How we calculated global clinical trial greenhouse gas emissions

Healthcare Without Harm worked with consultancy Arup to estimate that global health systems spend $7.2tn annually and are responsible for 4.4% of global greenhouse gas emissions, around 2.0 gigatonnes of carbon dioxide equivalent (CO2e). Statista.com estimates the global pharma industry spend on clinical research to be $198b and a 2016 paper in BMC Medicine from RAND Europe indicates that, for the UK at least, the private sector is funding 54% of the total research effort. Total research funding then would be about $370bn, 5.1% of the total global spend on healthcare. This would indicate clinical research might be responsible for around 100 megatonnes CO2e emissions per year.