Sea Level

• This resource includes two graphs that show the rate at which sea levels are rising. 
• One graph is based on more recent satellite data, and the other includes historical measurements going back to 1900. 
• Students will learn that sea level rise is caused by melting land ice and the expansion of water molecules as seawater warms. 

Positives

• The graphs are easy to read and understand.
• Students can click and drag on the graph to view a zoomed-in view of a specific period.
• The graph that depicts data from 1900 to 2020 indicates sources that have caused an increase in sea level with a plus (+) sign and sources that have caused a decrease in sea level with a minus (-) sign.
  

Additional Prerequisites

• Students should understand how to read a line graph.
• Some students might not understand what the ± (plus-minus sign) means (e.g., sea level rise is 98 ± 4 mm). This is the uncertainty margin. That means that there is a high probability that the true number is within that range. For more information about the uncertainty margin, hover over the "i" icon on the left side of the page to the right of the latest measurement.

Differentiation

• Geography and social studies classes could discuss how sea level rise results in unequal effects on various populations, particularly those in low-lying coastal areas or islands.
• Students could discuss the factors that cause sea levels to increase and decrease and discuss how those factors might inform climate action aimed at keeping sea levels low.  
• Other resources on this topic include this video on thermal expansion and sea level rise, this interactive map of areas that will be impacted by sea level rise, and this article on the effect of rising seawater on groundwater resources.

The resource tracks sea levels starting in 1993. It is instructive and will deepen students' understanding of climate controls such as melting ice sheets, glaciers, thermal expansion, and its impact on the rising sea level globally. This resource is valid and recommended for teaching.