In the final episode of the year, Anna speaks to Professor Tim Lenton (Chair in Climate Change and Earth System Science at the University of Exeter) about climate tipping points – the thresholds where a tiny change could lead to large and often irreversible transformations in the Earth system, with potentially disastrous consequences. Examples of such 'negative' tipping points include the dieback of the Amazon rainforest, the melting of the Greenland icesheet, and the collapse of the Atlantic Meridional Overturning Circulation (AMOC). But not all tipping points are bad. In the interview, Anna and Tim also discuss how the triggering of 'positive tipping points' within human societies could lead to rapid decarbonization.

For further reading, please see:

• Tim Lenton's book 'Positive Tipping Points: How to Fix the Climate Crisis'.
• Tim Lenton's article 'Why some tipping points may be positive for the planet' in Chatham House's magazine 'The World Today'.

COP30 in Belém is over. What happened at the conference? What were the main outcomes? And what needs to happen next?

To find out, Anna speaks to Jennifer Morgan (Senior Fellow at the Fletcher School of Law and Diplomacy at Tufts University; Fellow at the Hertie School of Governance; and former State Secretary and Special Envoy for International Climate Action at the German Federal Foreign Office) and David Waskow (Director for the International Climate Initiative at the World Resources Institute).

COP30 is about to begin. Where do we stand ahead of the conference? What are the key issues to watch, and how might the complex geopolitical context influence the discussions in Belém?

To find out, Anna is joined by three Chatham House colleagues: Ana Yang (Director of the Environment and Society Centre), Bernice Lee (Distinguished Fellow and Senior Advisor) and Nick Bridge (Associate Fellow at Chatham House and former UK Special Representative for Climate change).

For additional analysis, please see:

• The expert comment 'What can COP30 achieve, following US withdrawal and underwhelming climate plans', available here.
• The explainer 'What is COP30 and why does it matter for the climate?, available here.
• The expert comment 'The UN climate process remains indispensable', available here.