Global Warming

Evidence of Global Warming

There is clear, unequivocal evidence that the climate of the Earth is warming and has been doing so since at least the beginning of the 20th century. What is that evidence? How can we be sure that the Earth is actually getting hotter? The most often quoted and most intuitive of supporting data is the increase of surface temperature, worldwide. However, there are multiple sets of independent data that support the conclusion that the Earth's climate is warming.


The lines of evidence are as follows:

  • Tropospheric air temperature
  • Temperature over land
  • Atmospheric water vapor level
  • Marine air temperature
  • Sea surface temperature
  • Ocean heat content
  • Sea level
  • Sea ice area
  • High altitude snow cover
  • High latitude snow cover
  • Glacier volume
  • Permafrost

Global Land-Ocean Warming Data
(1880 to present)

Global Land-Ocean Temperature Estimates
Source: http://data.giss.nasa.gov/gistemp/graphs/
(click image to enlarge)

Since 1880 the average global temperature (land and ocean) has increased by approximately 0.85° C. The bulk of the energy that contributed to that warming has been absorbed by the oceans, with the rest warming the earth's atmosphere, land areas, polar ice sheets, and glaciers.


More information on climate change

Keeling Curve for CO2

(click image to enlarge)
Source: Keeling Curve - CO2 Atmospheric Concentration at Mauna Loa Observatory

The above chart shows the accelerating increase of carbon dioxide in the atmosphere since 1960. This increase can only be scientifically explained by the steady increase in carbon dioxide emissions from the burning of fossil fuels - coal, oil, and natural gas.