There's plenty of urgency firing up Prime Production's "Two Degrees," now playing in the Guthrie Theater's Dowling Studio. It opens with a scene of passionate lovemaking and closes with a call to change the world. In between these two points it embodies our current national debate about moral certainty and political expediency through one woman's intensely personal story.

That woman is a paleoclimatologist played by Norah Long. Emma's ice core research in Greenland has convinced her that the planet is nearing the tipping point in terms of global temperature. She's come to Washington, D.C., at the behest of Louise (Jennifer Whitlock), a senator and longtime friend, to testify about climate change. To complicate matters, she's sleeping with a man who lobbies on behalf of mineral mining companies while she's simultaneously haunted by guilt, regret and the ghost of her recently deceased husband.

"Two Degrees" jumps back and forth in time as these and various other plot lines play out. There's the relationship between Emma and Louise, complicated by a revelation about their shared past. There's the amiable Greenlander who'd be happy to keep Emma warm during long arctic nights. There's the cynical world of D.C. politics, where Emma's ideals meet partisan realities. And there's the global disaster looming over the play, much like set designer Annie Henly's sculpted glacier-like backdrop.

This production offers much to like. Long capably embodies a woman driven by both rigorous logic and raw, almost palpable, grief. She's confident in her own discipline and unable to compromise either politically or personally. She's ably complemented by Joel Liestman, who alternately portrays her dead husband Jeffrey, a Senate aide, and, in an odd plot divergence, the amorous Greenlander.

Toussaint Morrison is engaging as the lobbyist who'd like his casual hookup with Emma to evolve into something more. Whitlock is less comfortable in her role as Emma's senator friend, occasionally wobbling as she seeks the correct tone.

The real challenge for director Shelli Place and her cast, however, is the unwieldiness of playwright Tira Palmquist's script. Any one of its various threads offers a promising direction. Weave them all together and "Two Degrees" starts to sag, whiplashed by too many plot twists over the course of 90 minutes.

Despite these weaknesses, this production offers a promising opening for the second season of Prime Productions. This new Twin Cities' theatrical venture focuses on the wholly commendable mission of elevating the often invisible presence of women artists over 50. "Two Degrees" fulfills that mission in fine fashion.

Lisa Brock is a Twin Cities theater critic.