Climate change is changing our wind patterns, which is strengthening the waves that travel across the earth's surface.
As climate change has gradually warmed the oceans around the world, it has also been making ocean waves stronger and more deadly, according to a new study published in Nature Monday.
The upper ocean waves are driven by local wind patterns, which are driven by temperature differences between different layers of the air. So as we pump greenhouse gases into the atmosphere and heat the air, we are also strengthening certain wind patterns and weakening others. The net effect is that our oceans are stronger winds and make stronger waves.
"We show that global wave power, which is the transport of energy transferred from the wind to the motion of the sea surface, has increased globally," the authors wrote.
For people who work in industries that depend on shipping, such as fishing and global freight, this means their already dangerous jobs will become even more dangerous over time. Specifically, commercial fishing has a mortality rate 32 times greater than the general U.S. working population, and 18 percent of these deaths can be attributed to waves.
The study found that waves, on average, have strengthened 0.41 percent each year from 1948 to 2008, measured in kilowatts per meter. This may not sound like a lot, but consider this an average. The waves in the Southern Ocean, which surrounds Antarctica, have strengthened by about 2 percent each year.
It's already incredibly dangerous to travel to Antarctica by sea: heavy-duty icebreakers are required in areas with more sea ice, and an ultra-luxury tourism trend of cruising to the frozen continent has been growing steadily almost every year.
It is often easier and safer to travel to Antarctica by plane, and we will probably have to rely on that method even more in the future. But that requires building more expensive and destructive tracks in the frozen landscape. (China plans to build a nearly one-kilometer airstrip for the researchers.)
A graph showing the changes in wave power over time.
2017 was the warmest year on record for global oceans, largely because the oceans absorb 90 percent of the additional heat in the atmosphere generated by humans due to our release of greenhouse gases. The oceans also warm more slowly than other global areas, such as forests, deserts, or even the air. This means that, in general and over time, the oceans have a greater ability to warm up and stay warm for a long time. The ways we are altering our oceans will persist for years.
It is worth noting that we are also affecting the ocean in places that we cannot see. The Atlantic Dump Circulation (AMOC) is a global circulation process that sends cold water to the surface and warm water to the deep sea around the world, which helps regulate salt levels around the world. Since climate change is heating ocean water everywhere, this process has weakened, putting all salinity-specialized ocean creatures at risk.
The consequences of climate change go far beyond making our world a little warmer each year. As we emit greenhouse gases, we initiate environmental feedback processes to which the ocean is particularly vulnerable.
Original article (in English)