Robots swimming all around the world are sending ocean temperature readings back to Seattle, and one of the scientists who's paying close attention says the oceans are trapping so much heat, it could have many serious consequences.
"The Argo program is an international collaboration of scientists from around the world who have deployed an army of these around the global oceans. Every 10 days, these floats go on a cycle. They sink down to about a mile and a quarter deep, and they stay there for about 10 days. Then, as they rise up, they measure temperature and salinity, all the way up to the surface of the ocean. And then they phone home, and we make those data publicly available on the web," said NOAA Oceanographer Greg Johnson. "We are measuring to within .002 degrees Fahrenheit the temperature of the ocean."
When it comes to absorbing heat, the oceans put the atmosphere to shame. For every degree Celsius of warming, a pound of water can absorb four times as much heat as a pound of air. The oceans have a mass that is 280 times the mass of the atmosphere. Therefore, the heat absorbed by a one-degree warming of the ocean is roughly equal to that of 1,000 degrees of warming in the atmosphere.
It takes decades for the oceans to warm in response to greenhouse gases, whereas the atmosphere warms much more quickly. Johnson compared it to the difference between a tea kettle and a hairdryer.
"If you had each of the 7.5 billion people on the planet running 30 electric tea kettles going into the ocean, dipping them in and taking them out, running continuously over that 10 years, that's how much energy we are putting in," Johnson said.
There are 4,000 robotic floats returning 160,000 profiles a year. The robots are showing that the oceans absorb about 93 percent of Earth's warming.
The result could range from severe storms, sea level rise, and many other serious conditions with which human infrastructure will have to contend.
"The seas are rising and will continue to rise even if we get our act together," Johnson said. "Climate change is something, because of the huge thermal inertia of the oceans. I like to think of it as a freight train. We've pushed it, and it's moving now, and it's actually going to take some effort to slow it down."