How much time does a plastic bag take to decompose?

We often use the word bio-degradable these days. But what does degradation mean in terms of time? So recently I found this list of items and the amount of time they take to decay, decompose, degrade.

Banana Peel- 3-4 weeks
Orange peels- 6 months
Apple Core- 2 months
Paper Bag- 1 month
Cardboard- 2 months
Newspaper- 6 weeks
Paper Towel- 2-4 weeks
Cotton Glove- 3 months
Tinned Steel Can- 50 years
Aluminum Can- 200-500 years
Disposable Diapers- 550 years
Plastic Bags- 20-1000 years
Glass- 1-2 million years
Leather shoes- 25-40 years
Rubber-Boot Sole- 50-80 years
Plastic containers- 50-80 years
Foamed Plastic Cups- 50 years
Wool Sock- 1-5 years
Plywood- 1-3 years
Plastic Bottles- 450 years

Signature campaign to save Pune's hills

The schedule for signature campaign till 18th Nov.
Pl do inform all and be present in large numbers to save our hills.

16th Nov - Morning 7am - Model Colony - Chitranjan Vatika

16th Nov - Evening 5pm - FC Road - Opp Vaishali

17th Nov - Morning 7am - Prabhat Road - KNP

17th Nov - Evening 5pm - Taljai - Taljai Hill top

18th Nov - Morning 7am - Vetal Tekdi - ARAI

18th Nov - Evening 5pm - Aundh - Ozone Mall

Green Pune Movement: The hills of Pune need your help

"Why no construction should be allowed on the hills?

Construction on hills means cutting into the hill for building foundations. This sets off a chain reaction developing cracks in the rock strata. This leads to a weakening of the hills because the microscopic cracks allow water and air to penetrate. The heating and cooling of water and air leads to widening of cracks and speeds up decay of rock converting it into soil. Since there are no trees or grasses the soil starts getting washed off leading to mudslides and landslides. This causes destruction of environment as well as property standing on this land. It can also cause death of innocent people as it did in the case of Chatushrungi landslide the year before last. We are now in seismic zone three. This means that we can expect an earthquake anytime. The weakening of hills will lead to major disaster in case of earthquake.

Also as per the norms, for a good breathing conditions, there has to have atleast 12 sq. m. area of forested land per person. Considering that population of Pune is approximately 4 million, we need to have atleast 4800 hectors of green area. Even after accounting the regular parks, private parks and nala garden or riversides, we still have deficit of about 1600-1800 hectors. This type of land is available only on hills today. Hence hills must be kept as green zone and not construction zone. It is fundamental right of citizens of Pune. " - Quote from Green Pune Movement Member