OPINION In pursuit of ambitious climate, renewable energy and clean air goals, state environmental leaders should leverage the central role of advanced diesel technology. They should consider its new capability to deliver less greenhouse-gas emissions, cleaner air, and reliable and essential services in both the public and private sectors.

The pace of the energy conversation is such that it’s easy to be confused about which fuels technologies are working today, and those that may hold promise and might be coming in the future. When it comes to diesel there are no “mays” or “mights” or “maybes.” There’s only a proven track record, ever-increasing efficiency and a new generation of near-zero emissions technology. The newest diesel engines can be found in applications such as public transit and school buses, first-responder vehicles, commuter and freight rail, snow-removal trucks, waste and refuse service vehicles, commercial trucks, emergency backup power generators, ferry and tug boats, construction equipment, microgrids and more.

Almost everything about diesel technology has changed in the past decade, ensuring its place in the future. Today’s diesel engines deliver more proven benefits to both customers and society at large by using less energy, achieving near-zero emissions performance, and increasingly using use lesser-carbon renewable biofuels. What hasn’t changed is diesel’s fundamental durability, reliability, efficiency, economical ownership and operation, as well as expansive service and fueling networks, and performance. Those key factors ensure diesel remains a proven asset, delivering the level of public and private services our growing economy demands.

Today you might say we are straddling the worlds of energy abundance and the clean-energy future in both the public and private sectors. The unique prospect for diesel is that it has a foothold in each.

The newest generation of diesel engines, deployed in conjunction with ultra-low-sulfur diesel fuel, offer a proven cost-effective, energy-efficient, near-zero-emission power choice. Currently almost 40 percent of all new commercial trucks on the road nationwide are powered by the newest advanced engines.

When paired with advanced renewable biodiesel fuels, new and existing diesel engines in commercial vehicles as well as farm and construction equipment and other vehicles deliver immediate greenhouse-gas-emissions reductions across the entire fleet without any investments in new fueling infrastructure or vehicles. Cities in California such as Oakland, San Francisco, Sacramento, San Diego, San Benito County and others now exclusively use renewable-diesel fuel in city-owned heavy-duty trucks, buses and equipment. They reap the benefits of cost savings and emission reductions. The San Francisco Metropolitan Transportation Agency uses renewable-diesel fuel in 632 transit buses, reducing emissions by more than 10,000 tons in a single year.

State environmental leaders are faced with delivering day-to-day environmental and public-health compliance and protection, as well as accommodating shifting political and other external influences. We should all embrace innovation and explore opportunity. But we should not at the same time lose sight of technologies like diesel engines that deliver climate progress today on a wide scale. In many sectors no other fuel or technology is expected to be capable of delivering substantial cost-effective benefits on the same scale for the foreseeable future.

Many would be surprised to know that in California it’s the use of biodiesel and renewable diesel fuel – not electrification or natural gas – which is the primary means by which the state is achieving its lesser-carbon transportation fuel mandates, as well as its progress toward the global climate action plan. By 2030 black-carbon emissions attributable to diesel engines in California – a short-lived climate pollutant – will be almost eliminated. That’s thanks to the introduction of the newest generation of diesel technologies, not due to fuel switching or diesel replacement.

The work of the Diesel Technology Forum during the past year has highlighted new findings that illustrate the progress between older-generations and newer-generations of diesel technology. Research evaluating the cost-effectivity of replacing older generations of marine and locomotive engines with the latest-generation clean-diesel models showed us the overwhelming clean-air benefits that can be achieved. Research also showed such upgrades are often the cheapest option. That same research also identified that in some ports, the service lives of those large marine engines far exceeds that of the present models. The research presents new insights and opportunities for state leaders seeking immediate clean air and greenhouse-gas-emissions benefits.

In many state and local governments, the existing fleets of diesel-powered vehicles and equipment have been in continuous service for decades. Most of those older engines do not incorporate the most effective emissions-control technologies. Prioritizing a step-change upgrade for such equipment to the newest-generation diesel engines represents the fastest most cost-effective way to deliver cleaner air and emissions reductions. Those benefits become even more striking when new engines are paired with clean advanced biofuels, which cut greenhouse gasses and other emissions even further.

Allen Schaeffer is the executive director of the Diesel Technology Forum, a non-profit organization dedicated to raising awareness about the importance of diesel engines, fuel and technology. Forum members are leaders in clean-diesel technology and represent the three key elements of the modern clean-diesel system – advanced engines, vehicles and equipment; cleaner diesel fuel and emissions-control systems. Visit www.dieselforum.org for more information.