Here is a picture I took at our regional landfill
If you were curious about back to school fashions in 1965- just have a look. I live in Seattle and our solid waste goes to a very well run landfill, operated by people who are consciously trying to do the right thing for our planet (http://your.kingcounty.gov/solidwaste/index.asp). Gas is collected at the landfill and used to generate energy. Landfill gas is touted as a source of green energy and often used as an excuse/ justification to landfill wastes that can produce gas. The gas in question is primarily methane (CH4). Methane is famous in the greenhouse gas world for having the 23 times the impact of CO2 on a 100- year basis. It only lasts in the atmosphere for 10 years so getting rid of it now has a potential for a big impact (https://www.britannica.com/science/greenhouse-gas). Methane is formed when microbes try to get energy from eating in an atmosphere without oxygen. Sanitary landfills typically fit that bill. The larger ones are required to collect methane. This was done primarily to prevent the gas from migrating from the landfill into the basements of neighboring homes. Methane is also full of energy and highly explosive. Lighting a cigar in the basement while watching the game before the regulations were put into place could have set off a very big bang. Captured, this gas is also known as natural gas and is a great source of energy.
The point of the picture though is that the newsprint in the landfill (and this is from a landfill cell made in 1965) does not decompose and does not generate methane.
Here is a picture of my food waste.
I took this right after breakfast. We had just cracked the eggs and peeled the grapefruit. The colors were vibrant. You could still tell what had been on the menu. By the next day the colors had faded but the smell had just started to ripen. If left in the bin the mold would have been in full bloom within the week. I am very lucky because I can put this into the compost bin that gets collected and taken to the compost facility once a week. If this had been taken to the landfill instead, you would not find any trace of the grapefruit in 50 days, let alone the 50 years that the newsprint had been sitting there.
Food waste contains all of the water and all of the nutrients, plus the carbon that the microbes in the landfill need to make a solid meal and plenty of methane. The problem is that food waste is so easy to decompose (just look in the back of your refrigerator) that the methane is formed long before the gas collection switch goes on. Landfilled food waste has a very high methane generation potential and that is why it is so bad to put food waste into them. The US EPA recently recognized this with a revision of their Waste Reduction Model, known as the WARM model (https://www.epa.gov/warm). In the new model landfilling food scraps generates about ¾ of a ton of CO2 for each wet ton. On a dry weight basis- that is more than 3 tons of CO2 per ton of scraps. If you take it to a compost facility instead- you get carbon credits for enriching the soil- 0.2 tons of CO2 credit for each ton of food scraps that are made into compost.
Plus if you use them in your garden you get a whole lot more food to eat next time around. Take my onions as proof.
If you want to compost your food scraps and collection isn't offered where you live- you can look for a compost facility here http://www.findacomposter.com/
You can also make your own or start a community compost pile- https://ilsr.org/initiatives/composting/