Last night's Oscar ceremony celebrated big wins for actors of color. Kyle Buchanan of the New York Times, and Aisha Harris of NPR's Pop Culture Happy Hour, discuss the diverse honorees.

Brandon Scott is Baltimore’s youngest mayor in more than a century, and promises to reexamine what police reform in one of America’s most dangerous cities looks like.

Frontline doctor, Dr. Yatin Mehta and public health expert, Bhramar Mukherjee discuss the COVID spread in India.

Vivek Maru is founder of Namati, which empowers grassroots groups to protect common lands and enforce environmental laws, while Rhonda Hamilton works with Namati to combat unlawful pollution in her own D.C. neighborhood. They join Hari to discuss their work as part of the ongoing public media initiative Peril and Promise, on the challenges of and solutions to climate change.

Democratic Senator Mazie Hirono of Hawaii is one of the lead sponsors of new legislation to stop anti-Asian hate crimes. In 2012, Hirono became the first Asian American woman elected to the Senate, and is currently the only immigrant serving there. Her new memoir “Heart of Fire” chronicles her own remarkable journey and she joins the show to discuss.

The works of artist Julie Mehretu are informed by global crisis and upheaval. Mehretu is best known for her expansive murals addressing aspects of war, immigration, racism, and other themes that shape our world. Now she is having a mid-career retrospective at the Whitney Museum of American Art, and joins the show from New York.

Even when the federal government has lagged behind, many individual states have forged ahead with climate action. But as Biden’s ambitious pledge places the crisis at the top of the Democrats’ agenda, it’s perhaps hard to imagine that the environment was once a bipartisan issue. Former Ohio Governor John Kasich explains to why the GOP has lost its way.

With climate change on the forefront of many countries, over 40 world leaders pledged to reside carbon emissions by 2030. U.N. Climate Chief Patricia Espinosa joins Christiane to talk about what this means for the future.

Film Director James Cameron joins the show to discuss his latest project. “Secrets of the Whales”, This follows various species in 24 different locations around the world, revealing that these complex ocean creatures might be a lot more like humans than we ever realized.

Youth activists have been at the very forefront of the fight against the climate crisis, and Jerome Foster II has gone from protesting outside the White House to helping implement change in climate policy from inside. At just 18 years old, Foster is now the youngest member of Biden’s White House Environmental Justice Advisory Council.

To discuss the Chauvin conviction as well as the wider geopolitical challenges facing the country, Christiane speaks with Biden’s national security adviser Jake Sullivan in an exclusive interview.

A key question following the conviction of Derek Chauvin is what the verdict might mean for serious police reform in America. Art Acevedo has served as chief of police in Houston and Austin, Texas, and now heads up the Miami Police Department. He joins the show to offer his reaction.

The unfolding of the Derek Chauvin trial is a real demonstration of the power of the people, whose protests and involvement were driven in large part by the Black Lives Matter movement. The movement’s co-founder, Opal Tometi, joins the show to give her reflections.

Harvard professor and classicist Danielle Allen is an expert on how democracy and ethics intersect, and sees important parallels in history, all the way back to Ancient Greece. She speaks with Walter Isaacson about how the Chauvin verdict will impact police reform and our understanding of justice.

After three weeks on hunger strike, jailed Russian opposition leader Alexey Navalny is in solitary confinement in a prison hospital, being treated for what his team calls life-threatening symptoms. European and American leaders are warning of consequences for the Kremlin if Navalny should die. Leonid Volkov is Navalny’s chief of staff and speaks with Christiane from exile in Lithuania.

The U.S. has expelled Russian diplomats and imposed new sanctions on Moscow. The Kremlin, in response, has expelled U.S. diplomats. This latest exchange is part of a U.S. effort to discipline Russia over election interference and its SolarWinds cyber attack. Celeste Wallander served on the National Security Council under President Obama and joins the program to discuss.

In 2017, Larry Krasner became Philadelphia's first progressive DA. His leadership sparked reform movements in prosecutorial offices around the U.S. Now Krasner is up for re-election, and today marks the premiere of a new PBS series about his efforts in office, “Philly DA”, and the release of his new book, “For the People." He joins the show to discuss the ongoing fight for criminal justice reform.

Today’s cyber arms race is a truly global battle and the targets aren’t just nation-states: Each of us is individually vulnerable every time we log into our email, order a rideshare, or swipe our credit card. New York Times journalist Nicole Perlroth says the U.S. is not doing enough to protect its citizens. She joins Hari Sreenivasan to discuss cybersecurity and her new book.

Filmmaker Craig Foster was burnt out and depressed when he took up daily diving at home in Cape Town, South Africa. It was in the ocean that he struck up an unusual friendship with a wild octopus. Filmed over an eight-year period, "My Octopus Teacher" documents this unique bond. The film won a best documentary BAFTA and is nominated for an Oscar.

Both sides have laid out their closing arguments in the trial of Derek Chauvin for the murder of George Floyd. This comes at a moment when policing in America is under intense scrutiny. The New York Times reports that, since day one of the Chauvin trial, there've been more than three police killings per day. To discuss, Christiane speaks with Janeé Harteau, former police chief of Minneapolis.