Darkest ocean depths prone to global warming

GLOBAL warming may be heating up the almost freezing waters up to 15,600ft below the surface of the ocean, a study has found.

Temperatures recorded at four stations in the Atlantic off the coast of Uruguay were found to be warmer than they were 10 years ago.

The link with emissions caused by human activity is not confirmed, but t he authors of the report said the 0.02C temperature rise was “consistent with the sign of the well-documented planetary-scale global warming trend”.

Lead author Chris Meinen, said more data was needed to prove a link with warming in the wider atmosphere.

On land, scientists examine evidence from fossils, tree rings and ice cores to interpret temperature trends over thousands of years – a body of data that is not yet available in the ocean.

“In the deep ocean, we don’t have that thousand years of information to compare to,” Mr Meinen said.

“So while we’re seeing a trend down there, we can say is consistent with the broader- scale picture of global warming that we’re seeing, we have to be cautious and not say more than what the data supports, in terms of the reason why we’re seeing warming in the deep ocean.

“It’s logical to say that it’s consistent with global warming, but we can’t prove that at this stage.”

The data, published in the journal Geophysical Research Letters, showed a surprising amount of shorter-term variation, with temperatures shifting over hours and days much more than expected, Mr Meinen added.

Since the middle of the last century, oceans have absorbed more than 90 per cent of the extra heat kept in the earth’s atmosphere by greenhouse gases.

This slows the warming trend on land, but also has consequences for marine life. It also raises global sea levels, contributing to melting ice caps and damaging ocean ecosystems.