(Reuters) — Royal Dutch Shell P.L.C.’s boss said it would be "foolhardy" for the oil and gas producer to set hard targets to reduce carbon emissions as it risked exposing the energy giant to legal challenges.

The energy industry has struggled in recent years to find a clear path to secure its role as the world shifts from fossil fuels in order to meet the 2015 Paris climate agreement goals.

Shell Chief Executive Officer Ben van Beurden last year set out ambitions last year to halve its carbon emissions by 2050, far exceeding rivals. But the Dutch CEO resisted calls by activists and some investors to set binding targets.

"It would be somewhat foolhardy to put ourselves in a legal bind by saying these are the targets we will adopt," Mr. van Beurden said at a company event.

"Before we put ourselves at the mercy of a legal challenge, I want to make sure we are doing the right thing first."

Mr. van Beurden, a vocal proponent of the world's need to meet the Paris goals, urged investors to trust him.

"You have to believe us that setting an ambition, sticking my neck out, my personal reputation, the reputation of the company, is a big enough incentive to get it right," he told reporters.

More lawsuits

Oil companies have faced a growing number of legal challenges over climate change in recent years.

On Monday, Rhode Island sued several major oil companies, including Exxon Mobil Corp., Shell Oil Co. and BP P.L.C., accusing them of contributing to climate change that is damaging infrastructure and coastal communities.

BP this year announced plans to keep carbon emissions from its operations flat until 2025. But BP CEO Bob Dudley echoed Mr. van Beurden's concerns at the company's annual general meeting in May and refused to disclose details of the plan.

"You want to get us to make statements here in front of you that you can document that will lead to a class action," Mr. Dudley said in response to a question from a shareholder.

Shell spends the most among the world's top oil and gas companies on low-carbon energies, investing up to $2 billion per year in renewables and clean fuel technology, out of a total spending budget of $25 billion to $30 billion per year.

"It is more sensible to say we will go faster than society, we will catch up with society on its way to meeting Paris," Mr. van Beurden said Thursday.

"It is a very clear ambition, we will articulate this ambition in steps as we go along the way. We will be totally transparent."