TEDTalks (video)

In April 2020, epidemiologist-in-training Sophie Rose volunteered to be infected with the virus that causes COVID-19. As a young, healthy adult, she's offering to take part in a human challenge trial, a study where participants are intentionally exposed to SARS-CoV-2 to test vaccines and gather critical data. Explaining how challenge trials could speed up the development of effective vaccines, Rose shares why volunteering was the right decision for her.

On a mission to create a hunger-free world, agricultural entrepreneur Cedric Habiyaremye makes the case for cultivating quinoa -- and other versatile, nutrient-rich grains -- in places experiencing malnutrition, like his native Rwanda. He shares a model to help smallholder farmers across Africa diversify their fields with nutritious and indigenous crops, taking a step towards ensuring healthy foods are available and affordable for all.

An effective COVID-19 vaccine is just the first step in ending the pandemic, says global health strategist Johanna Benesty. In this illuminating talk, she explores the various barriers to "equitable access" -- making sure COVID-19 therapeutics are available to all -- and shares a creative approach to research and development that could ensure vaccines are rolled out fairly, efficiently and at a global scale.

A historic number of Latinx voters participated in the 2020 US presidential election, including a record number of young people casting their ballots for the first time. Civic leader María Teresa Kumar takes a look at the issues closest to youth Latinx voters, including health care, climate equity and racial justice, and considers how this growing demographic could shape American politics for decades to come. Stay tuned for a Q&A with TEDx learning specialist Bianca DeJesus on why the US has a unique opportunity to harness its diversity and define the 21st century.

Activist and author Gloria Steinem is an icon of the global feminist movement. She's spent her life defying stereotypes, breaking social barriers and fighting for equality. In conversation with TEDWomen curator Pat Mitchell, Steinem reflects on the revolutionary roots of the feminist movement, the fundamental need for intersectionality to combat prejudice, and how she overcame her fears with the support of friends. Now she urges future generations of women to advocate for each other in solidarity -- and discover the freedom found in companionship and community.

How do you stand up to authoritarianism? And what does it mean to be "fearless"? In this powerful talk, housewife-turned-politician Sviatlana Tsikhanouskaya describes her unlikely bid to defeat Belarus's long-time autocratic leader in the nation's 2020 presidential election. Painting a vivid picture of how small acts of defiance flourished into massive, peaceful demonstrations, she shares a beautiful meditation on the link between fearlessness and freedom, reminding us that we all have what it takes to stand up to injustice -- we just need to do it together.

In 2014, Erika Cheung made a discovery that would ultimately help bring down her employer, Theranos, as well as its founder, Elizabeth Holmes, who claimed to have invented technology that would transform medicine. The decision to become a whistleblower proved a hard lesson in figuring out how to do what's right in the face of both personal and professional obstacles. With candor and humility, Cheung shares her journey of speaking truth to power -- and offers a framework to encourage others to come forward and act in the service of all.

The clash of ideas is fundamental to creativity and progress, but it can also be deeply destructive and create divisions within companies, communities and families. How do you foster productive debate while protecting against harmful speech and misinformation? Constitutional lawyer Ishan Bhabha lays out structures that organizations can use to navigate ideological disagreement and responsibly bring facts and context to a larger dialogue.

Venom can kill ... or it can cure. In this fascinating talk, marine chemical biologist Mandë Holford shares her research into animal venom, from killer sea snails to platypuses and slow lorises -- and explores its potential to one day treat human diseases like cancer. The mechanism behind this powerful substance is still mysterious, Holford says, but: "Someday, snail venom might just save your life."

For centuries, the Irish funeral wake has served as a time for people to grieve a life lost and celebrate a life lived, together. In this profound and lyrical talk, poet Kevin Toolis laments the fear and denial of death that characterizes increasingly individualistic societies. He reasons that living life fully means embracing our shared mortality -- and offers simple ways to reconnect with your community, the people you love and even yourself.

Our food systems have not been designed to adapt to major disruptions like climate change, says environmental journalist Amanda Little. In this eye-opening talk, she shows how the climate crisis could devastate our food supply -- and introduces us to the farmers, entrepreneurs and engineers who are radically rethinking what we grow and how we eat, combining traditional agriculture with state-of-the-art technology to create a robust, resilient and sustainable food future.

