Green IT describes a movement in the IT industry towards sustainable and renewable energy sources, as well as increased productivity and efficiency resulting in decreased consumption and wastage in fulfilling the role of Information Technology across all industries.
While the jury is still out on Global Warming and/or its causes, Climate Change seems to be an increasingly undeniable fact. Climate Change is defined as the decreasing of air quality, changes in weather patterns and magnitude of severity of natural disasters. Many scientists argue that these facts are quite evident based on statistical analysis of historical weather patterns. 
In any case, humans are clearly impacting the Earth by their existence (whether that impact is good or bad is subject to debate). As a result, we have a problem in that the world is an ecosytem based on finite resources.
Green IT may very well be one of the most significant
Although there are a number of possible approaches and technological innovations which could lead humanity towards a greener future through IT, it is almost inarguable that the greenest (that is, most environmentally friendly and impact-minimizing) method for reducing the global carbon footprnt of IT is through Telecommuting.
Telecommuting (that is working from remote locations where physical presence is not necessary) . Telecommuting tends to reward employees for intellectual contributions rather than physical presence, and focuses on capabilities rather than credentials of an individual.
Removing the commute to a single centralized place of work from the daily schedule of IT workers can increase productivity, decrease each employee's carbon footprint by reducing their dependence on gasoline and other non-renewable fuel sources, and reducing the burden on employers to provide a massive infrastructure for their workers to operate in. It also tends to free workers to contribute to projects from their prefered locations, meaning they are much more comfortable and therefore productive, provided that an efficient mechanism is in place for minimizing the impact of distractions.
Mobile Data Centers
Mobile Data Centers are any data centers who can have their geographic location shifted based on energy, logistic or other organizational needs. A common vision is the "Green IT" Data Center vision where, through a cloud computing platform or other network and/or controller virtualization architecture, a company or organization's data center would have its location follow the source of available sustainable and/or renewable energy sources. For example:
--> The sun rises in the east of the country so an organization's smaller data centers in the east would handle the majority of the network accesses running on sustainable solar energy every morning, but as the sun travels across the country during the day, the computing capabilities are gradually shifted towards the western data centers, and eventually "handed off" completely as the sun sets in the eastern locations (most workers would go home at this time anyway). For the most part, the data center's computing capability could remain in the western data centers until the next morning, where the same process repeats itself.
--> Similar to the example above, data centers' computing resources could follow weather patterns, for example, in cases where data centers are geographically dispersed in areas where it is possible to harness wind or tidal power. When one area is experiencing high wind and thus high power throughput, the IT center could be shifted there, and when the wind shifts direction the nearest data center could take over. If there is no data center that can supply the necessary sustainable power at a given time, a fallback would be set in place of centers which can provide tidal power, geo-thermal, solar or in the final case, a typical electricity plant.
As with most innovations, Green IT innovations may have both positive and negative side-affects. It is always important to weigh the costs of introducing a new technology against the risks of negative side-affects that its introduction could cause. 
For fiscal year 2008-09, NRC allocated approximately $2.2M in operating and $2.0M in capital funding to 11 institutes to help support their contributions to the projects. They are:
- Chemical and ethanol production from lignocellulosic materials derived from forestry or agricultural biomass: http://zone.nrc-cnrc.gc.ca/research/programs/npethanol_e.html
- Use of biomass and municipal waste to produce energy and chemicals through anaerobic digestion and gasification: http://zone.nrc-cnrc.gc.ca/research/programs/npbiomass_e.html
- Biomaterials and biopolyols for the production of environmentally-friendly products for the automotive, aerospace, construction and plastics industries: http://zone.nrc-cnrc.gc.ca/research/programs/npbiomat_e.html
- Establishing a Canadian capacity to produce biofuels from marine algae: http://zone.nrc-cnrc.gc.ca/research/programs/npbiofuels_e.html
- ENERGY STAR: http://www.energystar.gov/
- Big bucks riding on data -- Leaked e-mails cast doubt on global-warming strategy: http://www.torontosun.com/comment/columnists/lorrie_goldstein/2009/11/25/11915496-sun.html
- Hide The Decline (hide the decline): http://www.smalldeadanimals.com/archives/012722.html
- CRU Ringleader Phil Jones to Step Down over ClimateGate: http://www.infowars.com/cru-ringleader-phil-jones-to-step-down/
- Gibbs -- Despite research dispute, ‘climate change is happening’: http://thehill.com/blogs/blog-briefing-room/news/69797-gibbs-despite-research-dispute-climate-change-is-happening
- Bombshell UN Documents Outline Plan To Use Climategate Crooks In “End Run” Around National Sovereignty : http://www.infowars.com/bombshell-un-documents-outline-plan-to-use-climategate-crooks-in-end-run-around-national-sovereignty/
- Post on GreenITers: http://www.greeniters.com/profiles/blogs/climategate-implications-on/
- Making "Vermicompost Tea" (purifying and removing chlorine from tap water for plants): http://brainseed.blogspot.com/2008/07/making-vermicompost-tea.html
- Seven androids – and their lessons for enterprise IT: http://news.zdnet.co.uk/emergingtech/0,1000000183,39532961,00.htm
- Down on the server farm: http://www.economist.com/opinion/displaystory.cfm?story_id=11413148
- Buy our stuff, save the planet?!?: http://www.economist.com/opinion/displaystory.cfm?story_id=11412495&CFID=6880639&CFTOKEN=91727492
- The Search for Change: http://online.wsj.com/article/SB123654827391164761.html
- Green Energy - Following the evolution of clean, renewable sources of energy: http://greenenergy.amplify.com/
- Robin Chase (founder of ZipCar and GoLoco) on the (Financial) Value of Sharing: http://www.good.is/post/robin-chase-on-the-financial-value-of-sharing/
- Maybe The Recession Wasn’t So Bad -- Cloud Commuting: http://www.elance.com/p/blog/2009/07/maybe_the_recession_wasnt_so_bad_after_all.html?rid=1JY2W
- Solar Power for the World: http://www.vizworld.com/2009/09/solar-power-for-the-world/?utm_source=sidebar&utm_medium=popular&utm_campaign=layout
- Will e-bikes be the new 'commuter cool'?: http://www.cnn.com/2009/TECH/10/15/electric.bicycles/index.html?eref=rss_topstories
- Green Tech Investment in India – Is it really happening?: http://www.pluggd.in/funding/green-tech-investment-startups-in-india-is-it-really-happening-1434/
- India Green Building: http://greentechnolog.com/country/india/
- Green IT/Broadband and Cyber-infrastructure Blog: http://green-broadband.blogspot.com/
- Water refineries?: http://www.eurekalert.org/pub_releases/2008-07/nsf-wr_1072808.php
- MIT splits water with sunlight: http://www.tcetoday.com/tcetoday/NewsDetail.aspx?nid=10724
- 'Major discovery' from MIT primed to unleash solar revolution: http://web.mit.edu/newsoffice/2008/oxygen-0731.html
- Power Generation -- Researchers achieve solar power ‘nirvana’: http://www.energyefficiencynews.com/power-generation/i/844/
- Reference Needed
- Mysterious Explosion 1,000 Times Greater than Hiroshima: http://www.environmentalgraffiti.com/featured/mysterious-explosion-1000-times-greater-hiroshima/3589