(Reuters) - Is sustainability law the next hot practice area?

Or maybe I shouldn't say "hot" because, well, climate change. But law firms increasingly see a major opportunity to help clients with a host of environmental, social and governance, or ESG, matters.

I'm always a bit skeptical when law firms en masse tout the next big thing—I'm old enough to remember when everyone was sure Y2K litigation was going to be huge.

But the growing focus on ESG matters seems to be here to stay.

Major firms including Covington & Burling; Paul, Weiss, Rifkind, Wharton & Garrison and Latham & Watkins formally launched ESG practices this year, following peers including Kirkland & Ellis; Akin Gump Strauss Hauer & Feld; Norton Rose Fulbright and Shearman & Sterling, to name just a few examples.

The issues don't tend to fit neatly in a single practice area, but for some firms, that's actually an advantage.

Covington, for example, in August formed a 100-lawyer, cross-disciplinary "sustainability solutions" team, in what may be the largest such ESG Big Law undertaking.

The firm has no billing or origination credits, which means there's no "What's in it for me?" hurdle to collaboration, said partner Kevin Poloncarz, a member of the sustainability team.

"The net result is that partners are willing to participate in an effort to broaden the scope of the work they're doing without worrying about who gets credit," said Poloncarz, who co-chairs the firm's environmental practice group and energy industry group.

At 1,300-lawyer Covington, that means litigators, regulatory specialists, corporate and M&A partners are combining their expertise to help a wide swath of firm clients manage ESG challenges.

Such issues affect "all industries, all the firm's clients," said W. Andrew Jack, a member of the sustainability team and co-chair of the firm's energy industry group.

The firm lays out eight primary areas of focus: carbon reduction; corporate governance; disclosure; digitalization and data; environment protection and resource conservation; human rights and social justice; product and consumer responsibility; and sustainability transactions.

You don't have to be a law firm marketing genius (I'll refrain from making an oxymoron joke) to see the potential demand for such services.

Consider BlackRock's annual client letter. Last year, the world's largest asset manager in its widely anticipated missive made the barest of passing nods to "environmental risks and opportunities."

This year, the entire letter was about sustainability, which BlackRock proclaims is its "new standard for investing … integral to the way BlackRock manages risk, constructs portfolios, designs products, and engages with companies."

So hello, yes, there's clearly an opening here for lawyers to offer guidance to corporate entities now being held more accountable by investors and customers.

One of the first law firms to plant an ESG flag was Akin Gump Strauss Hauer & Feld, launching its practice in September 2015.

Partner Stacey Mitchell explained that ESG was originally part of the firm's international trade group "because of touch points in international trade through, for example, conflict minerals reporting requirements," but it has broadened the group to 38 lawyers and advisors across the firm.

Norton Rose Fulbright was another early trend-spotter, forming its 20-lawyer ESG team in 2017. Partner Bob Comer said the 3,700-lawyer firm's "global perspective meant that we saw these issues developing and growing in importance across multiple industries and different jurisdictions."

At Latham & Watkins, about 45 lawyers are part of the firm's core ESG task force, which was formalized earlier this year, according to partners Paul Davies and Ryan Maierson.

"We have seen a huge surge in interest in ESG issues over the last couple of years starting with our banking and investor clients and now extending well into our corporate client base," they said in an email.

At Kirkland & Ellis, the 20-lawyer sustainable investment and global impact practice group was formally organized last year, according to Alexandra Farmer, a leader of the group—though she notes many more lawyers are involved in offering advice on related issues.

Likewise, Shearman & Sterling global managing partner George Casey said the firm has fielded a "cross-practice and multi-jurisdictional team" to advise on ESG issues,

Casey said firm lawyers "regularly advise clients on the full spectrum of ESG matters, advising boards on developing ESG strategy, working with management in developing day-to-day policies and procedures, creating ESG disclosure frameworks, and advising on impact investing and human capital management."

When Paul Weiss launched its sustainability and ESG advisory group in April, the firm brought in former litigator and business executive David Curran as chief sustainability and ESG officer to manage the practice.

The team is helping clients stay consistent in their ESG messaging, coordinating everything from investor relations to public relations to legal advice, Curran said, adding that it "can be a very fragmented ecosystem of resources."