The climate is constantly changing, we can find evidence all around us of different climates of the past. In Greenland and Antarctica scientists drill deep for ice cores. The proportions of two forms of oxygen in water and gases trapped in tiny bubbles are clues to past temperatures and the broad changes over time in certain places.

The discovery of certain pollens can tell us whether the climate was warmer, colder, drier or wetter. Grains of plant pollen can survive for thousands of years and is a very accurate way of building a picture of past climatic conditions and phases. Coral reefs occur only in very clear seas 10-60 m deep, where the water temperature never falls below 20c. Because it is hard, dead coral is often preserved, find a fossil reef and you can be sure that once that place lay beneath a warm shallow sea. Many tiny animals and insects such as beetles are often preserved in the rock or soil to give us clues of the weather type many years ago.Next Week........Ocean Currents and Climate.Answer to last weeks question: Rock.This weeks question: Coral reefs occur where the water temperature never falls below: A/ 20c.B/ 18c.Best of Luck.Glossary:

Condensation: The change from gas to liquid.The weather for coming week: Monday 21st April-Friday 25th April.Low pressure to the south early this week will be replaced by high pressure from Wednesday onwards, with the weather turning warmer.Monday showers then drier later with sunshine.Tuesday mainly fair and warmer.Wednesday some rain about.Thursday and Friday odd shower otherwise dry, warmer with sunshine.Maximum temperature 16-18c 61-64f.Minimum temperature 7-9c 45-48f.Last Week's Observations (Monday-Sunday)Highest day temperature.........13.6c 57f on Monday 14th and Tuesday 15th April.Lowest night temperature.........Minus 1.1c 30f on Monday 14th April.Wettest day.............................7.8 mm on Tuesday 15th April.