Strange 'cold tongue' phenomenon is happening in the Pacific Ocean, scientists have not explained it yet

The eastern Pacific Ocean has a current of water that is getting colder, contrary to scientists' climate models .

The mystery of the Pacific "cold tongue"

For years, climate models have predicted that as greenhouse gas emissions increase, the oceans will warm, including the Pacific.

But in one part of the Pacific, the opposite is happening. Thousands of kilometers from the coast of Ecuador in the east to the west flows a stream of water that has been cooling for the past 30 years . This stream is called the "cold tongue" by scientists .

The question is, will this cooling process ever stop, or will it suddenly switch to a warming state?

Mr. Pedro DiNezio at the University of Colorado Boulder (USA) said this is the most important question that has not been answered by climate science.

The Pacific Ocean is the largest and deepest ocean on Earth. Its surface area is larger than all the land masses combined. That's why scientists have struggled to understand how it will respond to increasing greenhouse gases in the atmosphere.

The Pacific "cold tongue" is a cold ocean current flowing from Ecuador - (Photo: SHUTTERSTOCK).

Richard Seager at Columbia University in New York was among the first to warn in 1997 that the equatorial Pacific was cooling, a trend not seen in climate models.

Sea surface temperature data have since confirmed Mr Seager's suspicions.

The eastern Pacific (near the Americas) has always been 5–6°C colder on average than the western part of the ocean (near Asia). But between 1980 and 2019, this temperature difference has increased by about 0.5°C.

Climate models wrong?

Today, more and more scientists share Mr. Seager's doubts about the temperature of the "cold tongue."

If climate models do not reflect the 'cold tongue,' they can seriously misrepresent the climate.

'We need to find out what it is,' said Isla Simpson at the US National Center for Atmospheric Research. ' This is really important because the 'cold tongue' will have huge implications for the future of Earth's climate. '

Warmer waters in the western Pacific and colder waters in the eastern Pacific lead to more clouds over large swaths of the eastern Pacific.

More clouds mean more sunlight is reflected, says David Battisti at the University of Washington in Seattle. In other words, a cooler eastern Pacific would slow global warming.

If the "cold tongue" continues to cool, it could reduce the expected rate of global warming by up to 30 percent compared to predictions from climate models, according to climatologists .

That also means the baseline climate will be more like La Niña, increasing the risk of drought in the Horn of Africa and the US Southwest — which could mean a permanent megadrought in the US.

On the other hand, if climate models work correctly and the eastern Pacific warms, the rate of global warming will be higher and there will be different regional impacts.

The baseline climate will then become more like El Niño, increasing coral bleaching, making the Amazon hotter and drier; causing more droughts in Australia and Indonesia; and leading to severe heat waves in India.

Meanwhile, regions in the Americas will see more storms. Storms with heavy rains will lead to severe flooding and landslides in countries such as Peru and Ecuador.

Researchers first discovered the "cold tongue" in the 1990s, when they dismissed it as a natural extreme variation of the region.

Any change in this 'tongue of cold' has global implications. It could determine whether California is hit by a chronic drought, or deadly wildfires besiege Australia, or the intensity of India's monsoons and the risk of famine in the Horn of Africa…

It could even alter the extent of global climate change, with increasing greenhouse gas emissions.