Intergovernmental Panel on Climate Change

advises the United Nations on the Framework Convention on Climate Change

IPCC findings on climate change (1995)


Summary for Policy makers



Concentrations | Findings | Human influences | Definitions | Sources | Reports

"Increases in greenhouse gas concentrations since pre-industrial times have led to a positive radiative forcing of climate, tending to warm the surface and produce other changes in climate."

• Many greenhouse gases remain in the atmosphere for a long time (for Carbon dioxide and Nitrous oxide many decades to centuries, hence they affect radiative forcing on long time-scales."

• The atmospheric concentration of greenhouse gases (measured in 1992)

      1. Carbon dioxide; 30% increase
      2. Methane; 145% increase
      3. Nitrous oxide, 15% increase

have grown significantly:

• These trends can be attributed largely to human activities, mostly fossil fuel use, land-use change and agriculture.

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At any location year-to-year variations in weather can be large, but analyses of meteorological and other data over large areas and over periods of decades or more have provided evidence for some important systematic changes.

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Concentrations | Findings | Human influences | Definitions | Sources | Reports

The balance of evidence suggests a discernible human influence on global climate.

· The 20th century global mean temperature is at least as warm as any other century since at least 1400 AD.

· The observed warming trend is unlikely to be entirely natural in origin.

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Current: IPCC findings | Third Assessment | Fourth assessment | Fifth Assessment


Archer | Archer conclusion | Christianson | Crowley | Gelbspan | James Hansen, 04 : Hansen 06 | McKibben| Musil | Schmidt | Weart | Wigley


Gale Christianson | Jeremy Leggett | Larry Lohmann | Contemporary

Fourth Assessment Report, 2-2007


 Radiative forcing is defined as the simple measure in Watts per square meter of the perturbation to the energy balance of the Earth's atmosphere. It is a measure of the potential for climate change.

* Approved meaning a "report has been subject to detailed, line-by-line discussion and agreement in a plenary meeting of the relevant IPCC working group." of specialists in the field.

Periodically the Intergovernmental Panel on Climate Change, IPCC, offer's scientific reports. These began with the First Assessment Report [AR1], in 1990.

These dates are:

  • AR1, 1990
  • AR2, 1995
  • AR3, 2001
  • AR4, 2007
  • AR5, 2013, the most recent.
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    Intergovernmental Panel on Climate Change, UNEP & WMO, Climate Change 1995: The Science of Climate Change, Cambridge, U.K.: The Cambridge University Press, 1996, pp. 3-7.

    Other sources.

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