In 2016, oil companies are more concerned with their public images than ever before, especially pertaining to the environmental impact of their operations. Under pressure from the U.S. Department of Energy, the Office of Fossil Energy, consumers, activists and shareholders, many oil companies have invested in renewable energies or altered their procedures to "stay green."

The oil companies that have done the most to protect the environment include Exxon Mobile Corporation (NYSE: XOM), Sunoco LP (NYSE: SUN), up-and-coming Canadian firm MCW Energy Group Limited, and even the much-maligned BP PLC (NYSE: BP).

BP PLC

Prior to the terrible Gulf of Mexico oil spill in 2010, BP, then called British Petroleum, was considered a very progressive company on climate change and alternative fuel research. BP has a long track record of operational transparency, and it routinely publishes sustainability reports. Even before its much-needed public relations campaign after the Gulf disaster, BP was championing its efforts to move "Beyond Petroleum."

BP has pumped money into solar, wind, hydrogen, and other biofuel technologies. It's one of the largest renewable donors in the world. In its annual oil company rankings, activist group Greenopia placed BP in first place in 2008 and 2009.

According to BP's press releases and company website, the European oil giant is engaged in water cleanup, greenhouse gas reductions, building more efficient technologies, and it is "working to minimize the controlled burning of gas, known as flaring." In terms of past performance, BP's spill stands out as a major wart; in terms of present activity, BP is very active when it comes to environmental protection.

MCW Energy Group

According to Paul Davey, communications officer for MCW, this Toronto-based fuel distributor started looking at different ways to process oil sands in 2010. It opened an oil facility in Utah in 2014, using a cheaper process than its industry rivals and what the company describes as "benign chemicals" to separate oil from sand.

MCW uses its action plan, dubbed "Health, Safety & Environmental Management System," which has been designed in conjunction with the environmental consulting firm JBR Environmental. According to both groups, the process "requires no water, no high temperatures/pressures, and there are no greenhouse gases produced. It's a closed-loop system." MWC also works with the Utah Institute For Clean & Secure Energy.

Sunoco

Major environmental advocacy groups, such as the Sierra Club, list Sunoco as a favorite oil company. The Pennsylvania-based Sunoco is the only oil company to endorse the so-called Ceres principles, which include reducing overall emissions, promoting sustainable uses of natural resources, conserving energy, and taking "responsibility for any harm caused by our operations to our employees, customers, the general public or the environment."

Still, for all of its press and proclamations, Sunoco has spent less on environmental projects and research than many other major oil companies.

Exxon Mobile

Exxon Mobile has an extended pro-environment history. In 2006, the company introduced the "Protect Tomorrow. Today" agenda, which it described as a framework to improve operational efficiency, fuel efficiency, and develop breakthrough technologies.

The next major step was a nearly $100-billion investment in biofuel research in 2009. Even though the research eventually found biofuels weren't economically sustainable yet, it was one of the largest private investments ever in the alternative energy space. For its efforts, Exxon claimed the "Green Company of the Year" title from Forbes.

Each year, Exxon emphasizes its dedication to helping reduce greenhouse gas emissions and support research. According to company claims, Exxon's drill rate has improved 80% since the launch of "Protect Tomorrow. Today."

More to Do

Major oil producers can't rest on these advancements, even if only for green marketing or public relations reasons. The majority of Americans view companies negatively. In 2015, Greenpeace spokesman Travis Nichols told CNBC, "There are no oil companies we would trust to bring us to a renewable energy future."