"There's no question that that we have to come back with a lot of eating a lot of humble pie," she told ABC News' Chief Meteorologist Ginger Zee, saying the U.S. has not been engaged with our allies the last four years.
But she said other countries want the U.S. back at the table.
"They know the leadership that we can provide, and as long as we continue to listen to them and learn from some of the work they're doing, I think we'll do just fine," McCarthy said.
President Joe Biden has said he plans to push other world leaders to amp up their commitments to reducing carbon dioxide emissions to combat climate change. His special envoy for climate, former Secretary of State John Kerry, has traveled to countries like India, China and the United Arab Emirates ahead of the summit to talk about their climate goals.
McCarthy, who formerly worked as head of the Environmental Protection Agency under President Barack Obama, said Biden understands the country can tackle climate change domestically while also boosting the economy and that the solutions can benefit everyone, including communities that have been disproportionately impacted by pollution.
"We do have a leader that understands that this is an intersectional issue," she said, adding that the pandemic, economic development, climate change and racial issues are all intertwined.
McCarthy said Biden's infrastructure bill and economic plans will create jobs and help the country reach its climate goals through avenues like retrofitting older homes to be more energy efficient and increasing electric vehicle production. She said the federal government can lead the way by prioritizing climate solutions that will build momentum for those efforts.
"You have to send the signal at the federal level about where we need to go and what values we need to apply to those decisions. And then when we do, we go to the 10-yard line. All of a sudden, the next 10 happens because the private sector starts investing because they know you can't go back. And I think climate change is exactly that type of issue," she said.
"We'll get the ball rolling," she continued. "We'll work internationally with Sec. Kerry when the summit happens. And I think President Biden's plan is going to deliver the momentum we need to really get across the finish line."
ABC News' DJ Cunningham contributed to this report.