he global vision of the environment is changing. Electric cars, Synthetic fuels, Green Hydrogen, Biofuels$($including sustainable aviation fuels $$ SAF$),$ and of course $$Hydrogen$$ are being explored. Each has a specific$$area of application, but combined, can provide a synergistic approach. CO$2$ accounts for almost $80\%$ of$$global emissions with around $25\%$ is from Transport, and of that $10\%$ is from aviation.

a$)$ What commitments do the singapore changi airports need to make to enable operators to operate their aircraft there.