If the 2020 US presidential election is close, the race could drag on in the courts and halls of Congress long after ballots are cast, says lawyer and political commentator Van Jones. Explaining why the customary concession speech is one of the most important safeguards for democracy, Jones exposes shocking legal loopholes that could enable a candidate to grab power even if they lose both the popular vote and the electoral college -- and shares what ordinary citizens can do if there's no peaceful transfer of power.

Viruses mutate and spread from person to person, a dynamic process that often leaves us playing catch-up when there's a new disease outbreak. What if vaccines worked the same way? Virologist Leor Weinberger shares a scientific breakthrough: "hijacker therapy," a type of medical treatment that could attack, modify and spread alongside a virus, potentially treating afflicted individuals and slowing the spread of infections like HIV.

Over his decades-long career as a political activist, Ralph Nader has helped expose some of the greatest misdeeds of large corporations. You may be familiar with the real-world changes his work sparked: the Clean Air Act, automobile safety laws, regulation of the tobacco industry and more. Tracing the arc of his time advocating for change, Nader shares how he helped catalyze social progress against overwhelming odds -- and shows how you can participate in advancing the common good for generations to come.

The racial wealth gap in the United States is shocking: white families have a median wealth nearly 10 times greater than that of Black families. How did we get here, and how can we stop the gap from growing? Wealth equity strategist Kedra Newsom Reeves provides a short history on the origins and perpetuation of racial wealth inequality in the US -- and outlines four ways financial institutions can expand opportunity for Black individuals, families, entrepreneurs and communities.

Companies worldwide are pledging to play a more meaningful role in the well-being of their employees, customers and the environment. How can they turn their promises into action? From creating a representative boardroom to committing to measurable sustainability goals, business leader Dame Vivian Hunt discusses the necessary changes companies can make to embrace stakeholder capitalism -- and shares how it could change business for good.

IKEA currently makes up 0.1 percent of all global carbon emissions -- but by 2030, they're planning to be carbon negative across their business. Discussing new thinking about the lifespan of their products, from the forest to the landfill, Jesper Brodin and Pia Heidenmark Cook of Ingka Group (IKEA) share their company's steps towards sustainably sourcing materials like cotton and wood and redesigning products to extend their use without compromising on quality or affordability. (Narrated by Rosa Howard)

To understand how life works, you need to watch it in action, says bioimaging scientist Gokul Upadhyayula. Taking us down to the cellular level, he shares the work behind cutting-edge microscopes that capture and record, in three dimensions, the complex behaviors of living organisms -- from infecting cancer cells to crawling immune cells -- and what they're revealing about the dynamics of biology. Watch life unfold before your eyes with the incredible visuals in this talk.

The global climate crisis will require us to transform the way we act, says His Holiness Pope Francis. Delivering a visionary TED Talk from Vatican City, the spiritual leader proposes three courses of action to address the world's growing environmental problems and economic inequalities, illustrating how all of us can work together, across faiths and societies, to protect the Earth and promote the dignity of everyone. "The future is built today," he says. "And it is not built in isolation, but rather in community and in harmony."

Under the leadership of Lisa Jackson, Apple's environment and social VP and former head of the EPA, the company is already carbon neutral within their own corporate and retail boundaries. By 2030, Apple hopes to extend carbon neutrality to their supply chain and consumers. In conversation with urbanist and spatial justice activist Liz Ogbu, Jackson shares thoughts on leadership, tech, the environment and building a green economy.

Sophie Howe is the world's only future generations commissioner, a new kind of government official tasked with advocating for the interests of generations to come and holding public institutions accountable for delivering long-term change. She describes some of the people-focused policies she's helped implement in Wales, aimed at cutting carbon emissions, increasing sustainability and promoting well-being as a national goal.

Our descendants own the future, but the decisions and actions we make now will tremendously impact generations to come, says philosopher Roman Krznaric. From a global campaign to grant legal personhood to nature to a groundbreaking lawsuit by a coalition of young activists, Krznaric shares examples of ways we can become good ancestors -- or, as he calls them, "Time Rebels" -- and join a movement redefining lifespans, pursuing intergenerational justice and practicing deep love for the planet.

