“We take care of the females if they are small.”

Climate change poses a great visual challenge to filmmakers. How do you convey the imperceptible, an invisible gas that is slowly warming the planet and causing incremental yet monumental change? Its worst consequences haven’t yet happened, and many of the changes are subtle differences, not dramatic ones. Even the best visual examples – hurricanes, flooding and forest fires – are events that already happen, just with greater intensity than they once did.

Filmmakers also must convey technical information visually, without losing narrative momentum, which means relying on text within the film, explanatory voiceover and often, supplementary written material. And they must also grapple with a dark theme without overwhelming viewers: An end to everything that we now know as familiar.

We have one advantage as filmmakers interested in climate change, because it is happening, now. It is the ultimate in present-tense storytelling, the secret sauce that we’re looking for in narrative nonfiction. Impactful films about climate change tend to use present-tense storytelling to their advantage. The best fall into several categories:

• Loveletters to a place or a disappearing ecosystem, like Jeff Orlowski’s Chasing Coral* or the visual masterpiece of this genre, Werner Herzog’s Encounters at the End of the World. *(A note: Randy Olson in Don’t Be Such a Scientist says the storytelling in the HBO Real Sports episode about coral reefs is much stronger. I’ll report back.) 
• Reflexive pieces that use the filmmaker’s experience to inform viewers, such as Josh Fox’s  documentary about his family’s experience with fracking, Gasland.
• Explanatory, journalism-based pieces that use interviews, experts and voiceover to convey technical information or explore a problem, sometimes by asking a provocative question. Jordan Brown and Derrick Jensen’s Forget Shorter Showers excels at this, in part because it started as an essay that dealt with the provocative question of whether individual action can make a difference.
• And my favorite category, the films that use narrative nonfiction techniques and cinema verite to put viewers in a place they might not otherwise go, following the story of someone who is living with the changes wrought by the imperceptible. Plastic China by Jiu-Liang Wang is among them, as is Dulce, the film I’ll discuss below. (It’s noteworthy that both of these films use children as central characters, which allows us to understand who will be most affected by what is to come.)

Dulce, a 10-minute film by Guille Isa and Angello Faccini, is featured on New York Times Op-Docs. The film is in Spanish, with English subtitles – although dialogue is limited. It opens with sound leading the picture: splashing water and the whining tones of a young, distraught girl. We see Dulce, 8, learning to swim with her mother and a man from their village on the Pacific Coast of Colombia. The girl’s mother, Betty Arboleda, swims closer to the camera, with her daughter clinging to her back.

“If you hold onto me, you won’t learn to swim,” she tells her daughter in Spanish.

Within the first 30 seconds, we have been given a storytelling cue. Dulce, we understand, is a sweet, coming-of-age tale. It has an unanswered question: Will Dulce learn to swim? But the stakes could not be higher. She doesn’t need to learn to swim to play in the pool with her friends. Dulce needs to know how to swim to survive climate change. The filmmakers use a moment of time in a child’s life to illustrate a larger theme. This is not just a story about climate change, it is a story about how we go on as a species, how we will still have these coming-of-age moments, even as we live with what is happening to our planet.

The filmmakers use dialogue here to illustrate the menace. “This month the sea gets angry,” Betty warns her daughter. “And when it gets angry the boat always overturns.”

Notice the two gorgeous shots of Betty, which run from 50 seconds to 1:24. She is centered in them, in medium closeups. First in the water, trying to explain to her daughter why she must swim, and then we see her in profile in a more introspective moment, on a small canoe as it approaches the mangrove swamps where she works as a pianguera harvesting black clams by hand.

In the next scene, beginning at 1:30, we are in the muck with Betty, as she engages in the dirty and difficult work of a pianguera. There are excellent examples of matched action sequencing here. Tight shots of her gloved hand picking up a clam and then a cut to her other hand holding a smoking smudge stick of coconut fiber to keep insects at bay. There are medium shots of her feet in rubber boots, walking through the mangroves. Wide shots of her in the overall setting. Without words, we understand that this is difficult physical work.

The scene relies on the beauty of natural sound, no dialogue or music. We hear insects and bird life, the sucking sound as Betty’s boots pull away from mud, and the splash of her rinsing the clams she gathers in the brackish water of the mangrove swamp.

I wanted to deconstruct the storytelling arc and parallel editing techniques to better understand how an intimate story could be used to explore a wider theme. The film opens with Betty and her daughter together. We see Betty at work as a pianguera, and then at home, with a wide shot showing the home on stilts. The sequence cuts to Betty framed within a doorway with another daughter, hanging laundry. (See 2:40 to 2:50) Then, we go to a sequence with Dulce and other children sitting on a dock, with some splashing and playing. This scene uses dialogue to cast light on Dulce’s learning-to-swim dilemma. We eavesdrop on her conversations with her friends. The camera is close, using a shallow depth of field to focus on Dulce. Again, natural sound is at work.

At 3:44 minutes, we cut back to Betty’s daily work gathering clams. And at 4:30, we are back to Dulce. The scene opens with her centered in the frame on the dock, her back to us. Around her, other children jump into the water and swim. We come around to a close shot of Dulce’s face and her clear indecision about joining her fellow swimmers. By centering her in the frame, the filmmakers have echoed the early scenes of her mother. It reminds us of the question at the heart of this story: Will Dulce learn to swim and will she grow up to be as strong as her mother?

The passage of time is conveyed beautifully with wide shots of the tide coming in closer to the family’s house on stilts. We see now that waters are higher than when Betty was hanging laundry to dry.

At 5:08, mother and daughter reunite. Betty is combing Dulce’s hair. This is a tender moment and dialogue advances the emotional arc of the story. “Are you mad at me?” Dulce asks. “No. Whether you can swim or not, you’re my daughter,” her mother tells her. Then, though, she lays on the guilt. “When children don’t swim, their mothers get sad.”

Next, we see them swimming together. Dulce, reluctantly, but with her mother’s encouragement. The following scene is also together: Dulce goes clam-gathering with her mother. At 7:50, note the use of negative action in a wide shot of the clam gatherers walking away from the camera into the Mangroves, and the visual beauty of the smudge smoke. We cut to Dulce helping her mother. Of the eight clams she has gathered, she can keep only one, her mother tells her, while she and the other women linger on a break. “It’s the male. We take care of the females if they are small. We put them back.”

Next, at 9:20, there’s a wide shot of Dulce and her mother walking along the horizon, in silhouette at the edge of the mangroves. There’s a voiceover of Dulce’s version of events. “I go to the roots, to the mangroves looking for clams, and find but trash among the roots. Leave the small shells where they be, that they may grow and we may help them.”

The film closes with natural sound from the mangrove swamp and text, explaining how communities in Colombia’s Iscuande region are working to preserve the mangrove forests to provide a buffer against rising seas and to absorb the carbon that contributes to climate change.

No matter how visually stunning, how intimate the coming-of-age narrative, words are still necessary to explain the imperceptible.