Telegraph: Prince Charles will say that the need to tackle global warming is more urgent than ever before and that, even in a global recession, the world must not lose sight of the “bigger picture”. His warning will be delivered on Thursday in a keynote speech in Rio de Janeiro. Aides believe it will echo one he gave in Sao Paulo in 1991 at the start of the last recession, when he warned that caring for the world’s long term welfare must not become a “luxury”. The intervention will …