Peter Krull’s book “The Sustainable Investor” ( Wiley, November 4 2025 ) arrives at a critical moment for global finance, when the debate over sustainability and environmental, social and governance ( ESG ) investing has shifted from moral aspiration to market necessity.

Krull, partner and director of Sustainable Investing at Earth Equity Advisors, makes a compelling case that sustainability is not philanthropy, it’s sound investment strategy.

As an author, Krull has longevity in the field of sustainability, having been in the industry for 20-years, which is important in a sector where many voices are newer. He also holds professional credentials, has been publicly recognized with awards and is engaged in industry discourse ( podcasts, media, speaking ), rather than just practicing quietly. Also, his focus on avoiding greenwashing and values alignment resonates with many investors and advisers who are distrustful of superficial ESG claims.

In his book, Krull calls traditional index investing “rear-view mirror investing … about where the economy has been”, whereas sustainable investing “is where the economy is going”.

That future-oriented stance defines the book’s central premise: investors who align their portfolios with sustainability trends are positioning for structural growth, not virtue signalling.

Krull traces the evolution of socially responsible investing from early faith-based exclusions to the modern, data-driven ESG framework. “ESG is not charity; it’s foresight applied to capital,” he writes, summarizing two decades of experience helping clients transition from ethical alignment to strategic sustainability.

The author draws an important distinction between portfolios that are merely “less bad”, meaning those that reduce exposure to high-carbon industries, and those that are truly sustainable. “An ESG portfolio that reduces its exposure to ExxonMobil is less bad,” Krull says. “One that eliminates it entirely is better. But one that replaces it with First Solar [America’s largest solar manufacturer] is actually sustainable.”

His emphasis on “solutions-based portfolios” captures his conviction that investors should actively fund the next economy, not just divest from the old one.

For North American investors, this book is an excellent foundation: accessible, pragmatic and clearly argued. But for institutional investors operating in Asia, from Singapore’s established markets to China and India’s evolving frameworks, Krull’s Western-centric approach feels like a strong philosophical starting point rather than a comprehensive playbook.

Asian translation needed

Where Krull’s arguments resonate most in Asia is in his treatment of governance, the “G” in ESG. He views governance as a direct proxy for risk management, a perspective that mirrors the approach of many Asian regulators and asset owners.

The Monetary Authority of Singapore’s efforts to curb greenwashing through clearer fund labelling, for instance, reflect the same belief that governance drives credibility and long-term performance.

Asia’s concentrated corporate ownership structures, state-owned enterprises, chaebols and family-controlled conglomerates pose distinctive governance challenges: related-party transactions, opaque succession plans and minority shareholder risks.

Krull’s advocacy for active stewardship over exclusionary screening aligns well with these realities, even if his book doesn’t fully explore them.

Implementation gap

Krull champions transparency and standardized ESG reporting, but implementation in Asia remains uneven. While Japan is aligning with global standards under the International Sustainability Standards Board, other markets are still developing local disclosure rules at varying paces.

This fragmented landscape means investors cannot rely on a single ESG score or framework. Instead, they must navigate multiple reporting regimes and fill data gaps, particularly in fixed income and smaller-cap equities.

Here, Krull’s book could have gone further because, for Asia-based investors, ESG integration is less about abstract “values alignment” and more about data procurement, localization and regulatory adaptation.

Krull’s treatment of the social and environmental pillars also leans heavily on US examples, such as income inequality, domestic energy transition and demographic shifts, which resonate less in an Asian context.

In this region, social factors often define material risk. For example, migrant worker welfare, supply-chain labour practices and community displacement remain central to corporate resilience.

For many Asian investors, climate change is not an abstract concern but an existential one. The Philippines, Bangladesh and Indonesia face rising climate vulnerability that demands integrated, localized solutions.

Krull’s framework provides the philosophical tools for these discussions, but stops short of operational guidance.

Moral voice with market logic

Despite its US focus, Krull’s voice carries authenticity. He compares investing choices to everyday consumption decisions: “When you go to the store do you buy the organic product or the conventional one? [… ] If you’re going to do this, why not do it so that you not only have an impact on somebody’s bottom line, but you also have an impact on the world around them?”

That metaphor captures both his accessibility and conviction, blending personal ethics with portfolio pragmatism. It’s the kind of messaging that resonates with investors seeking both moral clarity and measurable results.

Foundation versus adaptation

“The Sustainable Investor” succeeds brilliantly in explaining why ESG matters and in dispelling the myth that responsible investing means sacrificing returns.

However, it is less effective at showing how those principles can be localized in Asia’s complex, fast-evolving markets.

For Asian institutional investors, the book should be seen as a foundation rather than a manual, a “why” that needs a regional “how”. Building upon Krull’s principles will require customized governance engagement, data localization and sensitivity to region-specific social challenges.

Krull’s message is universal – sustainability is the economy of the future. However, in Asia, realizing that vision will depend on how deeply investors can translate his ideals into their own diverse realities.