The amount of greenhouse gas generated per pound of beef depends a lot on how the cows were raised. An important study from this year (here's the link: study ) shows that the emissions can range from -3.5 net emitted kg CO₂ per kg of beef (which indicates carbon sequestration rather than emission) to 33 kg CO₂ per kg of beef.

In the first case, the cows were raised in an integrated system called "regenerative grazing". The cows were allowed to graze on large plots of land, and were cycled around the land so that they would turn up the dirt with their hooves and fertilize (or poop) right on the dirt. Then, they were followed by chickens and goats who also turned up the dirt and fertilized it. In this way, carbon was captured by the raising of the animals, because they churn the dirt with their hooves and integrate their manure, and then the dirt becomes healthy soil to grow more plants. Carbon is released by the cows and their manure, as well as during transport, but more carbon is sequestered in the dirt than is released in the atmosphere in this style of grazing.

In the case where the production of beef emitted 33 kg CO₂ per kg of beef, the cows were raised in a practice called "conventional intensive production". In this case, cows live on feedlots and are usually fed grains and corn that were shipped into the feedlot. Then, the cows defecate right on the feedlot, and the manure is cleaned up and set aside in a large pile where it rots (rather than fertilizing the ground). In this method, carbon is released into the atmosphere when the feed is shipped to the feedlot, when the cows defecate, and when their manure rots, as well as during slaughter and transportation of the cows. This is a much more intensive method of producing beef, and releases a lot more carbon than the regenerative grazing approach. Grass fed beef, which falls between these two approaches, will have less emissions than the conventional approach and more emissions than the regenerative grazing approach.

Also, to help with your conversions:
1 kg CO₂ per 1 kg beef = 1 lb CO₂ per 1 lb beef,
1 kg CO₂ per 1 kg beef = 0.45 kg CO₂ per 1 lb beef.

Well, you can try to calculate it. Beef is meat, and so are you. How much food do you eat in a day? How long would it take you to eat an amount of food equal to the mass of your body? Then, how many years have you been alive?

I would guess that you've produced about 30 times the mass of your body in carbon dioxide over the course of your life, based on all the food that you have eaten and burned. Cows do the same thing.

That depends on how the cattle are raised. Here's an article that says how complicated this is:
read here.

Here are 2 answers to your question, from this article. (1 kg [kilogram] is about 2 pounds.)
1. Organic beef produced in Sweden (22.3 kg of carbon dioxide-equivalent GHG emissions per kilogram of beef)

2. Unusual and resource-intensive Kobe beef production in Japan (36.4 kg of CO₂-equivalent GHG emissions per kilogram)

And here's a number for typical beef from the U.S.:
3. According to several analyses, typical nonorganic beef production in the United States results in only 22 kg of CO₂-equivalent GHG emissions per kilogram of beef, which is 0.3 kg less than the Swedish organic beef system.