"We start this new decade knowing that it is the most consequential period in history," says Prince William, The Duke of Cambridge. Inspired by President John F. Kennedy's "Moonshot," he calls on us all to rise to our greatest challenge ever: the "Earthshot." A set of ambitious objectives for the planet, the Earthshot goals seek to protect and restore nature, clean the air, revive oceans, build a waste-free world and fix the climate -- all in the next decade. To do it, we'll need people in all corners of the globe working together with urgency, creativity and the belief that it is possible to repair the Earth.

Climate change is the epic challenge of our lives, and community leaders like Rahwa Ghirmatzion and Zelalem Adefris are already working on sustainable, resilient solutions. Through their organizations in Buffalo and Miami, they're focused on durable, affordable housing for under-resourced communities, the most vulnerable to the instability of climate change. Watch for a lesson on how we can work alongside our neighbors to address climate catastrophe and social inequality. (Narrated by Don Cheadle)

Concrete is all around us: we use it to build our roads, buildings, bridges and much more. Yet over the last 2,000 years, the art of mixing cement and using it to bind concrete hasn't changed very much -- and it remains one of the world's biggest emitters of carbon. Entrepreneur Tom Schuler previews an innovative way to create concrete, potentially turning it into a carbon sink that traps CO2 from the atmosphere -- while producing a viable building material.

"The good news is it's now clearly cheaper to save the planet than to ruin it," says engineer and investor John Doerr. "The bad news is: we are fast running out of time." In this conversation with climate policy expert Hal Harvey, the two sustainability leaders discuss why humanity has to act globally, at speed and at scale, to meet the staggering challenge of decarbonizing the global economy (which has only ever increased emissions throughout history) -- and share helpful examples of promising energy solutions from around the world.

We need to care for and live in harmony with the environment, says climate and gender activist Ernestine Leikeki Sevidzem. The best way to do that? Nurture a forest generation: one that learns to protect nature. Sevidzem shares how she's educating both children and adults in her native Cameroon on what it means to love and preserve the Earth -- and calls for all of us to foster generations that will inherit a mindset that works with nature, not against it.

"Nature reveals itself to us in unique ways, if we stop and look at the world through a window of time," says photographer Stephen Wilkes. Using a special photographic technique that reveals how a scene changes from day to night in a single image, Wilkes exposes the Earth's beautiful complexity and the impacts of climate change -- from the disruption of flamingo migrations in Africa to the threat of melting ice -- with unprecedented force.

With the Climate Reality Project, Al Gore is helping mold future leaders to build the movement for climate survival and social justice from the ground up. He introduces us to four of the Project's graduates, each of whom confronts climate change on their own terms: Ximena Loría, founder of Misión 2 Grados, an NGO influencing public policy in Central America; Nana Firman, "daughter of the rainforest" and advocate for climate justice among Indigenous peoples; Gloria Kasang Bulus, a Nigerian activist for women and education; and Tim Guinee, a first responder and climate change fighter in upstate New York. Together, they're gathering local actors into a global, grassroots movement that aims to turn the climate fight around.

People around the world are demanding clean air -- and cities are starting to respond, says electrification advocate Monica Araya. She takes us on a world tour of urban areas that are working to fully electrify their transportation systems over the next decade, shifting to emission-free motorcycles, cars, buses, ferries and beyond. See what a future without the internal combustion engine could look like -- and what it will take to get there.

The fossil fuel industry knows how to stop global warming, but they're waiting for someone else to pay, says climate science scholar Myles Allen. Instead of a total ban on carbon-emitting fuels, Allen puts forth a bold plan for oil and gas companies to progressively decarbonize themselves and sequester CO2 deep in the earth, with the aim of reaching net-zero emissions by 2050 and creating a carbon dioxide disposal industry that works for everyone.

India has a historic opportunity to power its industrialization with clean energy -- and its energy choices will make or break the world's fight against climate change, says clean energy executive, physicist and author Varun Sivaram. Bringing on-the-ground experience as CTO of India's largest renewable energy company, Sivaram proposes a plan for India to achieve three herculean feats, all at the same time -- and reimagine its economy with renewable energy at its heart.

