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.
The chart with the sum of carbon dioxide emissions (carbon footprint ) therefore shows the accountability for the current situation.