At Tuesday's Business Insider GOP primary debate, two of President Donald Trump's Republican primary challengers, former Rep. Joe Walsh and former Gov. Bill Weld, argued that the Republican Party needs to take the issue of climate change seriously.

This past week, young environmental advocates from both sides of the aisle also spoke before Congress encouraging them to take action on lowering emissions and fighting the effects of climate change.

August polling from the firm Glocalities, based in Amsterdam, found that 67% of Republicans aged 18-34 are concerned about human-made climate change.

Walsh said, "This is the issue that concerns most young Americans ... I've acknowledged that it's real."

Both candidates also argued in favor of relying less on foreign oil and investing in nuclear and renewable energy solutions, including wind and solar.

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At Tuesday's Business Insider GOP primary debate, two of President Donald Trump's Republican primary challengers, former Rep. Joe Walsh and former Gov. Bill Weld, argued that the Republican Party needs to take the issue of climate change seriously.

This past week, environmental activists, including 16-year-old climate activist Greta Thunberg, participated in climate strikes all around the world protesting world leaders' inaction on human-driven climate change.

Thunberg and other young environmental advocates from both sides of the aisle also spoke before Congress encouraging them to take action on lowering emissions and fighting the effects of climate change.

Walsh said, "This is the issue that concerns most young Americans ... Republicans have to acknowledge that it's real."

During his 2016 campaign, Trump promised to save the coal industry and introduce "clean, beautiful" coal — which doesn't exist — as an alternative.

The Environmental Protection Agency and the Interior Department have also moved to gut hundreds of environmental and public lands protections under the Trump administration, but it could hurt them among young voters.

Read more: WATCH LIVE: Business Insider Today's Republican presidential primary debate with Gov. Bill Weld and former Rep. Joe Walsh

August polling from the firm Glocalities, based in Amsterdam, found that 67% of Republicans aged 18-34 are concerned about human-made climate change.

Another young activist who testified at the hearing was Benji Backer, who founded the American Conservation Coalition,a group that advocates for free-market and bipartisan solutions to climate change.

Weld, who calls himself an "environmentalist" and favors government regulations to protect the environment, spoke in favor of one such solution in the form of a carbon tax on emissions, which he argues would incentivize businesses to cut their emissions.

Both candidates also argued in favor of relying less on foreign oil and investing in nuclear and renewable energy solutions, including wind and solar.