How hot could the world get?

Despite the conveniences of modern life and a plethora of opportunities for enjoyment, there is a prevailing sense of pessimism about the future. Climate change continues to worsen, with 2024 breaking temperature records. Scientists are working hard to develop accurate climate models to predict how much hotter our world will get, but differing assumptions lead to varied predictions. This uncertainty adds to the anxiety about the Earth's future while efforts to promote optimism seem more challenging. As human activity increasingly impacts the planet, understanding climate change and its trajectory remains critically important for us to navigate our future responsibly and sustainably. As this affects not just our environment but also emotional well-being, it is key to foster a balance between awareness and hope as discussions about our planet’s future continue.

Clouds play a complex role in climate change, both reflecting heat into space and trapping it on Earth, leading to varied predictions about future warming. Different climate models yield different estimates, ranging from two to six degrees of warming with significant implications for survival, technology, and planning. Policymakers require accurate forecasts to prepare for the future. However, there's a challenge in evaluating models, as many are treated equally despite differences in quality and sophistication. The IPCC combines predictions into a range, leaving uncertainty about which models are best. Thus, understanding which models to trust is crucial for effective responses to climate change and for ensuring a livable future.

Collaboration among countries in scientific models benefits climate predictions. Different models excel in various aspects like temperature or precipitation, and combining them often leads to better forecasts than using any single model. Recently, however, some models—called hot models—are predicting extreme warming scenarios, stirring debate within the scientific community. This emphasizes that while diverse voices and approaches improve science, the reliability of models can vary. Ultimately, blending insights provides clearer expectations of climate change, even if some extreme cases remain possible. This collaborative approach aims to assure countries and researchers of plausible outcomes while navigating the complexities of climate science.

Climate models predict significant global warming if carbon dioxide levels double, with some models anticipating over five degrees of warming. Their predictions vary based on factors like cloud cover and aerosols. Concerns about these so-called 'hot models' have led to debates over geoengineering solutions, which carry risks. Recently, scientists challenged these models' accuracy by seeing how well they simulate past temperatures. The IPCC adjusted their strategy by weighting models based on this accuracy, rather than averaging them indiscriminately. This means the models that performed well in replicating historical data are given more importance in future climate forecasts, ensuring more reliable predictions.

Climate models used to predict future weather outcomes, like temperature and rainfall, can show varying results. The IPCC chose to weigh these models differently based on past performance, which concerns some scientists, like Neil Swart. He believes this could limit the diversity of predictions, as different models excel in different areas. If overemphasis is placed on successful models, it might lead to a false sense of certainty. Outlier models, although they may seem less credible, remind us of the inherent uncertainty in climate predictions. For future reports, the approach to model weighting might need re-evaluation to ensure all perspectives are considered, allowing for more robust predictions. Scientific debate is crucial here, as varied conclusions reflect the complexity of climate science. Balancing model performance with model diversity will be essential to accurately forecasting climate change impacts.

This episode of the show was produced by a dedicated team, including Umar Irfan and Bird Pinkerton, with contributions from several others like Noam Hasenfeld, who hosts, and Christian Ayala, who handles sound design. They express gratitude to various individuals for their support and invite listeners to engage by asking questions or suggesting future episode topics. For those who appreciate the podcast, they encourage joining Vox's membership program or leaving a positive review, as both actions significantly help support their journalism efforts. They also mention that Unexplainable is part of the Vox Media Podcast Network and promise to return with more content next week.