how many tons of co2 are entering the atmosphere on an annual basis?

Answer 1

Carbon Dioxide from Power Plants
About 40% of U.S. carbon dioxide emissions stem from the burning of fossil fuels for the purpose of electricity generation. Coal accounts for 93 percent of the emissions from the electric utility industry. US Emissions Inventory 2004

Coal emits around 1.7 times as much carbon per unit of energy when burned as does natural gas and 1.25 times as much as oil. Natural gas gives off 50% of the carbon dioxide, the principal greenhouse gas, released by coal and 25% less carbon dioxide than oil, for the same amount of energy produced. Coal contains about 80 percent more carbon per unit of energy than gas does, and oil contains about 40 percent more. For the typical U.S. household, a metric ton of carbon equals about 10,000 miles of driving at 25 miles per gallon of gasoline or about one year of home heating using a natural gas-fired furnace or about four months of electricity from coal-fired generation.

Carbon Dioxide Emitted from Cars
About 20% of U.S carbon dioxide emissions comes from the burning of gasoline in internal-combustion engines of cars and light trucks (minivans, sport utility vehicles, pick-up trucks, and jeeps).US Emissions Inventory 2004 Vehicles with poor gas mileage contribute the most to global warming. For example, according to the E.P.A's 2000 Fuel Economy Guide, a new Dodge Durango sports utility vehicle (with a 5.9 liter engine) that gets 12 miles per gallon in the city will emit an estimated 800 pounds of carbon dioxide over a distance of 500 city miles. In other words for each gallon of gas a vehicle consumes, 19.6 pounds of carbon dioxide are emitted into the air. [21] A new Honda Insight that gets 61 miles to the gallon will only emit about 161 pounds of carbon dioxide over the same distance of 500 city miles. Sports utility vehicles were built for rough terrain, off road driving in mountains and deserts. When they are used for city driving, they are so much overkill to the environment. If one has to have a large vehicle for their family, station wagons are an intelligent choice for city driving, especially since their price is about half that of a sports utility. Inasmuch as SUV's have a narrow wheel base in respect to their higher silhouette, they are four times as likely as cars to rollover in an accident. [33]

The United States is the largest consumer of oil, using 20.4 million barrels per day. Senator Joseph Lieberman says, "If we can get 3 miles more per gallon from our cars, we'll save 1 million barrels of oil a day, which is exactly what the (Arctic National Wildlife) Refuge at its best in Alaska would produce." [81]

If car manufacturers were to increase their fleets' average gas mileage about 3 miles per gallon, this country could save a million barrels of oil every day, while US drivers would save $25 billion in fuel costs annually.

Carbon Dioxide from Trucks
About another 13% of U.S carbon dioxide emissions comes from trucks used mostly for commercial purposes.[20]

Carbon Dioxide from Airplanes
The UN's Intergovernmental Panel on Climate Change estimates that aviation causes 3.5 percent of global warming, and that the figure could rise to 15 percent by 2050.

Carbon Dioxide from Buildings
Buildings structure account for about 12% of carbon dioxide emissions.

Methane
While carbon dioxide is the principal greenhouse gas, methane is second most important. According to the IPCC, Methane is more than 20 times as
effective as CO2 at trapping heat in the atmosphere. US Emissions Inventory 2004 Levels of atmospheric methane have risen 145% in the last 100 years. [18] Methane is derived from sources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel production. Most of the world’s rice, and all of the rice in the United States, is grown on flooded fields. When fields are flooded, anaerobic conditions develop and the organic matter in the soil decomposes, releasing CH4 to the atmosphere, primarily through the rice plants. US Emissions Inventory 2004

Nitrous oxide
Another greenhouse gas is Nitrous oxide (N2O), a colourless, non-flammable gas with a sweetish odour, commonly known as "laughing gas", and sometimes used as an anaesthetic. Nitrous oxide is naturally produced by oceans and rainforests. Man-made sources of nitrous oxide include nylon and nitric acid production, the use of fertilisers in agriculture, cars with catalytic converters and the burning of organic matter. Nitrous oxide is broken down in the atmosphere by chemical reactions that involve sunlight.

Deforestation
After carbon emissions caused by humans, deforestation is the second principle cause of atmospheric carbn dioxide. (NASA Web Site) Deforestation is responsible for 25% of all carbon emissions entering the atmosphere, by the burning and cutting of about 34 million acres of trees each year. We are losing millions of acres of rainforests each year, the equivalent in area to the size of Italy. [22] The destroying of tropical forests alone is throwing hundreds of millions of tons of carbon dioxide into the atmosphere each year. We are also losing temperate forests. The temperate forests of the world account for an absorption rate of 2 billion tons of carbon annually. [3] In the temperate forests of Siberia alone, the earth is losing 10 million acres per year.

City Gridlock
Cities are tolerating gridlock. In 1996 according to an annual study by traffic engineers [as reported in the San Francisco Chronicle December 10, 1996] from Texas A and M University, it was found that drivers in Los Angeles and New York City alone wasted 600 million gallons of gas annually while just sitting in traffic. The 600 million gallons of gas translates to about 7.5 million tons of carbon dioxide in just those two cities.

Carbon in Atmosphere and Ocean
The atmosphere contains about 750 billion tons of carbon, while 800 billion tons are dissolved in the surface layers of
the world's oceans. World Resources Institute

Answer 2

The real question is where the excess heat trapped by an ever thickening blanket of greenhouse gases goes. The atmospheric temperatures have risen far less than the CO2 index would indicate...and this confuses a lot of people. The short answer is in the physics. Heat moves from warm to cool. It moves from a less dense medium to a more dense medium. The 'more dense medium' is ice first and sea water second. Massive amounts of ice are now melting as this medium absorbs the atmospheric heat. Ocean temperatures are very slowly rising as well. Right there you have your cause and effect. Trapped heat is the 'cause', melting ice and warming sea water is the 'effect'. Put you warm beer cans in your ice chest. The beer cools as the ice absorbs the heat energy and melts. The cause of the melting ice is the warm beer and the leakage of warm air into the container. Any 'scientist' who 'believes' in the reverse isn't really a 'scientist'.

Answer 3

Over the past forty years, about 482 billion metric tons of CO2 have appeared in the atmosphere, an average of about 12 billion tons per year. The CO2 released by human activity has been estimated at 16.5 billion tons per year; indicating a significant absorption of CO2 by the oceans, which contain some 144,700 billion metric tons of CO2. This far exceeds the total atmospheric content of CO2, which is about 2,875 billion metric tons.
-- Robert A. Saunders, Lake Stevens, WA.

Answer 4

About 6,000,000,000 metric tons per year.

Answer 5

http://www.realclimate.org/index.php?p=87