For Dianne Saxe, agitating for the public good may be a genetic trait. The new Environmental Commissioner of Ontario is the daughter of Morton Shulman, a crusading Ontario chief coroner in the 1960s who pressured the government into changing laws to make roads, boats and hospitals safer.

Dr. Shulman later became a member of the provincial Parliament, an author, television talk-show host, and a pharmaceutical entrepreneur. A successful CBC dramatic television series that aired from 1966 to 1968 – Wojeck – was loosely based on his work as an activist coroner.

Ms. Saxe may not have changed her spots as often as her father, but she has recently made an enormous shift of her own. Late last year, she gave up a successful private environmental law practice to take up the post of environmental commissioner in Canada's largest province. She is effectively the watchdog for the government, holding its feet to the fire to ensure policy and legislation on the environment, energy and climate is meeting its objectives.

She is intense and articulate – her legal training is obvious in her precise and detailed answers to my questions – but also soft-spoken. That's a bit of problem during our lunch in Mercatto, an Italian bistro on the ground floor of Toronto's MaRS technology incubator. The restaurant gets incredibly noisy over the course of our lunch, and by the end I'm straining to hear her amid the din.

But as she picks over her simple spaghetti dish, which she barely touches, Ms. Saxe, 63, patiently explains why she made the big leap into this job, a move that forced her to wind down her practice, while some of her staff and clients shifted to the environmental law group at Siskinds LLP.

At her law firm, Saxe Law Office, which she ran for 25 years, she handled disputes for hundreds of clients, over issues such as site contamination, water regulation and renewable energy. In one of her recent victories – where she represented the Association of Municipalities of Ontario – companies that make packaged goods and printed paper were forced by an arbitrator to contribute $115-million to the blue box recycling program. That was $20-million more than the firms wanted to pay.

While that case involved a broader public policy issue, a private legal practice is mostly a "retail" business that deals with individual problems of individual clients, Ms. Saxe pointed out. As environmental commissioner, she will get to look at the big picture, and "to make a bigger difference in things that matter," she said.

One of the commissioner's key roles is to issue reports on the effectiveness of government policy. The commissioner also oversees Ontario's Environmental Bill of Rights, which gives citizens a say in government decisions by providing tools for their input. In the past, public intervention has prompted changes ranging from better gravel pit regulation to the removal of restrictions on outdoor clotheslines.

Essentially, "the office has a chance to try and make the rules better at a larger scale," Ms. Saxe said.

Making a difference at a large scale is something her father certainly managed. Dr. Shulman pushed Ontario to put in place better rules to control a wide range of potentially dangerous activities. As coroner, he saw the bodies of people killed in car crashes, construction accidents and boating mishaps, Ms. Saxe said, and he was outraged at the carnage. He pressed for tougher life-jacket regulations in small boats, safer highway and car designs, breathalyzer tests, and a strict process to count surgical instruments before and after operations.

"There are obvious echoes with what I am trying to do," Ms. Saxe said. "What he showed was that if you change the rules, you can change the outcomes. Not with everything, but with some things."

Her passion for the environment also runs deep, engendered by her time spent at camp as a child. She cycles, loves canoeing, and hopes to paddle the Dumoine River in Quebec this summer.

Lawyer Paula Boutis, a former associate of Ms. Saxe who moved to Siskinds when the Saxe Law Office closed, said the new commissioner's broad experience dealing with people who have had to cope with environmental regulation makes her perfectly suited to the role. "Not only is she absolutely brilliant, and cares a lot about these public policy issues, she also brings those years of private practice experience where she can say: 'Here's where I think the government gets it wrong.'"

In private practice, Ms. Saxe did a lot of pro bono work and served on boards of environmental organizations, Ms. Boutis said. "She was always trying to find ways to use her skills to further the public agenda." And her former boss certainly has the needed energy level, Ms. Boutis added, describing Ms. Saxe as not just a "type A" personality but a "triple A."

But how does a provincial environmental commissioner force change, when there is no direct power to determine government policy?

It's a question Ms. Saxe has been asked many times since she got the job, and she has a rehearsed answer: "I have a flashlight, a can opener and a megaphone." Essentially, she said, her office – with a staff of about 45 people – has the tools to investigate and probe issues, and the soap box to report what she finds.

She will look at the government's objectives on environmental and energy issues, then monitor and evaluate how well they are meeting them. Her reports can point out if a policy isn't well designed, isn't well enforced, or conflicts with other policies. As Ontario moves to implement its complex new "cap and trade" plan to cut emissions, her watchdog position will be more important than ever.

"One of the things that I am most interested in, is where are the policy bottlenecks," Ms. Saxe said. She hopes to help clear these to ensure that rules and legislation do what they are supposed to do. It helps that the environmental commissioner is appointed by, and reports to, the provincial legislature, not to the government of the day – a crucial distinction that makes her more independent and able to criticize. (She applied for the job when it came open, and was selected by an all-party committee.)

Her predecessor as Ontario environmental commissioner, Gord Miller, was certainly willing to make waves. In reports issued during his 15 years in the job he slammed the government for failing to protect drinking water, denounced weak rules for importing toxic waste, pointed out that enforcement of pollution rules was ineffective, and recommended the province consider road tolls on highways.

One method Ms. Saxe may use to connect more directly with the public is to allow individuals to suggest topics her staff should examine. While the issues under scrutiny have traditionally been selected internally, "it strikes me that we might do better if we allow people to actually pitch us," she said. "There are smart people with good ideas out there. My staff are excellent, but they don't know everything."

The hard part will be to trim the choices. "After 40 years in this business, I am interested in a lot of things. My challenge is not to find an interesting topic. My challenge is to narrow it down among the many, many topics and find ones where there is a good reason for us to do it now," she said.

One key issue that will likely come into the beam of her flashlight is energy conservation in older buildings. There are vast numbers of homes, offices, and other structures in the province where retrofits could cut bills and reduce carbon emissions, she says. It may be useful for her office to look at the rules around energy audits, and draw attention to obstacles that might be getting in the way.

Her interest in this issue stems from personal experience at her synagogue, where faulty air conditioning left the building stifling in the summer. An audit showed the situation was "worse than terrible" she said, with an air conditioning duct disconnected in the attic, incandescent candle-lamps pumping out a huge heat load, and air leaking out of many holes in the building. "We changed the light bulbs, we reconnected the two ends of the hose and patched the holes in the roof, [which] we insulated. Bingo, suddenly you could stay awake on Saturday morning. And our bills went down."

While Ms. Saxe will provide neutral oversight, she is entering a political realm where her comments will be parsed and analyzed. Already, she has come under fire for musing about the value of existing tax exemptions on diesel fuel used for industrial purposes.

In a January interview with the Ottawa Citizen she questioned whether the design of this provincial subsidy was effective. Farmers, who are among those who get the break, reacted with fury at any suggestion they might be cut off. Ms. Saxe was forced to clarify her position, saying that she was merely asking whether there might be a better way to support farmers, because most of the diesel tax break goes to large companies that don't need it.

It was unfortunate and surprising "to have something so misinterpreted and cause so much concern," Ms. Saxe said, because she was merely "asking a question about hundreds of millions of dollars of public expense, which at the moment is used to subsidize diesel fuel consumption, very little of it by farmers."

Still, it is a reminder that people will be listening carefully when the new environmental commissioner speaks, Ms. Saxe acknowledges. "The position has gravitas, and I want to carry that well if I can."