I swore I'd never be caught dead here - after giving it a go, it's my worst nightmare

Having long sworn I'd never be caught dead on a cruise ship, I've been obliged to swallow my words to board the 20-deck, 170-ton, 6,000 people-carrying NCL Encore in Seattle to watch my son Henry Shine performing in the musical The Choir Of Man. We sailed the Alaskan coast, watched for whales and visited the threatened Glacier Bay National Park. It was both thrilling and my worst nightmare.

My 4,000 mostly wealthy and loud American fellow passengers aside - I wilt in crowds and am not partial to feeding-time buffets - I was forced to confront facts of life that left me uncomfortable. Such as? The questionable labour practices of the industry: mostly mixed multiple-ethnic domestic, hospitality and service staff, while officers, crew and cast are predominantly white; waste and pollution; shore visits that overwhelm quaint towns with thousands of tourists who contribute insignificantly to the local economy; and above all, appalling ecological interference.

The effect of human-caused climate change viewed at point-blank range is devastating. In this, the UN-declared Year of International Glacier Preservation, to face these slow-advancing, fast-receding, majestic masses of rock, ice and snow is to confront evidence that climate change truly exists.

Of the 200,000 glaciers on Earth, a third are predicted to disappear by 2050. Given our planet is warming faster than ever, many won't make it that far. Since 1900, the global sea level has risen by eight centimetres.

It may not seem like much but consider that Alaska's Juneau Icefield is melting five times more rapidly today than it did during the 1980s.

Reduced land mass will not only deprive many species of territory to live on, but millions of human beings of drinking water. The Alaskan coast is one of the world's most popular cruise destinations.

To observe glaciers and marine life before they vanish is truly a privilege affordable to few. But at what price?

How many of those entitled passengers, as they tear up to the observation deck before dawn to bag the prime viewing spots, stop to think about what a cruise ship leaves behind: toxic sewage, used bathroom and laundry water, bilge, exhaust gases including nitrogen oxide and the many wasted breakfasts, lunches, teas and dinners recycled as "fish food" - a vile cocktail of sugar, pesticides, hormones and antibiotics that lead to the disruption of entire ecosystems.

The critically endangered North Pacific right whales will soon be extinct. The fish will all be Type 2 diabetic and glaciers will be a distant memory. But Kayleigh from Kentucky will be tickled pink for life knowing that she was one of the last to see them.