Computing the Climate: How we know what we know about climate change

Global climate models play a central role in climate science, drawing together broad inter-disciplinary teams to study how the atmosphere, oceans, ice sheets, and biosphere interact - and how their behaviours shift in response to changing levels of greenhouse gases. Yet few people outside the climate science community understand how these models are developed, tested, and used. In this talk, I will discuss my latest book, "Computing the Climate", which aims to fill this gap. The book is written in an accessible style, suitable for a general audience, and is based on my extensive visits to climate modelling labs, and interviews with dozens of climate modellers. The first half of the book traces the history of climate science, from the first attempts in the nineteenth century to calculate how the Earth's temperature would alter in response to changing levels of greenhouse gases, through to the birth of numerical weather forecasting and the discovery of chaos theory. The second half of the book describes the work of four different climate modelling labs (UKMO, NCAR, IPSL, and MPIM), which are used thematically to illustrate different aspects of modern climate modelling: the key design decisions when developing a global climate model; the challenges of coupling together models of different components of the climate system; the kinds of experiments these models support; and the processes by which they are tested and validated against observational data. The closing chapter summarizes what the models tell us about likely future climate change, and what will be needed to stay within the temperature thresholds adopted by the UN. I’ll end the talk with some thoughts about communicating climate science, and how we best to reach different audiences.                                                                                                                   Note that the book is available at a 20% discount from Cambridge University Press by using the code COMC2023 (See: http://www.cambridge.org/9781107589926).  Steve will also bring copies of his book if anybody wants to purchase (cash only)