I'm skeptical about efforts to rank and rate green or sustainable companies, and I have been for a time. [See 100 Best Corporate Citizens? What a CROck!] It's terribly difficult to compare big and small companies, retailers with manufacturers, software firms with oil companies, etc. We once tried at FORTUNE, and gave up because we decided it couldn't be done right.

Having said that, I'm impressed with the rigor and methodology used by a Canadian magazine called Corporate Knights to produce its 8th annual list of Global 100 Most Sustainable Companies, which it calls "the most extensive data-driven corporate sustainability assessment in existence." The ratings are transparent and they encompass social as well as environmental metrics, among them energy, carbon, waste and water productivity, diversity and employee turnover, safety and, interestingly, the ratio between CEO and average worker pay -- a revealing metric that most such rankings do not include.

A couple of things to note about the list. First, US companies perform poorly. There's not one US-based company in the top 10. Life Technologies (No. 15) is the highest ranked US-based firm, followed by Intel (18), Agilent (59), Johnson Controls (64), Procter & Gamble (66) and IBM (69). Lest you suspect a Canadian bias, our neighbors to the north did no better. The top-ranked Canadian firm was Suncor (48), which calls itself an "oil sands pioneer." Go figure.

Of the 22 countries with companies that made the list, the UK led the way with 16 Global 100 companies, followed by Japan with 11 and France and the US with eight. Northern European countries (Denmark, Netherlands, Norway, Sweden) punched above their weight, which isn't surprising.

Interestingly, these more sustainable companies have outperformed their peers. Toby Heaps, CEO of Corporate Knights, said in a news release: "In a year in which Wall Street was occupied and capitalism became a bad word, the Global 100 companies serve as ambassadors for a better, cleaner kind of capitalism which, it also turns out, is more profitable." The magazine reported:

From its inception on February 1 2005 to December 31, 2011, the Global 100 Most Sustainable Corporations has achieved a total return of 41.70 percent, outperforming its benchmark, (the MSCI All Country World Index at 29.30 percent) by more than 11 percent.

How did Novo Nordisk reach the top? According to Corporate Knights, the Danish pharmaceutical firm

is on record that access to essential medicines is a human right, and sells human insulin (the most basic kind) to 33 of the world's poorest countries, at no more than 20 per cent of the average price in the western world. On the key clean capitalism metrics measured by Corporate Knights, Novo Nordisk scored top quartile performance in energy productivity ($4,851 in revenue generated per unit of energy consumption, compared to a pharmaceutical sector average of $3,603), carbon productivity ($68,585 in revenue generated per unit of carbon emitted, compared to a pharmaceutical sector average of $56,414) and pay equity (CEO/average employee remuneration ratio of 15 vs. a pharmaceutical sector average of 93). Novo Nordisk is the only pharmaceutical company within the Global 100 to report linking CEO remuneration to corporate performance on clean capitalism KPIs.

What impressed me about Novo Nordisk was how deeply sustainability issues are woven into the fabric of the company. In my story, I write about the firm's approach to drug pricing, to climate and energy issues and to China. Here's how the story begins:

Don't ask Novo Nordisk for the company's corporate responsibility report. The Danish pharmaceutical firm, which had revenues of DKK 60.7 billion (US$10.5 billion) in 2010, doesn't publish one. Instead, Novo Nordisk reports on its environmental and social performance -- including water and energy consumption, waste reduction, employee turnover, the diversity of its management team, new patent filings and charitable donations -- alongside its financial performance in a single annual report.

This integrated approach to reporting reflects the way business is done at Novo Nordisk, the world leader in diabetes care and the No. 1 firm on the 2012 list of Corporate Knights Global 100 Most Sustainable Corporations. Novo Nordisk has pursued a triple bottom line of financial, social and environmental gains since the 1990s, when the phrase was coined by writer John Elkington, and it incorporated the concept into the company's legal structure nearly a decade ago.

"The main foundation for Novo Nordisk is the triple bottom line because that is what's protecting our license to operate," says Lars Rebien Sorensen, the firm's president and CEO. "That begs and obliges everybody in the company not only to see that we become a good business -- that's the financial bottom line -- but that we do so in a way that is socially and environmentally responsible."

Lise Kingo, who has worked on sustainability issues since joining Novo Nordisk in 1988, says the company's business case for corporate responsibility goes well beyond protecting its license to operate. Today, she says, the firm envisions sustainability as a way to drive innovation, and finds that engaging with stakeholders helps spot business opportunities as well as avert trouble. One sign of the value that the company places on sustainability is the fact that Kingo, 50, has been part of Novo Nordisk's five-person executive management team since 2002.

You can read the rest here.

And, speaking of rankings, I was pleased once again to be named to the Ethisphere Institute's 100 Most Influential People in Business Ethics. Lists are fun so long as we don't take them too seriously. (Really, how do you compare the influence of federal prosecutor Preet Bharara, Russian blogger Alexei Navalny and Walmart CEO Mike Duke, all of whom are in the top 15?) Still, some of the business people on the list whose work I know certainly deserve to be spotlighted, including Starbucks' Howard Schultz, Coca-Cola CEO Muhtar Kent, Jeffrey Swartz of Timberland, Brian Dunn of Best Buy, Yalmaz Siddiqui of Office Depot and Bob Corcoran of GE. I was also thrilled to see my friend Liz Maw, the executive director of Net Impact (where I'm on the board), be recognized for the great work that she, her staff and the organization are doing.

_{High-rise photo via Shutterstock.}