Some traders are betting on the UK crashing out of the EU without a divorce agreement. Should we be concerned that they wield too much political influence?

Both the British Prime Minister's sister Rachel Johnson, and the former Conservative finance minister Philip Hammond, have publicly voiced concerns in recent day that Boris Johnson is backed by financiers speculating on a sharp fall in the pound following a possible no-deal Brexit on 31 October.

Manuela Saragosa asks how credible are such claims? How are the markets positioned for Brexit? And is there any way of even knowing who is "shorting" the pound, ready to profit from an unexpected fall in its value?

The programme includes interviews with David Riley, chief investment strategist at Bluebay Asset Management, and with Jane Foley, head of currency strategy at Rabobank. Plus the BBC's Edwin Lane learns how to play the foreign exchange markets from Piers Curran of Amplify Trading.

Producer: Laurence Knight

(Picture: A woman looks at a chart showing the drop in the pound against the dollar after the UK vote to leave the EU in 2016; Credit: Daniel Sorabji/AFP/Getty Images)

How WeWork's Adam Neumann lost his job after a disastrous attempt to list the company on the stock market. Manuela Saragosa speaks to the Wall Street Journal's Eliot Brown about the charisma of Adam Neumann and how it helped raise billions from investors, and to Andre Spicer from the Cass Business School about the cult of the founder-CEO. Scott Galloway, professor of marketing at the New York University Stern School of Business, explains why WeWork's IPO failure should be a lesson to the markets.

(Photo: Adam Neumann, Credit: Getty Images)

Ed Butler speaks to Professor Tom Crowther from the Swiss university ETH Zurich, who says planting billions of trees around the world is by far the biggest and cheapest way to tackle climate change. Marcelo Guimaraes, chairman of Mahogany Roraima, a commercial timber and reforestation plantation in the northern Amazon rainforest, discusses how that would work in practice.

(Photo: A tree in a deforested area of the Amazon rainforest, Credit: Getty Images)

What is our ethical duty to eliminate carbon emissions? Was Swedish teen activist Greta Thunberg right to express such anger at the UN Climate Action Summit in New York this week?

Justin Rowlatt asks leading moral philosopher Peter Singer, professor of bioethics at Princeton University, whether someone driving a petrol- fuelled car can really be held responsible for increasing the risk of drought in Africa. And why should we give up taking long-haul flights, if the tiny amount of carbon emissions that saves will make practically no difference in the grand scheme of things?

Plus climatologist Emily Shuckburgh explains why she is not despondent about climate change - despite seeing the effects first-hand on polar research trips - and how a new institute she is heading at Cambridge University is generating a lot of excitement among academics.

Producer: Laurence Knight

(Picture: Dead cow in drought-struck Kenya; Credit: muendo/Getty Images)

Just how bad will it get if the world fails to get to grips with climate change?

On day two of the UN Climate Action Summit in New York, Justin Rowlatt speaks to David Wallace-Wells, author of the apocalyptic book Uninhabitable Earth, which lays out the dire predictions of climatologists for the coming decades if humanity continues to put ever more carbon dioxide into the atmosphere unabated.

Yet despite the potentially terrifying outlook, it remains very difficult to motivate politicians and the public to take meaningful action to cut emissions. Why is that, and how might that change? Kelly Fielding is a social psychologist at the University of Queensland in Australia, and has some of the answers.

Producer: Laurence Knight

(Picture: Dead bumblebee from the cover of Uninhabitable Earth by David Wallace-Wells; Credit: FXseydlbast/Getty Images)

The Swedish teenage activist Greta Thunberg explains how she aims to get the world's governments gathered for the UN Climate Action Summit in New York to take meaningful action on global warming.

Justin Rowlatt speaks to her about her ambitions for her transatlantic trip, and whether one person can really make that much of a difference.

In order for her mission to succeed, it will mean rebuilding the global economy from the ground up, including the phasing out of most of the oil and gas industry. John Hofmeister, the former president of Shell's US subsidiary, claims the big oil companies are ready and willing to do their part, if the politicians will only give them the green light.

Producer: Laurence Knight

(Picture: Greta Thunberg testifies at the US Congress in Washington DC; Credit: Alex Wong/Getty Images)

What next for the social media giant? Jane Wakefield speaks to one former mentor of Mark Zuckerberg, and a British member of parliament about what changes Facebook needs to make after data scandals and concerns over its power.

(Photo: Facebook logo, Credit: Getty Images)

What robots driving cars can tell us about artificial intelligence. Ed Butler speaks to Bryn Balcombe, chief strategy officer of the autonomous vehicle project Roborace. Gary Marcus, professor of psychology at New York University, explains why he thinks AI development is fundamentally limited. Yoshua Bengio, professor of computer science at the University of Montreal in Canada, gives a defence.

Producer: Laurence Knight

(Photo: A Roborace robot-driven car in action on the track, Credit: Getty Images)

How economies spring up in extreme places from refugee camps to prisons. Ed Butler speaks to economist Richard Davies, author of a new book called Extreme Economies, who describes the economic activity in extreme places, from a Syrian refugee camp in Jordan to one of the toughest prisons in the world, in the United States. Former US prisoner Lester Young fill us in on how to trade behind bars.

(Photo: A prison in Louisiana State Penitentiary, Credit: Getty Images)

Should shareholders come first? Or should companies also serve their employees, customers, and society in general?

Ed Butler explores the growing backlash against "shareholder primacy" - the idea espoused in the 1970s by economist Milton Friedman that businesses should only care about maximising the bottom line for the benefit of their investors, and that other stakeholders' interests should not be their prerogative.

He speaks to Lenore Palladino, economics professor at the University of Massachusetts Amherst, who has a list of changes she wants to see in the way that American companies are governed, plus Ken Bertsch of the Council of Institutional Investors, who says that the real problem is not the role of investors like the ones he represents, but too much focus on short-termism.

Meanwhile Chris Turner thinks he has the solution - he works for the non-profit organisation B Lab, which provides an objective assessment to hundreds of corporations of whether they are having a positive impact on society.

(Picture: An American flag is displayed on a trading screen at the New York Stock Exchange; Credit: Bryan R. Smith/AFP/Getty Images)

Will the roll out of online lending stimulate economic boom or just a credit binge in Africa?

Ed Butler speaks to many of the businesspeople providing the continent with much needed banking services via mobile phones. They are optimistic that financial inclusion for small businesses, farmers and rural consumers could stimulate much faster economic growth. But is there a dark side to the sudden availability of east loans?

The programme includes interviews with Matthew Davie, chief strategy officer at the US micro-lending fin-tech Kiva; Omotade Odunowo, chief executive of the Nigerian digital wallet service Fets; Joshua Oigara, chief executive of Kenya's biggest commercial bank KCB; and Kevin Njiraini, regional director for southern Africa and Nigeria at the International Finance Corporation.

(Picture: Young African woman using a mobile phone; Credit: wilpunt/Getty Images)

Why it's time to start paying attention to the global remittances industry. Ed Butler speaks to Monica, a nurse from the Philippines working in the UK - one of millions of people around the world who regularly send money back to their families abroad. Dilip Ratha from the World Bank describes the scale of the money flows, and the persistently high costs of international money transfers. Ralph Chami from the IMF highlights the challenges such big inflows of cash can have on developing countries. And Elena Novokreshchenova from the company Remitly explains how technology can help reduce costs.

(Photo: A bank teller counts bills in Manila, Philippines, Credit: Getty Images)