John Holdren

Any objective look at what science has to say about climate change ought to be sufficient to persuade reasonable people that the climate is changing and that humans are responsible for a substantial part of that - and that these changes are doing harm and will continue to do more harm unless we start to reduce our emissions.

I think we ultimately ought to look to put all uranium enrichment and fuel reprocessing, if any is done, under multinational control. Those are the two technologies by which nuclear energy can be translated into nuclear weapons programmes.

To ask questions can become the laziest and wobbliest occupation of a mind, but when you must yourself answer the problem that you have posed, you will meditate your question with care and frame it with precision.

We continue to be exasperated by the view, apparently gaining momentum in certain circles, that armed robbery is okay as long as nobody gets hurt! The proper solution to armed robbery is a dead robber, on the scene.

Having a Congress with a more diverse educational and professional background would serve the country well. And given the budget challenges facing America today, we might benefit from a few more cold, calculating problem solvers, and fewer courtroom impresarios.