The need for decarbonisation

The papers collated for this special issue of BSER&T explore the challenges and solutions associated with decarbonising buildings. Energy use in buildings accounts for around a quarter of global greenhouse gas emissions. To limit global warming to 1.5 C it is essential that buildings decarbonise rapidly. The coronavirus pandemic resulted in a reduction of global CO2 emissions of approximately 7 per cent in 2020. This 7 per cent reduction in emissions is comparable to that required every year for the next decade, to meet the Intergovernmental Panel on Climate Change (IPCC) pathway to limit the global rise in temperature to 1.5 C. Achieving this goal will require global improvements in construction standards and operational performance, and the wholesale retrofit of most of our existing building stock globally. There is a huge opportunity to deliver social and economic benefits through the creation of jobs which will stimulate the global economy while slowing the rate of climate change. Global economic modelling has repeatedly shown that it is cheaper to mitigate climate change through reduced emissions, than to attempt to adapt to its unmitigated effects. Economists largely agree that it is barely possible to quantify the wider cost of runaway climate change. An increase in global temperatures by 3 C or higher combined with an increase in the number and intensity of extreme weather events, sea level rise of five metres or higher, extensive biodiversity loss, and largescale population migration, is predicted to lead to widespread societal collapse. As such, inaction is not an option. If the IPCC carbon reduction trajectory is to be achieved, then simply complying with existing building standards is not sufficient. Governments, designers and building owners must identify a suitable low energy building specification to support rapid decarbonisation. Governments must revise regulations to align with the required rate of emissions reduction. Where this has yet to happen building owners should not wait for governments to move but should undertake their own analyses to establish the required specifications and implement them rapidly.