Director of the National Institute of Health Dr. Francis Collins, who has guided the U.S. through the COVID-19 crisis, recently announced he will step down after 12 years and three presidents. He tells Walter Isaacson how vaccine resistance and conspiracy theories presented one of his most difficult challenges as director.

A U.S.-led alliance at the COP26 summit has pledged to cut methane emissions by 30% by the end of the decade. The pledge is non-binding, but it is being touted as an early win for this climate summit and for its host -- British Prime Minister Boris Johnson. He sat down with Christiane for an exclusive interview from the summit.

The urgency at this year's COP26 summit is palpable, and few are more aware of this than former Secretary of State and President Biden's climate tsar John Kerry. Kerry sits with Christiane to discuss efforts to lower carbon emissions in India and China.

At the COP26 summit today, there was a passionate plea from Barbadian Prime Minister Mia Mottley. Her tiny nation is among those bearing the brunt of climate change. She’s calling on rich nations and major polluters to step up and help nations like hers. Mottley joined Christiane for a frank discussion in Glasgow after she addressed the plenary of national leaders.

Scotland's First Minister, Nicola Sturgeon, finds herself hosting top officials and climate leaders from all corners of the globe as they descend on her country. There will no doubt be a lot of talk. Will it translate into action? The Scottish leader joins Christiane to explain why she feels cautiously hopeful.

Global leaders are gathered at the COP26 summit in Glasgow this week to collaborate in the fight against climate change. Among them is European Union Commission President Ursula von der Leyen, who says the success of the conference hinges on the creation of concrete proposals that will limit global warming to 1.5 degrees Celsius.

Last Thursday's House Oversight Committee hearing featured testimony from six major fossil fuel companies and trade associations about their part in climate change, and whether they misled the public about the reality of the crisis. Rep. Ro Khanna helped lead this historic hearing. He joins Hari Sreenivasan to explain the disconnect between what these companies say and what they do.

As the pandemic eases in some parts of the world, we’re seeing the so-called “great resignation:” 20 million people in the U.S. have quit their jobs since April, according to federal statistics. Jennifer Moss explains this phenomenon in her new book "The Burnout Epidemic," and speaks with Michel Martin about why this is a cultural, rather than an individual, problem.

President Biden and the U.N. Security Council are calling for Sudan's civilian government to be restored, while both the State Department and the World Bank have suspended aid to the country. For more on this, Bianna speaks with Mohanad Hashim, a freelance Sudanese journalist who has just returned to London.

President Biden is back in the global spotlight, meeting with G20 leaders -- and Pope Francis in Rome -- prior to the U.N. climate summit in Glasgow next week. What is the current state of the president’s domestic agenda -- and how could it impact American diplomacy? Experts Mo Elleithee and Mark Landler join the program to offer their analysis.

Today, President Biden met with the Pope at the Vatican – his fourth face-to-face meeting with Pope Francis. The 90-minute discussion covered a wide range of issues, including climate and inequality. One who understands the significance of the meeting is Cardinal Blase Cupich, the Archbishop of Chicago.

The supply chain crisis is crippling the mercantile business in the U.S., with overflowing ports, trucks queuing for miles, empty shelves, and rising prices – all this as the holiday season inches closer. David J. Lynch is a correspondent for The Washington Post and joins the show to discuss where it all went wrong and whether it is fair to lay the blame at President Biden’s feet.

Today President Biden heads to Rome for the G20, a pit stop on the way to the COP26 summit in Glasgow, where the world must hammer out a climate plan to avoid catastrophe. Adding to the pressure onBiden, Democrats are at a pivotal stage in the passage of their infrastructure bill worth trillions of dollars. To break down the latest, Bianna speaks with reporter Lauren Fox.

In her latest piece for The Atlantic, journalist Kim Ghattas focuses on three states that once offered real hope for democracy, only to be dashed: Hong Kong, Afghanistan, and Ghattas’ home country of Lebanon. Ghattas joins the show from Beirut.

As President Biden departs the U.S., Congress is grilling the fossil fuel giants. The CEOs of Exxon, BP, Shell, and Chevron testified today virtually about whether they knew their products were fueling climate change. For more on this is Mark Hertsgaard, a journalist and executive director of the news consortium Covering Climate Now.

Facebook CEO Mark Zuckerberg today outlines a new vision for the embattled company, but experts are warning Facebook hasn’t done enough to address its problems. The company is in hot water after a whistleblower released internal documents and testified that the platform is choosing profit at any cost. Adam Conner previously headed up Facebook’s privacy and public policy team.

Greg Zuckerman is an investigative reporter with The Wall Street Journal. In his new book, he takes us behind the scenes of the years of groundbreaking research that paved the way for the mRNA vaccines we have today. Zuckerman speaks with Walter Isaacson about the unsung scientific heroes who created them.

Oscar-nominated director Ava DuVernay's latest project is "Colin in Black and White," a Netflix series that tells the story of NFL player Colin Kaepernick's high school years. DuVernay joins Christiane to discuss this unique collaboration and what it's like to be trusted with someone's story.

In May, author Michael Lewis joined Christiane to discuss his book "The Premonition." Less than three weeks later, tragedy struck Lewis and his wife Tabitha Soren: Their 19 year old daughter Dixie was killed in a car crash, along with her boyfriend. Lewis is only lately ready to talk about it publicly. He joins Christiane to reflect on his loss.

People in many countries are finding their way back to pre-COVID-19 life. Navigating all this may become a lot easier with the release of psychologist Doreen Dodgen-Magee’s new book, "Restart: Designing a Healthy Post-Pandemic Life." She lays out how we can create better relationships with ourselves, our loved ones, and our tech – as she explains to Hari Sreenivasan.