Observed changes in concentrations of greenhouse gases in the atmosphere

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1. Man-made climate change?
Observed changes in concentrations of greenhouse gases in the atmosphere
Observed changes in the Earth’s climate
The inertia of the climate system
Feedback effects
Abrupt changes
Worksheet 1.1
Worksheet 1.2
2. What will a warmer world be like?
Changes in different parts of the world
The Intergovernmental Panel on Climate Change (IPCC)
Future emissions and climate change
Vulnerability and adaptation
Worksheet 2.1
Worksheet 2.2
3. How can we hinder man-made climate change?
More emissions despite improved technology
Emissions trading in the EU
The Climate Convention (The UNFCCC)
The Kyoto Protocol
Worksheet 3.1
Worksheet 3.2
Observed changes in concentrations of greenhouse gases in the atmosphere
- Carbon dioxide (CO2) has increased from 280 ppm (280 litres of CO2 in a million litres of air) in the period 1000 to 1750 to about 370 ppm today. This is about a 31% increase and today’s levels are the highest atmospheric CO2 concentrations in at least 420,000 years, probably 20 million years.
- Methane (CH4) has increased from 0.7 ppm in 1750 to 1.7 ppm in 2000. This is an increase of about 151%.
1. Increase in greenhouse gas concentrations (in ppm) from 1750 to 2000. Graphics: Elmar Uherek
- Nitrous oxide (N2O) has increased from 0.27 ppm in 1750 to 0.32 ppm in 2000. This is about a 17% increase.
- Tropospheric ozone (O3) has increased by about 35% from 1750 to 2000. This figure, does however, vary from region to region. Ozone in the lower atmosphere is a greenhouse gas, it is formed and broken down by chemical reactions in the atmosphere, and humans emit other substances which influence these chemical reactions.
(Source: IPCC 2001 and http://cdiac.esd.ornl.gov/pns/current_ghg.html).
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About this page:
Author: Camilla Schreiner - CICERO (Centre for International Climate and Environmental Research - Oslo) - Norway.
Scientific reviewers: Andreas Tjernshaugen - CICERO, Norway - 2004-01-20 and Dr. Knut Alfsen - Statistics Norway, Norway - 2003-09-12.
Educational reviewer: Nina Arnesen - Marienlyst School, Oslo, Norway - 2004-03-10.
Last update: 2004-03-27.
Last modified: Friday, 17 May 2019, 4:30 PM