"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.

Known for big, attention-grabbing installations -- like his four towering waterfalls in New York's East River -- Olafur Eliasson has scaled down his latest project, Earth Speakr: an art platform for kids designed to spur budding climate activists to lead discussions on nature, conservation, pollution and more.

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."

A brief answer to one of the key questions about climate change: What is net zero? (Written by Myles Allen, David Biello and George Zaidan)

A brief answer to one of the key questions about climate change: Why is the world warming up? (Written by Myles Allen, David Biello and George Zaidan)

Cities pump out 70 percent of all global carbon emissions -- which means they also have the greatest opportunity to lower CO2 levels and energy consumption. Climate and data scientist Angel Hsu shares how cities around the world are leading the response to climate change by innovating new, low-carbon ways of living.