This article was originally posted to the Huffington Post.

The world community is rightfully celebrating today’s enactment of the 2015 Paris climate agreement as a landmark achievement in the fight against climate change. The truth is that this day – Nov. 4, 2016 – could ultimately be remembered as an historic turning point, or it could become another footnote in a losing battle against warming.

To be clear, the Paris agreement is an excellent plan – calling for nations to take the necessary steps for keeping global temperature change to “well below” 2 degrees Celsius. Uniting nearly 200 countries of widely varying political and economic conditions around the treaty was a monumental achievement.

But the true success of the effort will hinge on execution, and on the concrete actions countries take moving forward. There are difficult decisions to be made in the shift from a carbon-based economy. There are also simple things we can do immediately, without sacrifice, and it starts with increased energy efficiency. The U.S. can and should lead the way, beginning with Congress.

While people can disagree on the steps needed to address climate change, we should all agree that being more efficient and productive with the energy we use is good for our economy, energy security and environment. Whether it’s improved standards for refrigerators and dishwashers or stronger building codes for structures that better hold heat and cooling, many of the policies we need are common-sense, bipartisan updates to outdated regulations. They usually save consumers money right away through lower electric bills, have strong industry support, and create jobs even as they cut emissions.

And don’t think this is just feel-good tinkering around the margins. The impact of efficiency in reducing harmful emissions is unrivaled: According to the International Energy Agency (IEA), improved efficiency is the single most effective tool we have for reaching our goals, and it can be as much as half of the solution.

Further, it can be done with tremendous benefits for consumers. Think about the appliances and equipment around your house – refrigerators, air conditioners, dryers, etc. Efficiency standards implemented since 1987 for those products alone have reduced carbon dioxide emissions by 3 billion tons according to the Department of Energy. That’s equivalent to the annual emissions of 631 million automobiles.

Meanwhile, the same standards are saving the average American household $319 per year on energy bills, even as appliances have evolved with more features and capacity, and typically cost less than they did decades ago.

The good news is Congress is on the cusp of taking a major step forward. Earlier this year, the Senate – in an overwhelming show of bipartisanship rare in today’s Congress – voted 85-12 to pass the Energy Policy Modernization Act. The bill’s lead section is an energy efficiency title led by Sens. Rob Portman, R-Ohio, and Jeanne Shaheen, D-N.H., that would promote smarter building codes, provide new efficiency incentives, and ensure the U.S. continues to lead the world in efficiency innovation.

House and Senate lawmakers are working to finalize the legislation before year’s end, and if leaders can set aside partisan maneuvering, Congress has a narrow window of opportunity to make it the first major energy legislation to become law in a decade.

Regardless of one’s views on the urgency of climate change, conservatives and liberals alike should rally around the Portman-Shaheen provisions, and around the larger movement toward increasing our energy productivity. Every year we wait is another year of higher utility bills, lost opportunities for jobs, and unnecessary pollution.

Our friends at IEA said it well in a recent report: “As the world transitions to clean energy, efficiency can make the transition cheaper, faster and more beneficial across all sectors of our economies. Indeed, there is no realistic, or affordable, energy development strategy that is not led by energy efficiency.”

As policy makers around the world seek to make good on their climate commitments, the first option should be tapping fully into the most abundant, cheapest, and cleanest resource for powering the global economy: energy efficiency.

Callahan is president of the Alliance to Save Energy, a nonprofit, bipartisan alliance of business, government, environmental and consumer leaders advocating since 1977 for enhanced energy efficiency across all sectors of the economy.