Yvonne Aki-Sawyerr, mayor of Freetown, Sierra Leone, is on a mission to plant a million trees over the next two years, increasing vegetation in her city by fifty percent while shoring up eroding riverbanks and increasing biodiversity. "This isn't just about planting trees; it's about growing trees, and it's about ensuring that each one of us is part of the process," she says. "A million trees is our city's small contribution to increasing the much-needed global carbon sink."

In 2019, Amazon signed the Climate Pledge, a commitment to become a net-zero carbon business by 2040. Dave Clark, Amazon's chief of consumer retail, and Kara Hurst, head of the company's sustainability efforts, sit down with entrepreneur and activist Lindsay Levin to discuss how the company is planning to reduce its carbon footprint across all aspects of business -- while inviting other companies to join them in this transformation.

"Business is screwed if we don't fix climate change," says economist Rebecca Henderson. In this bold talk, she describes how unchecked capitalism destabilizes the environment and harms human health -- and makes the case for companies to step up and help fix the climate crisis they're causing. Hear what a reimagined capitalism, in which companies pay for the climate damage they cause, could look like.

With the ambitious goal of becoming the first carbon-neutral continent by 2050, the European Union has committed to creating a greener world for future generations. In this bold talk, Ursula von der Leyen, President of the European Commission, details the challenges and opportunities that come with transitioning an entire continent to clean energy -- and shows why fixing climate change calls for everyone to take action.

"History has shown us that in moments of crisis, society can truly transform," says environmental educator Severn Cullis-Suzuki. Nearly 30 years ago, at just 12 years old, she spoke at the UN's Earth Summit in hopes of reversing the planet's slide into ecological disaster. Some at the summit listened and took radical action, but for the rest of the world, it was business, politics and full-steam-ahead economic growth. Now, Cullis-Suzuki shares another warning about the future, this time informed by the COVID-19 crisis -- and urges us all to make our actions on climate change reflect our words.

"This decade is a moment of choice unlike any we have ever lived," says Christiana Figueres, the architect of the historic 2015 Paris Agreement. The daughter of Costa Rica's beloved President José Figueres Ferrer, she shares how her father's unwillingness to lose the country he loved taught her how stubborn optimism can catalyze action and change. With an unshakeable determination to fight for the generations that will come after us, Figueres describes what stubborn optimism is (and isn't) -- and urges everyone to envision and work for the future they want for humanity.

Why has there been so little mention of saving Black lives from the climate emergency? For too long, racial justice efforts have been distinguished from climate justice work, says David Lammy, Member of Parliament for Tottenham, England. In a stirring talk about building a new movement to care for the planet, Lammy calls for inclusion and support of Black and minority leadership on climate issues and a global recognition that we can't solve climate change without racial, social and intergenerational justice.

"If we don't act now on climate change, this coming century may be one of humanity's last," says António Guterres, Secretary-General of the United Nations. As the world recovers from the COVID-19 pandemic, Guterres urges us to use this moment to rebuild with ambitious climate action in mind -- and lays out a blueprint for getting companies, governments and countries to reach net-zero carbon emissions by 2050. "We can only win the race to zero together," he says. "I urge you all to get on board."

"For the first time, we are forced to consider the real risk of destabilizing the entire planet," says climate impact scholar Johan Rockström. In a talk backed by vivid animations of the climate crisis, he shows how nine out of the 15 big biophysical systems that regulate the climate -- from the permafrost of Siberia to the great forests of the North to the Amazon rainforest -- are at risk of reaching tipping points, which could make Earth uninhabitable for humanity. Hear his plan for putting the planet back on the path of sustainability over the next 10 years -- and protecting the future of our children.

Civil rights leader and longtime US congressman John Lewis spent his life fighting for freedom and justice for everyone. In this illuminating conversation with lawyer and activist Bryan Stevenson, Lewis discusses the essential importance of voting, shares encouraging words of wisdom for the generation of young people currently organizing in the struggle for racial justice and tells moving stories from his decades of making "good trouble" -- at the Freedom Rides, March on Washington and in the halls of Congress. "When you see something that's not right or fair or just, you have to say something," Lewis says. "You have to do something." (This conversation is part of the TED Legacy Project. Recorded November 19, 2019)