Brian Schatz and Barack Obama

White House / Pete SouzaBrian Schatz gets a nod from POTUS.

There is no surplus of environmental leaders in Congress right now, especially with the impending retirements of Reps. Henry Waxman (D-Calif.) and Rush Holt (D-N.J.). So it may alarm enviros to learn that the greenest new senator, Brian Schatz (D-Hawaii), is facing a primary challenge. And in an especially strange twist of fate, the amiable young liberal — in a solidly Democratic state — is being primaried from his right. Craziest of all is the fact that he could lose.

Luckily for Schatz, though, he just got a boost from Hawaii’s most famous son, President Barack Obama.

Here’s the backstory: Schatz’s seat was held for over four decades by Daniel Inouye (D). When Inouye passed away in December 2012, Gov. Neil Abercrombie (D) got to appoint a replacement. Inouye requested that he be succeeded by Rep. Colleen Hanabusa (D). Abercrombie — a longtime rival of Inouye’s — instead appointed Schatz, his lieutenant governor. Now Hanabusa is running against Schatz for the Democratic nomination in this year’s election, and a February poll showed them in a dead heat.

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In just over a year in the Senate, Schatz has quickly emerged as a leader on climate change and sustainability. Earlier this month, he organized the Senate’s all-night talkathon about climate change. He told Grist it was just the beginning of the work that he and his colleagues will do to raise awareness about the issue. He’s also working on a bill that would require major polluters like oil companies to pay a fee for each ton of carbon they emit. And he has sponsored a raft of small-bore bills to incentivize energy efficiency and green technology.

As an archipelago in the middle of the Pacific Ocean, Hawaii faces especially dire threats from climate change. Experts say climate change is already causing problems for the state’s unique native plant and animal species and its coral reefs. Climate change could also lead to more severe extreme weather events in Hawaii such as tropical cyclones.

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And as a state that’s heavily dependent on tourism, environmental preservation in general is essential to Hawaii’s economy. Schatz knows this well and has sponsored a bill to study the creation of more national parks in Hawaii. He is also cosponsoring a “complete streets” bill that would encourage sidewalks and bike lanes on federally funded roads. As a member of the Senate Committee on Energy and Natural Resources and chair of the Subcommittee on Water and Power, he’s in a good position to do more to protect the state’s natural beauty and resources.

Hanabusa is by no means anti-environment. The League of Conservation Voters has previously endorsed her as a candidate for Congress and her voting record has earned an impressive 95 percent LCV lifetime rating. But she belongs to the centrist, pro-business New Democrat Coalition.

While environmentalists might well cheer Obama’s endorsement because it could help Schatz win, they should not be so naive as to think it means anything about Obama’s commitment to combating climate change. A president supports his party’s Senate incumbent in all but the most extraordinary circumstances. On top of that, Schatz is the president’s ally. (He endorsed Obama in the state’s 2008 Democratic presidential primary, while Hanabusa supported Clinton.)

There is nothing for greenies to fear from Hanabusa, but there would be a lot for them to miss in Schatz’s absence.