Improving home energy efficiency has a huge environmental impact. That's why we most of us started doing this work, after all. (Making homes more comfortable and helping people save money turn out to be a pretty terrific side benefits.)

Still, it's easy to get discouraged. If you do, take a look at the Mother Nature Network's quick look back at the past four decades of America's modern environmental movement. We've come a long way since the first Earth Day on April 22, 1970!

It’s been 43 years since the first Earth Day. On that day – April 22, 1970 – 20 million Americans took to streets, parks, and auditoriums across the country to demonstrate for a healthy, sustainable environment. It was the birth of a movement that continues to challenge the status quo and push us to take responsibility for our impact on the environment.

Looking for ways to celebrate Earth Day?

Put the Earth Day Forum at the top of your list. Hosted by the Midcoast Green Sneakers Project this Thursday, April 18, 7-8:30, at Rockland City Hall, the Forum offers an opportunity to hear about weatherization and energy efficiency, straight from the horse's mouth.

Have you seen the series of ads from Allstate that focus on worst-case-scenario home situations in order to emphasize the importance of a good home insurance policy? There are a number of ads in the series, but the one that caught our attention focuses on water heaters.