Tribute to Stephen Salter

A Tribute to Emeritus Professor Stephen Salter, MBE, FRSE


Stephen Salter, a remarkable pioneer and leader in solar geoengineering, passed away peacefully in his sleep at age 85 on February 23. As Professor of Engineering Design at the University of Edinburgh, he had a long history of provocative and innovative research, first in wave energy, designing the Salter Duck, and then in Marine Cloud Brightening. Stephen worked closely with John Latham and many other scientists to develop the MCB concept of submicron monodisperse sea salt generation, as proposed in their 2012 article published by the Royal Society. This article used general circulation model computations to argue that cooling from MCB could balance the heating from a doubling of CO2 while also delivering targeted local cooling.


Stephen was in excellent health until late last year, actively engaging in discussions about how to take forward his designs to test MCB. In 2023 he purchased a 3000 m2 engineering workshop in Loanhead to establish the Lothian School of Technology, where a number of his former engineering students are developing innovative technologies. The Lothian School will be used to research Stephen’s proposal for a spray tunnel to test wafer nozzle technology for the generation of submicron MCB salt spray, potentially in collaboration with the Cambridge University Centre for Climate Repair. Stephen established Ocean Cooling Technology Ltd as the owner of the Lothian School to take forward his vision.


He hoped to supervise a team of young engineers to work in R&D for MCB at the Lothian School, proving the concepts needed to eventually deploy his design for remotely controlled oceangoing MCB vessels. This technology was recently endorsed by Dr James Hansen et al in their celebrated article, Global Warming in the Pipeline, as the most innocuous way to research solar radiation management.


It was a source of immense frustration and regret for Stephen that the climate establishment treated him as a pariah due to his advocacy of planetary cooling. He was excluded from the British delegation to the Glasgow COP26 climate conference, prompting him to observe that just the security budget for that event could have been enough to start cooling the planet with MCB. Similarly, he compared the costs of World War Two warships against the transfer prices paid for top footballers as a model for MCB costs, to illustrate how badly humanity fails to get our priorities right. As Stephen explained in a 2022 interview with Nick Breeze, a primary constraint for effective action to mitigate climate change is lack of funding for MCB research. This situation highlights the need for media, academic and government discussion of the major planetary security and ecology risks created by the political refusal to allow action to reflect more sunlight.


Perhaps if more people had taken a scientific view on climate policy much of the extreme weather of recent years could have been mitigated with MCB, which offers the best available way to cut hurricane intensity, while also offering a rapid way to help refreeze the poles. Stephen had the foresight to arrange his affairs through the establishment of the Lothian School, so when humanity comes to reason and understands the urgent need to cool the planet, the technology could be well advanced to limit the ongoing damage of global warming.


Robert Tulip


NOTE: Find a Presentation by and Discussion with Stephen Salter here.