State Sens. Josh Green and Will Espero launched campaigns this week for lieutenant governor in the 2018 election.

Green, 47, is an emergency room doctor at Kohala Hospital on the Big Island. He was elected to the House in 2004 and then to the Senate in 2008. He has played a key role in health care policy, serving as chairman of both chambers’ Health committees for about a decade before being named chairman of the Senate Human Services Committee two years ago.

Green grew up in Pittsburgh and went to medical school at Pennsylvania State University. He moved to Hawaii in 2000 with the National Health Service Corp. to serve in rural area hospitals and clinics on the Big Island. He said his intimate interactions with families seeking medical treatment have helped keep him grounded and opened his eyes to the pressing issues facing the state.

“When I’m caring for families in the ER, they share their serious fears and concerns and the hardest parts of life for them. That has always informed what I believed we needed at the Capitol for policy,” said Green (D, Naalehu-Kailua-­Kona) in an interview, citing as examples universal health care for children and drug treatment programs.

“I intend to try to translate Hawaii values into policymaking and governing.”

Espero, 56, has been an advocate for prison and justice reforms in his nearly two decades at the Legislature. He served three years in the House before being elected 15 years ago to the Senate, where he was chairman of the Public Safety Committee before being named chairman of the Senate Housing Committee.

Espero (D, Ewa Beach-Iroquois Point) previously served eight years as executive secretary of the city’s Neighborhood Commission — which oversees the neighborhood board system — under former Mayor Frank Fasi.

He said his 26 years of experience in state and city government would be an asset to the lieutenant governor’s office, where he wants to continue his advocacy and support for affordable housing, prison reform, hemp production and STEM jobs.

“Some of my friends and supporters don’t want me to run because they feel that I’m very effective in the Senate. But if you are planning to run for higher office, obviously there has to be a point where you jump,” he said in an interview.

Espero, whose parents are from the Philippines, was born in Japan and grew up across the globe while his father was in the Navy, having lived in California, Georgia, Virginia, Cuba and Italy. He moved to Hawaii in 1982 after attending Seattle University, where he studied business management.

Green’s Senate term ends next year, so he is not required to resign from the post to run for lieutenant governor. Espero’s term, however, runs through 2020, so he would be required to step down before filing papers to run for another office.