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Write down 5 key words to summarise these pictures.Global warming introLearning outcomes

All of you should be able to:Identify the different greenhouse gases (GHGs)

Most of you should be able to:Describe the role of greenhouse gases (GHGs) in maintaining mean global temperature.Describe how human activities add to greenhouse gases (GHGs)Greenhouse gasesWhich of these gases are greenhouse gases? water vapour (H2O)carbon dioxide (CO2)methane (CH4) nitrous oxides (N2O)ozone (O3) CFCs (Greenhouse gases) trap the radiation from the sun that is reflected back from the Earth.

Greenhouse effect

Source: Solcomhouse.comAbout 45% of the incoming light is reflected before it reaches the surface.51% is absorbed by Earths surface and 4% is reflected.The Greenhouse EffectEssential for life to exist on the planet.Without it the planet would be 33C cooler.

HOWEVER As humans increase emissions of some GHGs the greenhouse effect is exaggerated or enhanced. Most climate scientists believe that this is causing global warming and climate change.RecallDescribe the greenhouse effect?

Explain the process?

Give 3 examples of a greenhouse gas.

The concentration of carbon dioxide in the atmosphere from 1958-2004http://gu.com/p/3fyeq

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carbon dioxidetemperatureAs you can see...global temperatures are rising!

NASAs Goddard Institute for Space Studies. (2006) Global temperature change. Proc. Natl. Acad. Sci. 103: 14288-14293. Following the common practice of the IPCC, the zero on this figure is the mean temperature from 1961-1990.

Changes in carbon dioxide concentrations during the Phanerozoic era. Three estimates are based on geochemical modelling: GEOCARB III (Berner and Kothavala 2001), COPSE (Bergmann et al. 2004) and Rothman (2001). These are compared to the carbon dioxide measurement database of Royer et al. (2004) and a 30 Ma filtered average of those data. Error envelopes are shown when they were available. The right hand scale shows the ratio of these measurements to the estimated average for the last several million years (the Quaternary). Courtesy: Robert A. Rohde, Global Warming Art

The observed sea ice in 1979 and 2003

Jacabamba Glacier, Peru, in 1980 (left) and 2002 (right)Explanations for these trends?The onset of global industrialisation and pollution derived from fossil fuelsDeforestation (particularly of rainforest)Volcanic activitySunspot activityAssume a link between carbon dioxide emissions and temperature increaseSuggest possible natural phenomena that may have increased temperatures.16Think, pair, shareWhat do you think are the main human activities releasing GHGs?

Hint: use your knowledge of what the main GHGs are.

The direct warming influence of all long-lived greenhouse gases in the atmosphere today attributable to human activities.

CO2s warming influence of 1.7 watts/m2 is equivalent to the heat from nearly 9 trillion 100-watt incandescent light bulbs placed across Earths surface.

The combined influence of the non-CO2greenhouse gases is equivalent to the heat from about 5 trillion bulbs. The category other includes a few very long-lived chemicals that can exert a climate influence for millennia.(Credit: NOAA - National Oceanic and Atmospheric Administration)Checking outcomesAll of you should be able to:Identify the different greenhouse gases (GHGs)

Most of you should be able to:Describe the role of greenhouse gases (GHGs) in maintaining mean global temperature.Describe how human activities add to greenhouse gases (GHGs)Confirm you know themWhat are 4 greenhouse gases?

Describe how GHGs maintain the mean global temperature?

List at least 4 human activities that add to GHGs.

Describe how each one adds to GHGs.