It's been a beautiful autumn here in Denmark. Warm, with golden sun, blue skies, red and yellow and orange leaves on the trees. Just gorgeous. And unusually warm for Denmark. It's always exciting when, instead of wearing your winter coat every day from October to April, you can wear it every day from November to April.

But this unusually pleasant weather can't help but spark conversation about global warming. So far the biggest impact climate change has had in Denmark are some severe rainstorms, when end up flooding a lot of basements and overwhelming a lot of sewer systems. It's intriguing to think that plumbers may become the great heroes of the twenty-first century.

Danes care about climate change, and they've made a business specialty of green technology, or what they like to call clean technology. Cleantech. It sells windmills to create windpower, and burns most of its household garbage in an environmentally friendly way, to create home heating.

Danes care about the environment because they care about nature. Less than a hundred years ago, Denmark was a mostly agricultural country, and Danes still feel close to the land. Children in Denmark are constantly being taken out into whatever forests or meadows are nearby – in the cities, they pack them onto buses and trains to go get the forest experience. There's even something called forest kindergarten for children age 3 to 6. If you go to a forest kindergarten, you're out in the woods every day, hot or cold, rain or shine.

So it's ironic, given this love for the Earth and the environment, that the Danes were recently named the world's fourth biggest polluters, per capita, by the World Wildlife Fund. Only three Middle Eastern countries. – Kuwait, Qatar, and the UAE, were worse.