BP Plc and Royal Dutch Shell Plc have hired an array of carbon-emissions traders to replenish their ranks after an exodus of staff to trading houses last year.

Competition for traders of so-called environmental products has ramped up over the past year, with firms such as Trafigura Group Pte and Mercuria Energy Group Ltd expanding their footprint in businesses related to the transition to clean energy. With the cost of emissions rising, commodity-trading houses have looked to BP and Shell to hire experienced hands in the world of carbon credits and offsets.

The two oil majors are active in emissions trading throughout the world. The buying and selling of so-called carbon offsets could be a large part of the firms net-zero plans, which include development of renewable energy as well as tree-planting and reforestation to absorb greenhouse gases emitted by the burning of oil and gas.

Among BP’s recent hires are Julia Elmgren, who joins from Gazprom Marketing and Trading Ltd., where she was head of environmental products, according to people familiar with the matter. Ex-BNP Paribas SA trader Jason Jurado has also joined the London-based company, the people said.

In Houston, BP has hired carbon trader Kellen Locke, who has spent the bulk of his career as an environmental trader for Koch Industries Inc., the people said. BP declined to comment.

Last year, BP lost a swathe of environmental-products traders to Glencore Plc’s offices in the Asia-Pacific region. That included Juan Carlos Parreno, who joined the commodity giant in December as a senior trader on its carbon portfolio, according to his LinkedIn profile. Glencore declined to comment.

Following departures from Shell’s carbon emissions desk in Singapore last year, the company has relocated senior liquefied natural gas manager Sameer Kotecha to take on the role of team leader for environmental products trading in southeast Asia and Oceania, according to people with knowledge of the matter. 

In London, the firm hired Beth Lang as a trader and originator for voluntary carbon markets in January from NEO Energy’s upstream unit. She started in January, according to her LinkedIn profile. Shell declined to comment.

Among the carbon traders the Anglo-Dutch firm lost last year were Sonia Battikh, who went to Citigroup Inc., and Kee-Nic Lee, who joined Trafigura’s carbon trading team in Singapore. Citigroup and Trafigura declined to comment.