| A | B | 
|---|
| Population size | Getting bigger at a faster and faster rate | 
| Food production | Needs to be increased to keep a larger population alive | 
| Waste removal | Needs to be increased to keep a growing population.  Perhaps using landfill sites. | 
| Energy | Bigger populations need more of this.  Providing it using up fossil fuels and causing pollution. | 
| Pest control | Biological or chemical destruction of harmful insects | 
| Ladybirds | Both adults and larvae eat aphids | 
| Parasitic wasps | Their larvae grow inside living caterpillars | 
| Biological control | Using predators or parasites to kill harmful insects | 
| Insecticide | Chemicals used to kill harmful insects | 
| Herbicide | Chemicals used to kill weeds | 
| Selective | A chemical which only kills the organisms you want to kill | 
| Resistance | What pests develop, faster than we can think of new pesticides | 
| DDT | Chemical which was used as a pesticide and is now banned because it builds up in top consumers and kills them too | 
| Pollination | A job done by bees.  Its a shame pesticides have killed millions of them | 
| Fruit | Only made by fruit trees which have been pollinated | 
| Sulphur dioxide | Recats with rain to produce sulphuric acid | 
| Nitrogen oxides | Recat with rain to produce nitric acid | 
| Coal fired | Power stations which cause most acid rain | 
| Power stations | Source of most sulphur dioxide | 
| Nuclear | Type of power station which produces no harmful gases but produces radioactive waste | 
| Acid rain | Caused by sulphur dioxide and nitrogen oxides when they react with water | 
| Fish eggs | Don't hatch in acidified lakes | 
| Greenhouse effect | Caused by carbon dioxide and methane | 
| Limestone | A sedimentary rock, destroyed by acid rain | 
| Carbon dioxide | A greenhouse gas absorbed by trees | 
| Methane | A flammable greenhouse gas produced by cattle | 
| Increase | What will happen to the sea level due to the greenhouse effect | 
| Polar ice caps | Melting, due to the greenhouse effect | 
| Gulf stream | An ocean current which may be diverted by the greenhouse effect.  The UK would then get colder. | 
| Extinction | What will happen to lots of organisms if the climate changes | 
| Atmosphere | Where greenhouse gases build up | 
| Long wave | Radiation trapped by greenhouse gases | 
| Short wave | Solar radiation which passes straight through greenhouse gases | 
| Ultraviolet | A cancer causing, short wave radiation from the sun | 
| Infra red | The proper name for long wave heat radiation | 
| Endangered | Animals which are close to extinction | 
| Conservation | The process of trying to manage habitats to stop organisms dying | 
| Medicine | Useful chemicals found in many tropical plants | 
| Deforestation | What is happening to many tropical forests | 
| Logging | Type of organisation which make most money from destroying tropical rainforests |