Green Computing

1. I don't know anything about the topic, I've never even heard of the topic, I'm assuming it has something to do with ecology or environmental protection though.
2. My questions about the topic are basically this: If it is about the environment, how exactly is the environment helped or used in their computing? If not, what is the origin of the name "Green Computing"?
3. http://searchdatacenter.techtarget.com/definition/green-computing
http://www.explainingcomputers.com/green.html
http://www.techopedia.com/definition/14753/green-computing
http://green.wikia.com/wiki/Green_Computing
4. Things I learned about the topic

1. The name "green" actually does come from ecology, since green computing is the environmentally responsible use of computers
2. Mostly, their goals are reducing the consumption of energy and other resources, and disposing of e waste in responsible ways
3. The origins of green computing originate in Energy Star, founded by the EPA in 1992 to promote efficient energy consumption
4. It takes about 1.8 tons of chemicals, water, and fossil fuels to produce one single desktop computer
5. Over 1 billion PCs have been sold worldwide
6. It is estimated that by 2020, computers in the UK will amount to two-thirds of its energy consumption

This topic connects with my life because although I don't put so much importance to environmental stuff normally, I do use my laptop a lot, and that entails also charging it.

What actions could I take, I wonder, to reduce energy consumption in terms of buying hardware?