With things set to really heat up next week at the Copenhagen climate summit, the Guardian runs down greenhouse gases you oughta know: 
 - Carbon dioxide (CO2): Industrialization and deforestation have produced high levels of this gas, which helps trap heat inside Earth’s atmosphere.
- Methane (CH4): Thirty times more dangerous than CO2, it’s mainly a byproduct of agriculture—think burping cows. But much less methane than carbon dioxide is produced.
 
                            
                            
                            
                            
                            
                                
                                
                                    
                                        
 - Nitrous oxide (N2O): Commonly called laughing gas, it’s the third-worst gas in terms of turning up the heat.
- Hydrofluorocarbons (HFCs): Used in cooling systems after chlorofluorocarbons were phased out, HFCs now cause 1% of warming and are being regulated, too.
- Perfluorocarbons (PFCs): Released in various manufacturing processes, these gases don’t ever really break down in the atmosphere.
 For the rest of the list, click the link at right.