Changes in Atlantic Ocean current may be sign of climate tipping point, scientist says

New research indicates warmer oceans may change ocean currents and atmospheric patterns in a big way.

In this episode of Climate Cast, MPR News chief meteorologist Paul Huttner continues his conversation with John Abraham of the University of St. Thomas about shifting currents in the Atlantic Ocean and the importance of measuring ocean temperatures.

The following conversation has been lightly edited for clarity. Click play on the audio player above to listen to this episode, or subscribe to the Climate Cast podcast.

Have we passed a tipping point?

It’s hard to know when a tipping point happens. In fact, typically we will pass a tipping point before we know we’ve passed it. That actually may have been what happened with this ocean. We may have passed a tipping point, and these scientists are just telling us, in retrospect, that we’ve passed it.

Climate change is complicated in a lot of ways, but in one way, it’s very simple. If you change the chemistry of the atmosphere, you’re going to change the physical response.

That’s right. And guess what? We have known that for over 150 years. The first researchers on connecting chemistry to climate were in the 1800s. This is something that’s well known, and we are literally watching history unfold.

Let’s do a status check on climate change here in late 2025. What are the most important trends you’re seeing right now?

I’m particular to the ocean, so the most important one in my mind is measuring ocean temperatures. You’ve heard the analogy “a watched pot never boils,” and that’s really true. Water is able to take in a lot of heat before its temperature rises, and it turns out more than 90 percent of global warming heat ends up in the oceans.

My team is measuring ocean temperatures every year, and we’re watching changes to salinity in the ocean. Because parts of the ocean are becoming saltier, and parts of them are becoming less salty. We’re actually seeing changes to the density in the ocean.

The third point I’ll mention, is the impacts on extreme weather. As the climate change evolves, we are seeing more and more extreme weather. That affects us everywhere, including Minnesota.

What can each of us do in this current political and atmospheric climate to help slow down climate change?

We are at a point where it is cheaper to power our homes, our cars and our businesses with clean green energy like wind and solar than to do it with fossil fuel. Minnesota is a major producer of electricity from wind and solar. We don’t have to import coal from West Virginia. We can export wind energy to other states. So we’re in a situation where we can save the environment and save money.

At the same time, we can create those high-quality, high-skilled jobs here in Minnesota. We have technical solutions that can make this problem less bad, and those solutions can build jobs and save us money.

That’s what makes me optimistic. It’s the economics of green energy. That is unstoppable, regardless of any political issues happening.