Staging a large event like Oympics has a huge environmental impact. You have to house people, transport them around, build venues, put on shows - all that consumes resources.

Previous Olympics were often criticised for the environmental damage they caused through waste, construction and transport. That?s why Environmental concerns and sustainability took a lead at the 2012 London Olympic Games. "Greener, cleaner and gentler" – that was the motto and   sustainability was at the heart of London's 2012 Olympics.

I was reading the fact and figures because of which London Olympics were known as Green Games. I would like to share them with you .

Aiming to cut the carbon footprint by 100,000 tonnes of carbon emissions in the procurement of materials and venue construction.There were five main themes of the 2012 London Games' environmental strategy: climate change biodiversity waste inclusion and healthy living.

Known as Green Games as they were the sustainable and most eco friendly games ever. To help save energy , visitors were encouraged to use public transport –underground train/popular tube , red double deckered buses  and even ferries along the river as a means of transport .

80,000-seat stadium as light in structure was not just the stadium, it was the velodrome . Stadium was built to hold 80,000 people . After the games , the top part was removed so as to hold 25,000 people. Lightest stadium ever built  with much of the construction material made of old gas pipes. To save on carbon emissions, 60% of building material was brought by rail or river. Massive 90% of construction waste was reused or recycled. To put it simply, it was a lightweight stadium and had a much smaller carbon footprint .

Moving to Aquatic center-roof was shaped like a wave and was 160 m long. It not only looked great but also served a green function. Rainwater was funnelled along the wave and was channelled and collected. All water was carefully used. Water from the swimming and diving pool was used to flush the toilets.

Before the building was erected , land was unloved and unwanted or derelict. The Olympic Park was praised for regenerating a derelict area and benefiting wildlife. The site of London's Olympic Park was appreciated for its radical transformation.

Thousands of trees were planted, rivers and grounds were cleaned up. Existing or temporary venues were used wherever possible. To be specific-At the largest urban park built in Britain in over the century, officials planted 2,000 native trees and 300,00 wetland plants and restored five miles of the River Lea. 110 acres of land were also turned into "reed beds, wet woodlands, grassland and ponds" to encourage the return of wildlife.

The cleanup process involved removing junk by hand and then decontaminating two million tons of soil using special "soil washer" machines. It was a win-win out [of] this re-use of soil on site because they din't have the [truck] movements back and forth. They din't send vast quantities of semi-contaminated soil to landfill sites around the country.

On a smaller scale, food vendors at the Olympic Park  used compostable packaging made mainly from starch and cellulose-based bio-plastics . Collaborations with suppliers Coca-Cola and Heineken elped to reduce waste with easier and more visible on-site recycling.

While British officials originally planned to draw 20 percent of the London Olympics' power from renewable sources, they fell short of that goal and  only nine percent of on-site energy was from renewable source.

I wish if all mega sports events embrace sustainability like this or may be more , it would drastically reduce the environmental impact of such huge scale events.