“Pulverized willow bark,” replied her fairy godmother.

“What happened to the carpet?” she asked.

“The carpet was nylon, which is made from butadiene and hydrogen cyanide, both made from petroleum,” came the response.

Greta smiled, acknowledging that adjustments are necessary to save the planet, and moved to the sink to brush her teeth where instead of a toothbrush, she found a willow, mangled on one end to expose wood fibre bristles.

“Your old toothbrush?” noted her godmother, “Also nylon.”

“Where’s the water?” asked Greta.

“Down the road in the canal,” replied her godmother, ‘Just make sure you avoid water with cholera in it”

“Why’s there no running water?” Greta asked, becoming a little peevish.

“Well,” said her godmother, who happened to teach engineering at MIT, “Where do we begin?” There followed a long monologue about how sink valves need elastomer seats and how copper pipes contain copper, which has to be mined and how it’s impossible to make all-electric earth-moving equipment with no gear lubrication or tires and how ore has to be smelted to a make metal, and that’s tough to do with only electricity as a source of heat, and even if you use only electricity, the wires need insulation, which is petroleum-based, and though most of Sweden’s energy is produced in an environmentally friendly way because of hydro and nuclear, if you do a mass and energy balance around the whole system, you still need lots of petroleum products like lubricants and nylon and rubber for tires and asphalt for filling potholes and wax and iPhone plastic and elastic to hold your underwear up while operating a copper smelting furnace and . . .

“What’s for breakfast?” interjected Greta, whose head was hurting.

“Fresh, range-fed chicken eggs,” replied her godmother. “Raw.”

“How so, raw?” inquired Greta.

“Well, . . .” And once again, Greta was told about the need for petroleum products like transformer oil and scores of petroleum products essential for producing metals for frying pans and in the end was educated about how you can’t have a petroleum-free world and then cook eggs. Unless you rip your front fence up and start a fire and carefully cook your egg in an orange peel like you do in Boy Scouts. Not that you can find oranges in Sweden anymore.

“But I want poached eggs like my Aunt Tilda makes,” lamented Greta.

“Tilda died this morning,” the godmother explained. “Bacterial pneumonia.”

“What?!” interjected Greta. “No one dies of bacterial pneumonia! We have penicillin.”

“Not anymore,” explained godmother “The production of penicillin requires chemical extraction using isobutyl acetate, which, if you know your organic chemistry, is petroleum-based. Lots of people are dying, which is problematic because there’s not any easy way of disposing of the bodies since backhoes need hydraulic oil and crematoriums can’t really burn many bodies using as fuel Swedish fences and furniture, which are rapidly disappearing – being used on the black market for roasting eggs and staying warm.”

This represents only a fraction of Greta’s day, a day without microphones to exclaim into and a day without much food, and a day without carbon-fibre boats to sail in, but a day that will save the planet.