1. Feedbacks and forcing Looking Down on Earth
Clouds and sunlight over the Indian Ocean, as seen from Discovery during the STS-96 mission in Image Credit: NASA
© Nuffield Foundation 2009

2. Three main factors affecting the greenhouse effect
Factors influencing the greenhouse effect. (2002). In UNEP/GRID-Arendal Maps and Graphics Library. Retrieved 16:44, July 21, 2009 from
Factors influencing the greenhouse effect. There are three main factors that directly influence the energy balance of the earth: the total energy influx, which depends on the earth's distance from the sun and on solar activity; the chemical composition of the atmosphere, and albedo, the ability of the earth's surface to reflect light. The only factor that has changed significantly in the last 100 years is the chemical composition of the atmosphere.
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3. Ice, snow and the albedo effect
Climate change - ice and snow and the albedo effect. (2008). In UNEP/GRID-Arendal Maps and Graphics Library. Retrieved 11:57, July 31, 2009 from
Climate change - ice and snow and the albedo effect. Changes in the polar regions can cause more warming in the entire planet earth system through feedback effects. One such effect is the reduction of ice and snow due to warmer temperatures. When the white and gray snow and ice disappears, less sun rays are reflected out and instead the energy is absorbed by land and sea - which causes further increase in the warming.
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4. Feedbacks in the climate system
Climate feedbacks - the connectivity of the positive ice/snow albedo feedback, terrestrial snow and vegetation feedbacks and the negative cloud/radiation feedback. (June 2007). In UNEP/GRID-Arendal Maps and Graphics Library. Retrieved 16:13, July 21, 2009 from
Climate feedbacks - the connectivity of the positive ice/snow albedo feedback, terrestrial snow and vegetation feedbacks and the negative cloud/radiation feedback. Feedback refers to the modification of a process by changes resulting from the process itself. Positive feedbacks accelerate the process, while negative feedbacks slow it down. Part of the uncertainty around future climates relates to important feedbacks between different parts of the climate system: air temperatures, ice and snow albedo (reflection of the sun’s rays), and clouds. An important positive feedback is the ice and snow albedo feedback. Sea ice and snow have high albedo. This means that they reflect most of the solar radiation. With warmer polar temperatures, the area of sea ice and snow cover decreases, exposing new expanses of ocean and land surfaces that absorb an increased amount of solar radiation. This increase of total absorbed solar radiation contributes to continued and accelerated warming.
© Nuffield Foundation 2009

5. Three main factors affecting the greenhouse effect
Factors influencing the greenhouse effect. (2002). In UNEP/GRID-Arendal Maps and Graphics Library. Retrieved 16:44, July 21, 2009 from
Factors influencing the greenhouse effect. There are three main factors that directly influence the energy balance of the earth: the total energy influx, which depends on the earth's distance from the sun and on solar activity; the chemical composition of the atmosphere, and albedo, the ability of the earth's surface to reflect light. The only factor that has changed significantly in the last 100 years is the chemical composition of the atmosphere.
© Nuffield Foundation 2009

6. Factors contributing to climate forcing
Global average radiative forcing estimates and ranges in 2005 for anthropogenic greenhouse gases and other important agents and mechanisms compared to pre-industrial times.
Understanding global warming requires understanding the changes in climate forcings that have occurred since the industrial revolution. These include positive forcing from increased greenhouse gases, negative forcing from increased sulfate aerosols and poorly constrained forcings from indirect aerosol feedbacks as well as minor contributions from solar variability and other factors. The poorly constrained aerosol effects results from both limited physical understanding of how aerosols interact with the atmosphere and limited knowledge of aerosol concentrations during the pre-industrial period. This is a significant source of uncertainty in comparing modern climate forcings to past states.
Contrary to the impression given by this figure, it is not possible to simply sum the radiative forcing contributions from all sources and obtain a total forcing. This is because different forcing terms can interact to either amplify or interfere with each other. For example, in the case of greenhouse gases, two different gases may share the same absorption bands in the electromagnetic spectrum thus partially limiting their effectiveness when taken in combination.
Credit:
This figure was produced by Leland McInnes (Radiative-forcings.svg) using gnuplot and Inkscape and is licensed under the GNU Free Documentation License. All data is from publicly available sources. Downloaded feom Wikipedia Commons.
© Nuffield Foundation 2009

7. The carbon cycle
The carbon cycle. (2000). In UNEP/GRID-Arendal Maps and Graphics Library. Retrieved 16:24, July 21, 2009 from
The carbon cycle. The global carbon cycle shows the carbon reservoirs in GtC (gigatonne= one thousand million tonnes) and fluxes in GtC/year. The indicated figures are annual averages over the period 1980 to The component cycles are simplified and the figures present average values. The riverine flux, particularly the anthropogenic portion, is currently very poorly quantified and is not shown here. Evidence is accumulating that many of the fluxes can fluctuate significantly from year to year. In contrast to the static view conveyed in figures like this one, the carbon system is dynamic and coupled to the climate system on seasonal, interannual and decadal timescales.
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8. Image created by Robert A. Rohde / Global Warming Art: http://www
This figure shows the history of atmospheric carbon dioxide concentrations as directly measured at Mauna Loa, Hawaii. The longest such record exists at Mauna Loa, but these measurements have been independently confirmed at many other sites around the world.
The annual fluctuation in carbon dioxide is caused by seasonal variations in carbon dioxide uptake by land plants. Since many more forests are concentrated in the Northern Hemisphere than the Southern Hemisphere, more carbon dioxide is removed from the atmosphere during Northern Hemisphere summer than during Southern Hemisphere summer. This annual cycle is shown in the inset figure by taking the average concentration for each month across all measured years. This cycle is sometimes referred to as the "breathing" of the Earth.
The red curve shows the average monthly concentrations, and blue curve is a moving 12 month average.
© Nuffield Foundation 2009

9. Trends in carbon dioxide concentrations and temperatures
Historical trends in carbon dioxide concentrations and temperature, on a geological and recent time scale. (June 2007). In UNEP/GRID-Arendal Maps and Graphics Library. Retrieved 15:59, July 21, 2009 from
Historical trends in carbon dioxide concentrations and temperature, on a geological and recent time scale. The most recent geological history, in the last hundred thousand years, has been characterised by cycles of glaciations, or ice ages. The historic temperatures, through these times, have been low, and continental ice sheets have covered large parts of the world. Through ancient air, trapped in tiny bubbles in the Antarctic ice, we have been able to see what the temperature cycle was at that time, and also the concentration of carbon dioxide (CO2). The more recent history, from the middle ages and up until now, show increasing temperatures, rising as the world emerged from the Little Ice Age (LIA), around With the industrial era, human activities have at the same time increased the level of carbon dioxide (CO2) in the atmosphere, primarily through the burning of fossil fuels.
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10. Global influences and effects
Climate change global processes and effects. (2008). In UNEP/GRID-Arendal Maps and Graphics Library. Retrieved 16:32, July 21, 2009 from
Climate change global processes and effects. Climate change global processes and effects involving human activities, main climate features and major threats.
© Nuffield Foundation 2009