LONDON - US-based climate start-up Running Tide has delivered the first ever carbon removal credits from an open ocean project, it said, with the credits pre-sold to e-commerce group Shopify.

Scientists believe extracting carbon dioxide (CO2) by using nature or technology will be essential to help to meet global goals set under the Paris climate agreement to curb climate change.

Running Tide has completed the first ever carbon removal in the open ocean, funded in part by Shopify, Stacy Kauk, Shopify's head of sustainability, said.

Under Running Tide's carbon removal process, waste wood - such as wood chips - which would otherwise have been burnt, was coated in limestone and placed in the ocean 190 miles south of Iceland. The limestone coating helps to combat ocean acidification, the company said.

The limestone-coated wood spread across the ocean’s surface and sank into water nearly a mile deep, keeping the carbon out of the atmosphere.

A total of 1,000 metric tons of waste wood was sunk throughout May, June and July resulting in a removal of 275 net metric tons of carbon dioxide, Running Tide founder Marty Odlin said in an interview.

He said the project adhered to standards from the Scientific Advisory Board, which is made up of climate experts, including in carbon cycling, oceanography, marine ecology, forestry and carbon sequestration. It was also reviewed by an independent science review board, he said.

Odlin said the process is safe as it is adding organic matter that could already exist in the ocean.

Shopify made the advanced purchase of the Running Tide removal credits in 2020 to help to fund the project's development.

“Funding innovation by being a first buyer, and taking big risks with pre-payments, is exactly what’s needed to kickstart the carbon removal industry,” said Kauk.

Shopify did not specify how much it paid for the removals. Running Tide said it currently charges $250-$350 a tonne.

(Reporting By Susanna Twidale; Editing by Jane Merriman)