Is superfast really better? An airliner that can reach six times the speed of sound is being made, but some worry that it is not good news for the planet.
2030 forecast: travel goes hypersonic

Glossary
Hypersonic - Travelling at speeds of more than five times the speed of sound (Mach 5).
London - The capital city of the United Kingdom. It has a total population of 14 million.
New York - A city in the USA. It is in a state also called New York.
Sonic boom - A loud explosive sound caused by shockwaves created when an object travels faster than the speed of sound.
Scotland - A country that is part of the United Kingdom. It covers the northern part of the island of Great Britain.