Ben McKnew writes from Pasadena: "Is it possible to see the jet stream, maybe in the clouds? How wide is it? ... Where do you stand on global warming?" In 85 words? Sheesh ... Jet streams are too high (six to nine miles) and too wide (200 to 300 miles) to be discerned from the ground. Global warming? There's little scientific doubt the planet is warming, and humans play a role. The debate is over rates, consequences and what we should do about it.