Q: What is the Gulf Stream?

The Gulf Stream is a large-scale warm ocean current that crosses the Atlantic Ocean. It originates in Florida before following the coastline of North America and then crossing the ocean towards Europe. The Gulf Stream, which has more than 100 times the flow of the Amazon river, is part of a system of five circular gyres in the North Atlantic. 

The existence of the Gulf Stream means that the UK and other northern European nations are much warmer than other countries at the same latitudeThe angular distance of a place north or south of the equator. . For example, England is as far from the equator as some parts of Canada - but Canada is much colder. 

Q: How does it work?

As warm water flows from the equator towards the poles it cools down. Some water also begins to evaporate, increasing the salt content of the current. The low temperature and high salinity makes the water denser, causing it to sink. 

Eventually, the water is pulled back to the surface and warms up again. This process, known as upwelling, completes the circulation of the gulf stream. Ocean currents like the Gulf Stream ensure heat is distributed all around the planet. 

Q: When was it discovered?

In 1513, the Spanish explorer Ponce de LeonJuan Ponce de Leon led the first official European expedition to Florida and was the first governor of Puerto Rico.  was the first to notice the strong ocean current. The pilot of his ship later realised that sailing along the Gulf Stream could speed up their journey from Mexico to Spain.

The first person to chart the course of the current on a map was the American Founding Father Benjamin FranklinA writer, politician, diplomat and scientist who pioneered the use of electricity and was one of the Founding Fathers of the USA. in the late 18th Century.  

Q: What is happening to the gulf stream?

The Gulf Stream is slowing down. Last year, a team of scientists used data from environmental records such as tree rings, temperature and coral records to look back into the past. "We found consistent evidence that the system over the last decades has been weaker than any time before in the last 1,600 years," said climatologist Levke Caesar.

Scientists believe global warming has increased the level of freshwater at the ocean's surface, due to melting ice sheets and higher annual rainfall. This reduces the density and salinity of the water at the northern end of the Gulf Stream, slowing the sinking of the water and weakening its overall flow.

Q: Why does it matter?

Changes to the Gulf Stream could affect the climate across Europe, North America and the world. The slowdown could lead to more "extreme and intense" winters in Europe, flooding on the east coast of the United States and sudden regional sea level rises.

It could also disrupt monsoon seasons in India, South America and West Africa, affecting food production for billions.

Q: What happens next?

Models suggest the Gulf Stream could weaken by another 34% to 45% by 2100, but nobody knows for sure what will happen. "These signs of decreasing stability are concerning," says paleoceanographerThe scientific study of the Earth's oceanographic history involving analysis of sediment and the tectonic plates. David Thornalley. "But we still don't know if a collapse will occur, or how close we might be to it."

Ultimately, experts warn that humans must take action now to prevent more global warming.