Coal state Republican Rob Portman of Ohio plans to join the Senate's bipartisan climate change caucus, the Washington Examiner has exclusively learned.

Portman's office confirmed Thursday he will become a member of the Senate Climate Solutions Caucus, adding more Republican support to the first such bipartisan forum for senators to talk about climate policy. Portman follows the additions of Republicans Lisa Murkowski of Alaska, Mitt Romney of Utah, Lindsey Graham of South Carolina, Marco Rubio of Florida, and Susan Collins of Maine.

Republican Mike Braun of Indiana co-founded the caucus in October of last year with Democrat Chris Coons of Delaware. The group's formation comes as some Republican lawmakers are becoming more engaged in climate change policy discussions and polls show young and suburban voters care more about the issue.

Portman represents the third-largest coal-consuming state in the country, although natural gas has increased its share of the state’s electricity lately. It is one of the nation’s top emitters of carbon dioxide from the power sector and is the second-worst state in the country in terms of renewable electricity generation, which stood at 2.5% in 2018, according to the Energy Information Administration.

Portman, a relative centrist on many issues, has long supported some narrow policies to address climate change. Last year, he introduced bipartisan legislation to make it easier for power plants and industrial facilities to finance carbon capture equipment, along with a bill to incentivize energy efficiency in buildings, industry, and the federal government.

He is a member of the Roosevelt Conservation Caucus and Oceans Caucus and is a co-chairman of the Great Lakes Task Force.