Category: Retired

Arnold Schwarzenegger is the former governor of California and one of America's most influential green voices. He's also one of the biggest movie stars in the world and a big fan of the innovators, activists and entrepreneurs featured in the previous 39 episodes of this series. In this final programme, the Terminator star discusses his favourite ideas from the series with Tom Heap and looks forward to the crucial climate change talks in Glasgow in November.

Producer: Alasdair Cross

Tom Heap discovers fresh ways to quantify greenhouse gas emissions with help from satellites, artificial intelligence and former US Vice President Al Gore.

Emissions data from companies and countries can be inaccurate, incomplete or sometimes just plain deceitful. The team at Climate TRACE, led by Al Gore, have devised innovative ways to calculate accurate emissions data from power stations, factories, ships and even planes. That data can be used to reveal unexpected sources of carbon dioxide and methane and to provide independent figures for international negotiations on climate change.

Producer: Alasdair Cross

Researcher: Sarah Goodman

Produced in association with the Royal Geographical Society. Special thanks for this episode to Professor Raphael Heffron from the University of Dundee and Professor Paul Palmer from the University of Edinburgh. Image courtesy of Transition Zero.

Ever thought about the carbon cost of a packet of crisps? At CCM Technologies they think of little else. Their revolutionary fertiliser offers a big step to carbon-free snacking.

Waste from crisp factories or from sewage treatment works can be routed and treated to form the basic building blocks of new fertilisers that can be spread on the ground to grow a new harvest of potatoes- or any other crop we need. The system avoids waste and takes a big cut out of the carbon emissions of traditional fertiliser production. Tom Heap tours the CCM fertiliser plant on the outskirts of Birmingham and discusses the carbon benefits with Dr Tamsin Edwards of King's College London.

Producer: Alasdair Cross

Researcher: Sarah Goodman

Produced in association with the Royal Geographical Society. Special thanks for this episode to Dr Kate Schofield from the University of Plymouth and Dr Abigail González Díaz from the National Institute of Electricity and Clean Energy.

Wind energy is vital in the battle against climate change, but can we make improvements to harness more from them? Tom Heap visits Kelburn windfarm in North Ayrshire to discuss whether 'wakesteering' - reorientating the turbines could see them harness more power collectively. Meanwhile some potential sites are refused or restricted due to the damage caused to wildlife. Hubert Lagrange talks about his childhood obsession with bats which are often killed by the pressure around turbine blades. He's worked to develop a system to sense bat and bird activity and allow the turbines to operate longer through a refined system. Dr Tamsin Edwards discusses how much more potential there is and how much carbon this could save.

Producer: Anne-Marie Bullock Researcher Sarah Goodman

Produced in association with the Royal Geographical Society. Special thanks for this episode to Asst Professor Michael Howland from the Massachusetts Institute of Technology and Professor Nick Jenkins from Cardiff University.