The Azimuth Project
Global warming (Rev #29)


This page is an overview page for human-caused global warming due to carbon emissions and other greenhouse gases.


In the later half of the 19th century scientists noticed that the Earth’s atmosphere kept it warm. In 1859, John Tyndall discovered that two major atmospheric gases H2O and CO2 could trap heat like the glass in a greenhouse. In 1896, Svante Arrhenius in Stockholm calculated that the burning of coal could increase the temperature of the Earth by 5-6°C if CO2 levels were doubled. At the rate of burning in 1896, this would have taken thousands of years.

Rising CO2e concentrations:

Mauna Loa CO2
Image source: Global Warming Art (click for data details)

Current CO2 concentrations compared to those over the last 400,000 years. This graph shows several glacial cycles:


Rising temperatures:

GISTEMP temperature data

Possible effects of various CO2e concentrations Carbon dioxide equivalent:

Stern Review graphic

For a quick overview, here are some graphs and charts. Click on them for the sources and more information.

Estimates of the relation between CO2e concentrations and temperatures:

CO2-temperature relation

The decline in Arctic sea ice:

Arctic sea ice levels

Some other relevant Azimuth Library links for global warming:

  • Reports and assessments - a list of reports and assessments on global warming, and
  • Plans of action - a list of detailed plans for dealing with global warming, and critiques of these plans.


From Carbon in the Geobiosphere:

Figure shows the growth of world population in 200 years, from 1800 to 2000, and the growth of CO2 emissions from fossil fuel burning and land-use practices. In this period, the global population increased 6-fold, but the industrial and land emissions increased 20-fold. The logarithmic scale of the figure shows that the population growth rate became faster in 1900 and again in 1950, following the end of World War II. However, the CO 2CO_2 emissions were growing faster than the population even in the 19th century and their growth accelerated further in the 20th.

pop vs co2 levels


The greenhouse effect caused by CO 2CO_2 has been a topic of scientific discussions for 200 years now, beginning with Fourier in 1827. The following volume collects some relevant papers that have been published in the course of time:

  • David Archer (Editor), Ray Pierrehumbert (Editor): The Warming Papers, Wiley-Blackwell 2011.

The physicist and science historian Spencer Weart has compiled an online history of global warming, which has also been condensed in book form.

category: climate, carbon