Climate Change Evidence

• How have annual global temperatures changed in recent years?

  They have been increasing.
• What does the increase in annual global temperatures provide evidence for?

  It provides evidence for climate change.
• What year was the warmest globally since 1880?

  2010.
• What do scientists predict about global temperatures in the future?

  They predict that temperatures will continue to rise rapidly.
• What are the three pieces of evidence for climate change?

  • Rising sea levels
  • Glacial retreat
  • Decreasing ice and snow cover
• What is the evidence for rising sea levels in relation to climate change?

  Global sea levels rose by about 14 cm.
• How has the rate of rising sea levels changed over the past 50 years?

  They are rising faster than they were 50 years ago.
• What does the glacial retreat evidence indicate about climate change?

  Glaciers have been retreating at double the rate in the last 9,500 years.
• What does the decreasing ice and snow cover evidence show about climate change?

  The extent and thickness of Arctic sea ice has been rapidly declining in recent decades.
• How many record-low levels of snow did North America see between June 2008 and 2012?

  Three record-low levels.
• What methods can be used to collect evidence for climate change?

  • Pollen analysis
  • Ice cores
  • Tree rings
• How does pollen analysis provide evidence for climate change?

  Each plant produces pollen grains with a unique shape, preserved in sediment cores.
• What can scientists determine from pollen grains preserved in sediment cores?

  They can determine the abundance and type of vegetation growing, indicating past climate conditions.
• How do ice cores provide evidence for climate change?

  Ice cores contain bubbles of air from when the ice was formed, which can be sampled to determine greenhouse gas levels.
• What do the bubbles in ice cores indicate?

  They indicate levels of greenhouse gases in the atmosphere at the time the ice was formed.
• How do tree rings provide evidence for climate change?

  Tree rings grow wider in warm, wet years and thinner in cold, dry years.
• What can scientists gather from compiling tree ring data?

  They can gather evidence of how the climate has changed over hundreds of years.