Wednesday , March 22 2023

Climate change is exacerbating waves


As climate change has gradually warmed the oceans around the world, it also makes ocean waves more powerful and deadly, according to a new study published Nature Monday

The upper ocean waves are driven by local wind patterns caused by temperature differences between different air layers. Because we are pumping greenhouse gases into the atmosphere and heating the air, we are also strengthening some wind models and weakening others. The net effect on our oceans is stronger winds that create stronger waves.

"We show that global wave power, which is the transfer of energy from wind to sea surface movements, has increased worldwide," writes the authors.

For people working in maritime industries – such as fishing and global freight – this means that their already dangerous jobs will become even more dangerous over time. For commercial fishing, the mortality rate is 32 times higher than for US workers, and 18% of these deaths may be associated with waves.

The study found that waves averaged 0.41 percent each year from 1948 to 2008, measured in kilowatts per meter. It may not sound like much, but consider it to be average. The waves of the South Ocean, surrounded by Antarctica, each year have gained about 2 percent stronger.

It's already incredibly dangerous to travel to the Antarctic by sea: heavy-duty icebreakers are needed in places with more sea ice, and the trend of ultra-luxury tourism on cruise ships to the frozen continent has steadily increased almost every year.

It is often easier and safer to travel to Antarctica by plane, and we will probably have to rely more on this method. But it requires a more expensive, destructive runway structure on the frozen landscape. (China is planning to build a nearly a mile-long plane for researchers.)

Schedule showing changes in wave power over time.
Picture: Changes in wave power across oceans over time, nature.

The year 2017 was the warmest year for the world's oceans, mostly because the oceans occupy 90 percent of the extra heat generated by the man-made greenhouse gas emissions. The oceans are also heated more slowly than other global arenas such as forests, deserts or even the air. This means that, in general and over time, the oceans have more power, which is hot and lasting for a long time. The way we change our oceans will remain for several years.

It is worth noting that we also affect the ocean in places we cannot see. Atlantic Meridional Rollover Circulation (AMOC) is a global circulation process that sends cold water to the surface and warm water at sea depths around the world, helping to regulate salt levels worldwide. As ocean water is heated everywhere by climate change, this process has weakened, threatening all the creatures of salinity in the specialized ocean.

The effects of climate change are much wider than what makes our world a little hot every year. As we emit greenhouse gas emissions, we are launching environmental feedback processes for which the ocean is particularly vulnerable.

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