Research does not mean deployment, and I fully hope that we will be able to reduce our emissions without ever needing Solar Radiation Management. You can't avoid doing the wrong thing until you've researched what the wrong thing is.

Dr Hugh Hunt

The SRM Science 2015 conference was held at the Department of Engineering to look at the science behind one particular avenue of research - Solar Radiation Management (SRM). Most at the conference agreed that there is an urgent need for research into SRM, even if many – including the Conference Chair, Dr Hugh Hunt – hope that it will never need to be deployed.

Hugh, a senior lecturer in the Department, said: "Climate engineering is not a get out of jail free card. But time is running out and we cannot delay carrying out research. Without it, there is a real danger that governments will be forced into making decisions about climate engineering without proper understanding of the science.

"Some say that we're not ready to have this conversation, but I say we have to – we must not aspire to be ignorant of the facts. But research does not mean deployment, and I fully hope that we will be able to reduce our emissions without ever needing Solar Radiation Management. You can't avoid doing the wrong thing until you've researched what the wrong thing is."

Scientists and engineers at the conference investigated four key areas of science:

• Session 1: Climate modelling which looked at the results of existing climate models and tried to identify major sources of uncertainty.
• Session 2: Impacts, implications and consequences, looked at changes in the earth's energy balance by SRM and how they will affect the earth's ecosystem through second-order effects acting on the hydrological cycle, carbon cycle and ecosystems.
• Session 3: Engineering systems examined the feasibility and costs of infrastructure and technology that would be needed to realize SRM proposals such as surface albedo modification, space reflectors, reflective aerosols and saltwater sprays.
• Session 4: Atmospheric chemistry looked at what we know about changes to the composition and chemistry of the atmosphere and clouds caused by particle injection by means of observations of natural phenomena (such as volcanic eruptions and cloud formation), lab measurements and computer modelling.

These questions, and many others raised by the prospect of climate engineering, involved diverse ethical, social, political and technical issues which are both complex and interlinked.

The four sessions at the conference were interspersed with keynote lectures from leading scientists, and a panel discussion that examined topics such as trust, justice, intention and responsibility. With accountability and reflectiveness woven into every session, this conference provided a forum for participants to discuss the practicalities of SRM, with a particular focus on identifying the 'known unknowns' and future research priorities.

Some believe that climate engineering is already being covertly implemented through chemicals added to aviation fuel, producing so-called 'chemtrails'. Hugh elaborated:
"I am unaware of any evidence that chemtrails are being generated, and I very much doubt it's happening. In any case climate engineering by injection of particles in the atmosphere at 30,000 feet wouldn't even be effective."

The SRM Science 2015 conference followed on from the Berlin CEC14 conference last August which aimed to engage in critical global discussions by bringing together the research, policy and civic communities to discuss the highly complex and interlinked ethical, social and technical issues that come into focus when discussing climate engineering. It was clear from the discussions in Berlin that climate engineering is a diverse and complex field, and the two types of climate engineering - carbon dioxide removal (CDR) and solar radiation management (SRM) each have their own particular technical, social, ethical and political issues.