Cutting household ventilation to improve energy efficiency

If global emissions of greenhouse gases continue on their present trajectory, the Intergovernmental Panel on Climate Change (IPCC) projects that the world may be more than 4°C warmer in 2100 than in 1861-80.1 To hold warming to less than 2°C on average, the level often cited as the threshold of dangerous climate change, emissions must be reduced radically. For example, the World Bank estimated that global emissions would need to be halved by 2050, and continue falling thereafter, to reach this goal.2 The prospect is daunting, but there are many opportunities for intervention. Housing is a good example, as Milner and colleagues point out in the linked paper (doi:10.1136/bmj.f7493).3 The sector typically contributes about a quarter of national greenhouse emissions, energy efficiency is often low, and measures such as insulation can improve building performance quickly. We also know that well designed interventions to make homes warmer and safer can reduce energy use and improve health.4

However, energy efficiency measures may damage health if not done well. Milner and colleagues point to one health risk: an increase in indoor radon levels in homes …