It’s Infrastructure Week in Washington, D.C., and thousands of leaders from business, labor and government have converged on the city. They’ve come to ask Congress to invest in the unglamorous but essential systems of modern life — including transportation, clean water and the electric grid.

Their mission is critical: Our nation’s infrastructure earned a grade of D+ from the American Society of Civil Engineers in 2013. Across the country, crumbling bridges and failing water treatment plants pose a real threat to public health and safety and a drain on economic growth.

And that’s on a good day. As climate change unfolds, our nation’s infrastructure must also withstand increasingly frequent extreme weather events. A recent analysis by the Center for American Progress found that, over the last four years, 42 of the most costly weather events triggered $227 billion in economic losses across 44 states.

That’s why President Obama made community preparedness a key pillar of his Climate Action Plan. In March, the President requested some $90 billion for FY 2016 to reduce disaster costs by strengthening community and infrastructure resilience.

If Congress fails to appropriate these funds, the economic and human costs of disasters will continue to rise. And, while no communities will be completely spared, history shows that the greatest cost will be paid by those who can least afford it.

From urban centers to rural and tribal lands, low-income communities are extraordinarily vulnerable to extreme weather. They are often located in low-lying areas, where failing infrastructure and poor-quality housing are readily destroyed by storms. Toxic waste sites, landfills and coal-fired power plants, which pose added threats when disaster strikes, are often located in or near those same communities. Where people live paycheck to paycheck, lost work days can push families into destitution.

But, by making the right investments, we can strengthen our infrastructure to withstand climate change and share burdens and opportunities more fairly. For example, governments can:

• Expand public transportation, and make sure it is accessible to low-income communities. Public transportation increases access to good jobs, and helps people out of harm’s way before a disaster. (Bonus: Public transportation also reduces carbon emissions, which can mitigate the threat of climate change.)

• Invest in quality affordable housing that keeps families safe during extreme heat and storms.

• Design community resilience plans that protect the most vulnerable, and give low-income communities and people of color a seat at the planning table.

Across the country, forward-thinking local governments are working to reduce extreme weather risks in low-income communities. Seattle has made equity a core principle in its climate preparedness plans. By building relationships with community-based organizations, city officials are engaging residents in the planning process. Similar efforts are underway in New York City, Portland, Oakland and Berkeley.

These local efforts are vitally important. At the same time, federal investments in infrastructure offer an opportunity to bring this work to a national scale — to build climate resilience and equity into the bedrock of our communities for decades to come.

So, here’s something for members of Congress to think about during Infrastructure Week. Yes, we must repair our failing infrastructure by investing in state-of-the-art transportation, water and power systems. But — to meet the challenges of the 21st century — those systems must also withstand the extremes of a changing climate. And they must protect the most vulnerable, while building opportunity for all.