of future warming depends on what humans do or dont do to rein-in the greenhouse gases that ultimately are heating oceans. And better measuring, understanding and mitigating the problem should be a global priority. If the world can steer toward a future with the kind of rapidly shrinking emissions envisioned by the Paris climate agreement , the author of this weeks review write, that would probably lead to a detectable and lasting reduction in [the] ocean warming rate, with noticeable reductions in climate-change impacts. Russell said the latest findings emphasize that it absolutely matters that humans cut emissions as quickly as possible, to limit warming in the oceans and the ripple effects that ultimately has for humans. Our oceans are doing us a profound service, she said. As a scientist and a mom, I pray about the fact we need to bend that curve in my lifetime. ... It is important that we do this. Chris Mooney contributed to this report. Sign up for the latest news about climate change, energy and the environment, delivered every Thursday Understanding our climate: Global warming is a real phenomenon , and weather disasters are undeniably linked to it . As temperatures rise, heat waves are more often sweeping the globe and parts of the world are becoming too hot to survive . What can be done? The Post is tracking a variety of climate solutions , as well as the Biden administrations actions on environmental issues . It can feel overwhelming facing the impacts of climate change, but there are ways to cope with climate anxiety . Inventive solutions: Some people have built off-the-grid homes from trash to stand up to a changing climate. As seas rise, others are exploring how to harness marine energy . What about your role in climate change? Our climate coach Michael J. Coren is answering questions about environmental choices in our everyday lives. Submit yours here. You can also sign up for our Climate Coach newsletter .