The city that brought the world PlaNYC and Mayor Bill de Blasio’s commitment to cut carbon emissions 80% by 2050 is unquestionably ahead of the pack when it comes to combating climate change. And in New York City that effort must begin with buildings, which account for 70% of our greenhouse gas emissions.

But even if we’re out front, there are still lessons to be learned.

That’s why Urban Green Council has released Worldwide Lessons, which takes an in-depth look at what New York can learn—and borrow—from green building practices in five major cities around the world: Sydney, San Francisco, London, Frankfurt and Singapore.

Although not exhaustive, this sampling covers a wide range of political and economic environments. Looking at green building best practices in these peer cities, we’ve identified several major opportunities to advance our already impressive sustainability blueprint.

First, we need to improve how our energy code works. Imagine if cars had mandates for vehicle weight and engine size rather than for fuel economy. Unfortunately, that is the approach taken by New York (and most American cities) to buildings. Frankfurt, London and San Francisco regulate overall emissions or energy use. In New York, codes are based on energy cost, so the price of fuel influences design decisions. Even high-performing buildings must follow strict rules that regulate individual building elements, which complicates design. It’s time for New York to consider moving to a performance-based metric that simplifies compliance.

Second, the city should pursue issuing grades for buildings' energy efficiency like we do for restaurants' food safety. This would be the next logical step for the city's building benchmarking program, making it more powerful and accessible. A good example is London, whose labeling program drives tenant demand for energy-efficient buildings.

Finally, the city and industry should emulate Frankfurt and explore a formalized approach to training and certifying its construction workforce. It would focus on the skills and awareness needed to create, renovate and maintain efficient and sustainable buildings. At Urban Green, we’ve begun this work through our national training program, GPRO, which teaches principles of sustainability and trade-specific green construction to experienced building professionals.

This is far from an exhaustive list of steps the city and real estate industry can take to green our buildings. But, looking around the world, these are some of the biggest opportunities we identified.

Climate change doesn’t care where carbon dioxide comes from. And we all win when cities reduce their emissions. But competition in the global real estate industry—and good old New York City chutzpah—mean we should stay in the lead. Sometimes there's no greater competitive advantage than the ability to learn. Worldwide Lessons can help New York City keep its edge.

Russell Unger is executive director of Urban Green Council, the New York affiliate of the U.S. Green Building Council.