Climate Change Indicators to Know for AP Environmental Science

Climate change indicators reveal critical shifts in our environment, highlighting rising temperatures, increasing greenhouse gases, and melting ice. These changes impact ecosystems, weather patterns, and human life, emphasizing the urgent need for awareness and action in environmental science.

1. Global surface temperature trends

   • Average global temperatures have increased by approximately 1.2°C since the late 19th century.
   • The last decade was the warmest on record, indicating a clear upward trend.
   • Rising temperatures contribute to more frequent and severe heatwaves.

2. Atmospheric greenhouse gas concentrations

   • Carbon dioxide (CO2) levels have surpassed 400 parts per million, the highest in at least 800,000 years.
   • Methane (CH4) and nitrous oxide (N2O) concentrations are also rising, significantly enhancing the greenhouse effect.
   • Increased greenhouse gases are directly linked to human activities, such as fossil fuel combustion and deforestation.

3. Arctic sea ice extent

   • Arctic sea ice extent has declined by about 40% since the late 1970s.
   • The summer minimum sea ice extent is decreasing at a rate of about 13% per decade.
   • Loss of sea ice affects global weather patterns and marine ecosystems.

4. Glacier mass balance

   • Glaciers worldwide are losing mass, with many retreating rapidly due to rising temperatures.
   • The annual mass loss of glaciers has accelerated, contributing to sea level rise.
   • Glacial meltwater is crucial for freshwater supplies in many regions.

5. Sea level rise

   • Global sea levels have risen by about 20 cm since 1880, primarily due to thermal expansion and melting ice.
   • Projections indicate a potential rise of 1 to 2 meters by 2100 if current trends continue.
   • Rising sea levels threaten coastal communities and ecosystems.

6. Ocean acidification

   • The ocean absorbs about 30% of CO2 emissions, leading to a decrease in pH levels.
   • Ocean acidity has increased by about 30% since the Industrial Revolution.
   • Acidification negatively impacts marine life, particularly organisms with calcium carbonate shells.

7. Extreme weather events frequency and intensity

   • The frequency and intensity of hurricanes, floods, and droughts have increased due to climate change.
   • Heatwaves are becoming more common and severe, impacting human health and agriculture.
   • Changes in weather patterns lead to unpredictable and extreme weather events.

8. Shifts in plant and animal ranges

   • Many species are migrating toward the poles or higher elevations in response to changing temperatures.
   • Altered habitats can lead to biodiversity loss and disrupt ecosystems.
   • Some species may face extinction if they cannot adapt or migrate.

9. Changes in growing seasons

   • Growing seasons are lengthening in many regions due to warmer temperatures.
   • Earlier springs and later autumns can affect crop yields and food security.
   • Changes in phenology can disrupt ecological relationships between species.

10. Permafrost thaw

    • Permafrost is thawing at an alarming rate, releasing stored greenhouse gases like methane.
    • Thawing permafrost can destabilize infrastructure and alter landscapes.
    • It contributes to further climate change, creating a feedback loop.

11. Coral reef bleaching

    • Increased sea temperatures lead to coral bleaching, where corals expel the algae they rely on for food.
    • Bleached corals are more susceptible to disease and mortality.
    • Coral reefs are vital for marine biodiversity and coastal protection.

12. Precipitation patterns

    • Changes in precipitation patterns are leading to wetter conditions in some areas and droughts in others.
    • Increased rainfall intensity can cause flooding and soil erosion.
    • Altered precipitation affects water supply and agricultural practices.

13. Drought frequency and severity

    • Droughts are becoming more frequent and severe due to changing climate patterns.
    • Prolonged droughts can lead to water shortages, crop failures, and increased wildfire risk.
    • Vulnerable regions, particularly in arid areas, face significant challenges.

14. Wildfires frequency and intensity

    • The frequency and intensity of wildfires have increased, particularly in forested regions.
    • Hotter, drier conditions contribute to longer wildfire seasons.
    • Wildfires can devastate ecosystems, property, and air quality.

15. Snow cover extent

    • Snow cover is decreasing in both duration and extent, particularly in the Northern Hemisphere.
    • Reduced snowpack affects water resources and ecosystems that depend on meltwater.
    • Changes in snow cover can influence local and global climate patterns.