Justice & Paix

Dr Luke Kemp is a Research Associate at the Centre for the Study of Existential Risk, University of Cambridge. He has a PhD in international relations from the ANU and previous experience as a senior economist at Vivid Economics. This episode explores catastrophic and extinction risk, why the topic is understudied, and how we can weigh out the catastrophic risks of climate change and solar geo-engineering.

Four key parts of the Earth’s climate system are destabilising, according to a new study with contributions from the Potsdam Institute for Climate Impact Research (PIK). Researchers analysed the interconnections of four major tipping elements: the Greenland ice sheet, the Atlantic meridional overturning circulation (AMOC), the Amazon rainforest and the South American monsoon system. All four show signs of diminished resilience, raising the risk of abrupt and potentially irreversible changes.

EU officials warn climate breakdown and wildlife loss ‘are ruining ecosystems that underpin the economy’ […] The European way of life is being jeopardised by environmental degradation, a report has found, with EU officials warning against weakening green rules. The continent has made “important progress” in cutting planet-heating pollution, according to the European Environment Agency, but the death of wildlife and breakdown of the climate are ruining ecosystems that underpin the economy.

Gains in cutting deaths from tuberculosis at risk as health officials warn clinics forced to ration drugs and testing

A team of researchers in California drew notoriety last year with an aborted experiment on a retired aircraft carrier that sought to test a machine for creating clouds.   But behind the scenes, they were planning a much larger and potentially riskier study of salt-water-spraying equipment that could eventually be used to dim the sun’s rays — a multimillion-dollar project aimed at producing clouds over a stretch of ocean larger than Puerto Rico.

Farming seaweed, changing ocean chemistry, breeding corals and restoring mangroves could help fight climate change – if assessed and managed responsibly.

2024 was the hottest year on record [1], with global temperatures exceeding 1.5 °C above preindustrial climate conditions for the first time and records broken across large parts of Earth’s surface. Among the widespread impacts of exceptional heat, rising food prices are beginning to play a prominent role in public perception, now the second most frequently cited impact of climate change experienced globally, following only extreme heat itself [2]. Recent econometric analysis confirms that abnormally high temperatures directly cause higher food prices, as impacts on agricultural production [3] translate into supply shortages and food price inflation [4, 5]. These analyses track changes in overall price aggregates which are typically slow-moving, but specific food goods can also experience much stronger short-term price spikes in response to extreme heat.

The constant deluge of bad news about rising global temperatures and their impacts can make it feel like the world is ending. Is it?

Research in Chile suggests climate crisis makes eruptions more likely and explosive, and warns of Antarctica risk

The world has been too optimistic about the risk to humanity and planet – but devastation can still be avoided, says Timothy Lenton

Ten kinds of possible collapses examined.

Tipping elements within the Earth system are increasingly well understood. Scientists have identified more than 25 parts of the Earth’s climate system that are likely to have “tipping points” – thresholds where a small additional change in global warming will cause them to irreversibly shift into a new state. The “tipping” of these systems – which include the Atlantic Meridional Overturning Circulation (AMOC), the Amazon rainforest and the Greenland ice sheet – would have profound consequences for both the biosphere and people. More recent research suggests that triggering one tipping element could cause subsequent changes in other tipping elements, potentially leading to a “tipping cascade”. For example, a collapsed AMOC could lead to dieback of the Amazon rainforest and hasten the melt of the Greenland ice sheet.

Lenton, the founding director of the Global Systems Institute at the University of Exeter, was the lead author of the 2008 paper that formally introduced the idea of tipping points in the Earth’s climate system.

The ocean ecosystem is a vital component of the global carbon cycle, storing enough carbon to keep atmospheric CO2 considerably lower than it would otherwise be. However, this conception is based on simple models, neglecting the coupled land-ocean feedback. Using an interactive Earth system model, we show that the role ocean biology plays in controlling atmospheric CO2 is more complex than previously thought. Atmospheric CO2 in a new equilibrium state after the biological pump is shut down increases by more than 50% (163 ppm), lower than expected as approximately half the carbon lost from the ocean is adsorbed by the land. The abiotic ocean is less capable of taking up anthropogenic carbon due to the warmer climate, an absent biological surface pCO2 deficit and a higher Revelle factor. Prioritizing research on and preserving marine ecosystem functioning would be crucial to mitigate climate change and the risks associated with it.

Antarctica's remote and mysterious current has a profound influence on the climate, food systems and Antarctic ecosystems. Can we stop it weakening by 2050?

A panel of international scientists has moved their symbolic “Doomsday Clock” closer to midnight than ever before, citing Russian nuclear threats amid its invasion of Ukraine, tensions in other world hotspots, military applications of artificial intelligence and the climate crisis as factors underlying the risks of global catastrophe.

Global risk management for human prosperity

A new report explores a framework for global climate risk management and includes contributions from an actuary at the Government Actuary's Department.

A new report from U.K. actuaries and climate scientists "shows a 50% GDP contraction between 2070 and 2090 unless an alternative course is chartered," said the lead author.​

The 20th edition of the Global Risks Report 2025 reveals an increasingly fractured global landscape, where escalating geopolitical, environmental, societal and technological challenges threaten stability and progress. This edition presents the findings of the Global Risks Perception Survey 2024-2025 (GRPS), which captures insights from over 900 experts worldwide. The report analyses global risks through three timeframes to support decision- makers in balancing current crises and longer-term priorities.