Before you can start calculating your personal carbon footprint, you must create a user account on http://timeforchange.org. Don't worry, your email address won't be given away or misused.
The attached Excel sheet can be used to calculate both CO2 emissions as well as primary energy requirements for the following activities:
Run your own simulations of global warming with the attached spreadsheets!
Is prevention of global warming possible? Or is only mitigation of global warming possible? How fast do changes in the carbon dioxide emissions affect the average temperature increase? What are the effects of some proposed global warming solutions?
The following graph shows the cumulative CO2 (carbon dioxide) emissions by country for the years 1900 until 2002. This is the sum of all CO2 emissions in the years 1900 until 2002 for each developed country. Data source was the World Resources Institute (WRI).
On the page link here, you can find the CO2 emissions by country and/or per capita by country .
It does make sense to look at the sum of all CO2 emissions because the lifetime of the greenhouse gases like CO2 in the atmosphere is between 50 and 200 years. The current global warming is an effect of all greenhouse gases put in the atmosphere during the last 100 years, global warming is not just caused by the greenhouse gases emitted this year or last year! This is also one of the reasons why immediate action is required to reduce the emission of greenhouse gases like carbon dioxide, because the effects of the greenhouse gases will last for about 100 years.
A carbon footprint is defined as:
The total amount of greenhouse gases produced to directly and indirectly support human activities, usually expressed in equivalent tons of carbon dioxide (CO2).

The graph shows the total CO2 emission in million tons by country for the year 2002. Data source was the World Resources Institute (WRI). The CO2 emissions for the year 2006 are about 12 to 15% higher than the figures shown here.
The second chart shows the CO2 emissions by capita and country for the year 2002. Data source was again the World Resources Institute (WRI). Some remarks to these values:

Global warming is a typical global phenomena, where the causer of the emission does not automatically suffer from it himself. Cause and effect are separated both in time as well as with regard to geography.
In the past, there was a more or less direct relation between the energy consumption (mainly fossil fuels) and the welfare of a country.
This makes it very difficult to reach consensus between the countries about the required steps to solve the problem. The Kyoto protocol shows that the following of the agreement will be doubtful at best if no automatic sanctions take into effect for countries violating it.
Given the severe consequences of global warming, the above sounds quite hopeless for our future. Read on to see how we all are involved in this and how we can benefit from taking our personal responsibility.