Walsh said the European Union should use its emissions trading scheme as a fore-runner for a global programme but not attempt to drag in non-EU airlines lest they take legal action.

Euler equations of generalized Riemann variable are derived from unsteady primitive variable Euler equations and solved by using two - a point-two-step upwind finite difference method.

This paper puts forward the comparative coefficient way in solving two special type of Euler equations, which can make it more simple and convenient to use.