What are the realistic pathways off of fossil fuels and towards a world of abundant clean energy? TED Countdown gathered for its second Dilemma Series -- events designed to look at some of the tricky challenges of climate change, where diverging positions have stalled progress -- to answer this core question of the climate crisis. Through TED Talks and conversations with experts, activists and leading voices in the space, this film delves into the tension between the necessity to extricate ourselves from fossil fuels, which endanger our collective future, and the equally paramount necessity of a stable and secure supply of energy for everyone. (Featuring, in order of appearance: Catherine Abreu, Tessa Khan, Laurence Tubiana, Hisham Mundol, Hongqiao Liu, Rebekah Shirley, Vijaya Ramachandran, Zoë Knight, Mary Robinson, Lindsay Levin, David Biello, Adair Turner, Jérôme Schmitt, Ramez Naam, Tzeporah Berman, Luisa Neubauer, Emily Grubert and Jade Begay)

Canine cognition expert Alexandra Horowitz offers a peek inside the mind of your dog, sharing solutions to common "misbehaviors" that are often simply the result of a pup's attempt to communicate in a world that's very different from their own. Hear about the evolution and psychology behind your dog's actions -- and how to give them a happier, healthier life.

"My very first film was about a town that disappeared," says documentarian John Paget. It was the beginning of a lifelong fascination with cities and towns across the US that experienced slow-motion declines -- but managed to stage a comeback after an era of demise. From the closure of the iconic Route 66 to the roller-coaster history of Buffalo, New York, Paget reveals the power of sharing your town's "civic story" to spark local revitalization.

What if you could transform your anxiety into something you can actually use during your work day? Neuroscientist Wendy Suzuki shares two evidence-based activities -- breathing and movement -- that can soothe your nervous system and fuel creativity and connection.

When the world goes fully electric, what happens to the cars, tools and livelihoods that rely on fossil fuels? Civil engineer and environmental sociologist Emily Grubert visualizes what a clean energy future will look like, outlining the considerations everyone needs to undertake now as the critical, decades-long transition begins.

A self-declared "repair geek," Gay Gordon-Byrne is a driving force behind the right-to-repair movement, which aims to empower people to fix their stuff. She describes how the movement is gaining legislative momentum and breaks down how the global shift away from "throwaway society" can literally turn trash into treasure in a circular economy -- so we can all experience that "Yes! I fixed it!" feeling.

Middle school is a time like no other, as significant biological and emotional changes coincide with profound personal growth, says educator Jerome Hunter. The middle school for boys that he founded centers on a program that helps redefine masculinity through what he calls the three "Cs" -- confidence, communication and community. He shares the growth he's seen when boys are encouraged to explore their own empathy -- and how it could lead to a more just world.

We all experience it: that desire to do something wrong just for the sake of it. Whether it's walking on manicured grass or sticking your finger in a friend's ice cream, psychologist Paul Bloom invites us to see the clever, creative and beautiful side of these minor impulses to do bad. He dives into the psychology behind this all-too-human condition -- and proposes that it helps make our world a little more unpredictable and fun.

Know you should establish clear limits at work but not sure how to do it? Here are a few strategies from relationship therapist and author Nedra Glover Tawwab that can help you feel more empowered and less overwhelmed, both on and off the job.

The emergence of data-driven mass surveillance "is threatening to turn privacy into a relic of the 20th century," says the anonymous YouTube creator known as Ordinary Things. Meanwhile, state-funded troll farms are spreading disinformation and curating chaos on platforms meant to connect us and revolutionize the way we live. Ordinary Things gives an enlightening account of the internet's strengths and weaknesses, warning that the fight for a free internet is a fight for our collective future.

What comes to mind when you think about the most fun moments of your life? Science journalist Catherine Price asked thousands of people across the world this question, and their answers led her to a new definition of "true" fun: a special confluence of playfulness, connection and flow. Hear her thoughts on why having fun is good for your mental and physical health and how to identify the tell-tale signs of "fake" fun -- as well as actionable tips for identifying what brings you joy. (This conversation, hosted by TED science curator David Biello, was part of an exclusive TED Membership event. Visit ted.com/membership to become a TED Member.)

Collaboration in the workplace is more important than ever -- but it's making us less productive in some ways. Here's what collaboration pioneer Rob Cross says is driving us to take on way too much -- and how we can reclaim our time and our peace of mind.

What does an in-flight meal look like when you're traveling to Mars? Designer Phnam Bagley envisions a future where astronauts have nourishing, flavorful food reminiscent of home -- a giant leap from their current staple of "goop-in-a-bag." Learn more about her team's gourmet creations for galactic travel and how these innovations can improve life here on Earth.

Video games naturally tap into the way we learn: they focus our attention and track our progress as we head toward a clear goal. Kris Alexander, a professor of video game design and passionate gamer himself, thinks the same elements should be used in traditional education to cater to different learning styles and engage students across the world, both in-person and online.

Only four percent of construction workers are female -- that's totally unacceptable, but it's also a huge opportunity both for women and for the trades, says youth educator and builder Emily Pilloton-Lam. She makes the case for putting power (and power tools) into the hands of young women and gender-expansive youth, dreaming of inclusive construction sites and daring to ask: What if women built the world they want to see? (Plus, Pilloton-Lam dazzles with a live demo of her own woodworking skills ... while giving the talk.)

Why aren't more people investing in Africa's green energy? Environmental researcher Rebekah Shirley outlines the continent's immense potential for renewable power and calls for collaborative international investment -- and partnership -- in Africa's climate future. "Let's cut past the talk and focus on unleashing the avalanche of a clean energy future that Africa is ready to deliver," says Shirley.

Meet the fantastically colorful and astonishingly adaptable sea slugs that found a way to photosynthesize (or create energy from sunlight) like plants. Diving deep into these often overlooked creatures, invertebrate zoologist Michael Middlebrooks introduces the solar-powered slugs that lost their shells -- but gained the ability to directly harness the power of the sun.

Stuck in an unfulfilling or stagnant job? To achieve a smooth departure without burning bridges, try this three-step exit strategy from career coach Gala Jackson. She'll help you move on to your next position with courage, confidence and clarity.

When programmer Tiffani Ashley Bell learned that thousands of people in Detroit were facing water shutoffs because they couldn't afford to pay their bills, she decided to take action -- in the simplest, most obvious way possible. It's an inspiring story of how one person with tenacity and an idea can create monumental change -- and a demonstration that each of us can find our own way to help the world, even if it means starting without all the answers.

Some days, it's hard to be optimistic. But cynicism -- the idea that people are inherently selfish, greedy and dishonest -- is making humanity lonelier and more divided, says psychologist Jamil Zaki. Presenting fascinating research on cooperation, empathy and trust, Zaki makes the scientific case for optimism and shows us how to break out of the cynicism trap.