evidence of climate change

• What is climate change?

  Climate change is any significant change in the Earth's climate over a long period.
• What is the Quaternary period?

  The Quaternary period is the most recent geological time period, spanning from about 2.6 million years ago to the present day.
• What significant events does the Quaternary period include?

  The Quaternary period includes the whole of human history.
• What was the Earth's climate like before the Quaternary period?

  Before the Quaternary period, the Earth's climate was warmer and quite stable.
• How has the global temperature shifted during the Quaternary period?

  During the Quaternary, global temperature has shifted between cold glacial periods that last around 100,000 years and warmer interglacial periods that last around 10,000 years.
• How many glacial-interglacial cycles have occurred during the Quaternary period?

  There have been at least 20 glacial-interglacial cycles throughout the Quaternary period.
• What has been the trend in global climate since the end of the last glacial period?

  Since the end of the last glacial period, the climate has been warming.
• What is global warming?

  Global warming is the term used to describe the sharp rise in global temperatures over the last century. It's a type of climate change.
• How can scientists study past climate change?

  Scientists can study past climate change using methods such as ice and sediment cores, temperature records, pollen analysis, and tree rings.
• How are ice cores used to study past climates?

  Ice sheets are made up of layers of ice, with one layer forming each year. Scientists drill into ice sheets to extract long cores of ice and analyse gases trapped in the layers to study climate changes over thousands of years.
• What information has been found from an ice core in Antarctica?

  An ice core from Antarctica shows temperature changes over the last 400,000 years.
• How do sediment cores help scientists study climate change?

  Cores taken from ocean sediments contain the remains of organisms, which can be analysed to extend the temperature record back at least 5 million years.
• Since when have global temperatures been accurately measured using thermometers?

  Since the 1850s, global temperatures have been accurately measured using thermometers.
• What other historical records help extend temperature records further back?

  Historical records like harvest dates and newspaper weather reports can extend the temperature record further back.
• How does pollen analysis help scientists study past climates?

  Pollen from plants is preserved in sediments like lake beds or peat bogs. Scientists identify and date the preserved pollen to show which species lived at that time, indicating similar climate conditions.
• How do tree rings provide evidence of past climate conditions?

  Trees form a new ring each year, with thicker rings in warm, wet conditions. By counting rings and measuring their thickness, scientists can determine the tree's age and past climate conditions.
• How reliable are tree rings as evidence of past climate change?

  Tree rings are a reliable source of evidence for climate change over the past 10,000 years.