Doesn't the driver ( and any passengers ) in the car emit CO2 as well, so you are not comparing like with like.
You must compare CO2 from Car, driver and passengers with CO2 emitted by cyclist to be more accurate.
You will need to divide the CO2 for car driver and passenger by number of occupants of car to get CO2 per person per journey
350 kg
A Bugatti Veyron produces around 596 grams of CO2 per kilometer driven.
Burning 1 kg of LPG produces approximately 2.98 kg of CO2.
Burning 1 kg of petrol produces around 2.3 kg of CO2.
An average car produces about 7700 kg of co2 a year.
Burning one liter of furnace oil produces approximately 2.6 kg of CO2 emissions.
When 1 liter of ethanol (C2H5OH) is burned, it produces about 1.5 kilograms of carbon dioxide (CO2). This calculation is based on the complete combustion of ethanol, which releases approximately 3.0 kilograms of CO2 for every kilogram of ethanol burned. Given that 1 liter of ethanol weighs about 789 grams, this results in the release of CO2 from the carbon content in the fuel.
A bike produces no direct CO2 emissions while being ridden, as it is powered by human effort. However, the production and transportation of the bike may contribute to CO2 emissions depending on the manufacturing process and materials used.
Yeast
cell respiration consumes oxygen and sugars and produces CO2, photosynthesis consumes CO2 and produces oxygen and sugars
A car running on petrol or diesel produces 3¼ lbs of CO2 for every 1 lb of fuel used. The extra weight comes from oxygen taken in through the air filter to burn the fuel. A typical car running 12,000 miles per year and using 300-400 gallons of fuel produces 3 to 4 tons of CO2 in that time.
60% of crude oil imported into the US is burned as fuel (cars, trucks, power plants). One barrel of crude oil makes about 317 kg of CO2. The US consumes about 9,286,000 barrels/day (of gasoline, assuming it produces the same CO2 per barrel...). One average person produces about 0.90 kg of CO2 per day. The US alone produces the CO2 of 2.9 trillion people. China has the US beat on the production of CO2 also.