Do memes hold the key to the White House? Supporters of Kamala Harris hope so. Already online communities have sprung up to boost her campaign and they’re chopping up her speeches and appearances to flood the internet with viral clips. Their aim is to swing the youth vote in Harris’ favour and get other disengaged voters to turn out on election day. Will it work?

Complex ocean currents keep Europe warm and bring rain to Africa, but could they come to an end?

The Atlantic Meridional Overturning Circulation (AMOC) is a system of ocean currents within the Atlantic Ocean, transporting warm water north towards the Arctic and returning cold water south towards Antarctica. The Gulf Stream is a component of AMOC, which carries warm water from the Gulf of Mexico, up along the eastern coastline of the United States.

AMOC’s currents are driven by changes in water density due to changes in ocean salinity and temperature. Increasing ocean temperatures and freshwater flows from melting ice sheets due to climate change, have the potential to weaken AMOC. This could lead to cooler temperatures in Europe and a drop in rainfall in key agricultural areas in places like Africa and Asia, in turn affecting millions of people.

Host Claire Graham talks to the BBC’s Climate Editor Justin Rowlatt. Produced by Cathy Young for the BBC World Service.

The Media Show hears from journalists who were witness to the attempted assassination of Donald Trump. Gary O'Donoghue was reporting live on the BBC World Service when the shots were fired, and Hadriana Lowenkron was at the rally for Bloomberg. Anna Moneymaker, a photographer for Getty Images, describes how she managed to capture what has become a defining image of the event.

Some in the US have since accused the media of fostering a hostile environment for politicians, and Ros and Katie discuss the nature of political discourse with Jay Caspian Kang of The New Yorker and Megan McArdle, a columnist at The Washington Post.

Brokering peace between warring nations, how does it work and what causes failure? We look at Qatar’s role in the Middle East and at insight gained from the Northern Ireland peace process. Host Claire Graham talks to Lyse Doucet – the BBC’s Chief International Correspondent about how the state actors in peace mediation have changed and adapted over time. Plus Lyse tackles the question - can you really be a mediator if you are not neutral? Produced by Cathy Young for the BBC World Service.

Oz Katerji was reporting from outside the children’s hospital in Kyiv that was hit after Russia launched a wave of missiles on Ukraine earlier this week. He explains how he reached the decision to stop being a journalist and - for a few hours – join the rescue effort.

In the aftermath of his halting debate performance, the editorial boards of some major US newspapers have called on Joe Biden to withdraw from the presidential race. We ask why this issue is only being discussed widely now, and talk to Annie Linskey, White House reporter, The Wall Street Journal, who raised a comprehensive set of concerns about Biden’s health but faced a backlash from others in the media. We also speak to Nayeema Raza, co-host, Semafor’s Mixed Signals podcast and Jill Abramson, former executive editor, The New York Times

Also on the show, we hear from El Hunt, commissioning editor for The Evening Standard, about what it is like reporting from the Glastonbury Festival and hear Ros Atkin's remix of the BBC News' theme tune in his debut DJ set at Glastonbury and how Louis Tomlinson of One Direction bought football home to Worthy Farm.

John Simpson, in discussion with the BBC's unparalleled range of experts across the world, examines the key issues for voters in the UK’s imminent general election, explores the plight of women in Afghanistan after almost three years under Taliban rule and looks at the impact of the extreme heat affecting parts of the world this summer.

In the week that Julian Assange walks free, we explore the story of WikiLeaks' unprecedented data releases and how he and his organisation changed the way journalists and newsrooms operate. We also assess if his guilty plea to a US espionage charge will have a chilling effect on national security journalism. Also in the programme, Steven Moffat, the writer behind global TV hits such as Sherlock and Doctor Who. He reveals why he wanted to tackle cancel culture in his new comedy-drama “Douglas is Cancelled”.

John Simpson, in discussion with the BBC's unparalleled range of experts across the world, examines whether Ukraine is now preparing for a deal, assesses what’s at stake as Nato members prepare for their annual summit in Washington next month, and asks who owns the moon as we enter a new era of lunar exploration.

In the space of 20 years, podcasting has gone from hobby to big business. What’s the secret of success for the best in the industry? Also on the show, why there’s trouble at the top of The Washington Post, and new research that shows more and more people are avoiding the news.