At 8:27 a.m. on Monday morning, May 23, Caroline Dennett emailed 1,400 executives at the oil and gas conglomerate, Shell, to announce her resignation after 11 years working as a safety consultant.

Dennett, who is based near London, asked executives and management at Shell “to look in the mirror and ask themselves if they really believe their vision for more oil and gas extraction secures a safe future for humanity.”

Dennett later posted a screenshot of her resignation email, a one minute and 12 second video in which she speaks directly into the camera explaining her decision, and a written explanation of her decision on the professional networking site LinkedIn.

In the time since, her LinkedIn post has gotten almost 10,000 reactions and more than 800 comments, some supportive of Dennett and some supportive of Shell.

Her market research business, Clout, started working with Shell in 2011 after BP’s 2010 Deepwater Horizon spill in the Gulf of Mexico ushered in a new emphasis on safety precautions throughout the oil and gas industry. She was brought on to design, pilot and manage surveys of workers to get a sense of how rigorously safety precautions were being followed. With the information collected, Dennett would make recommendations on how to improve the culture surrounding safety among workers.

Dennett did not take the decision to stop doing business with Shell lightly.

“The nerves came when I decided to do it, which was probably a few weeks before, and I’ve mulled it over for a few months to be honest,” Dennett told CNBC on Tuesday. “You don’t make a decision like that very rashly. It’s something you have to consider.”

But ultimately, Dennett says, she could not continue to work for Shell because of the contradictions she observed between the company’s attention to the safety concerns of individual workers on location and the fundamental danger of continuing to extract oil and gas and burn it for energy.

Shell’s internal safety program is dubbed “Goal Zero” and its aim is to have “no harm and no leaks,” Dennett said.

“The Goal Zero is honorable, but they don’t equate that to the harms that are being done on a massive scale. It’s great to keep individual people safe and try to prevent leaks that cause pollution and environmental problems, but if your very core of your business is pumping CO2 into the atmosphere at a rate that we know can not be sustained, we can not go on doing that in the way that we have done for the last 30 years,” Dennett told CNBC.

“Something is wrong with that.”

If Dennett thought Shell were making a good-faith effort to transition away from carbon emitting energy sources to clean energy sources, she says she would have stayed.

But that was not what she observed. To the contrary, Dennett was asked to reformat a safety survey to be able to use it for new projects to build pipelines and rigs. And that is when Dennett decided what she was seeing was “not right,” she told CNBC.

“It wasn’t just those two projects. I knew that there were more coming down the line,” Dennett told CNBC. “There were going to be another four, five, six, seven.”

The second reason Dennett says she left was because climate change was not discussed internally.

“We have all that surveying data, all that opportunity for people to give open feedback, and they do — tens of thousands of words on safety. Very little conversation on climate change, or anything like that, and environmental issues, beyond knowing there’s pollution in the local community,” Dennett said.

“And you just think, why is that not happening? Probably in the PR department, and the marketing department and the brand communications department, I suspect they talk about nothing else but how they can make themselves appear as a more sustainable company. But if that conversation is not happening at the operational front line, then that says that’s not the culture.”

Shell has a new energies portfolio and Dennett has done work with that division. But they’re more of a side project in Dennett’s view.

“It’s not very real,” Dennett said. The smaller acquisitions, like that of a German battery company, for example, “felt like window dressing, to be honest.”

Shell told CNBC that it is committed to its decarbonization goals.

“Shell remains determined to deliver on our global strategy to be a net zero company by 2050, and thousands of our people are working hard to achieve this. We have set targets for the short, medium and long term, and have every intention of hitting them,” the company said. “We’re already investing billions of dollars in low-carbon energy, although the world will still need oil and gas for decades to come in sectors that cannot be easily decarbonized.”

Shell is not Clout’s only customer. And Dennett knows she is in a position of privilege in being able to decide to terminate her contract with Shell.

“I know there’s people who are at the front line in those industries, they don’t have a choice. They really don’t have a choice — it’s oil and gas or bust,” Dennett told CNBC.

In Europe, North America and some other regions, there are places for skilled workers to find employment, especially if they have engineering skills or other technical skills.

“But in places like Nigeria, there isn’t really a lot else and the local communities have been so decimated by pollution that the traditional kind of farming and fishing work is very, very limited,” Dennett told CNBC. “You could maybe go to another oil and gas player, but it’s the same, just jumping from one to the other.”

Ultimately, Dennett hopes Shell leaders hear her message.

“They’re a powerful company that could be doing so much good in the world,” Dennett said. “It’s such a shame, they have all the capacity and the power to do that. I just really wish they’d have a vision and a strategy for the future that doesn’t involve dodging climate risks.”