New Evidence for Climate Change

• Evidence collected by NASA shows that average temperatures have risen by 0.6 since 1950.
• Arctic sea ice has declined by 10% in the last 30 years.
• Evidence from the IPCC has shown that average global sea levels have risen by 10 - 20 cm in the last 100 years. This is due to thermal expansion and sea ice melting.
• What is thermal expansion?

  The increase in size or volume of a substance when its temperature increases.
• Thermal expansion causes an increase in sea level as warmer water takes up more space than colder water.
• As sea ice melts, there are fewer reflective surfaces which means more solar radiation can be absorbed into the ocean causing further warming.
• Sea ice melts because it absorbs less heat energy compared to open water so it doesn't warm up as quickly.
• Global mean surface temperature (GMST) refers to the average temperature across all land and oceans on Earth.