The Need for Action on Climate Change Is Urgent!

by Les Grady, Environmental Engineer, retired

earth as hourglass
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Driven mainly by carbon dioxide (CO2) emissions, Earth’s climate is changing.

  • Evidence from diverse sources confirms climate change.
    • Atmospheric temperature reconstructions show that current warming is unprecedented within the span of human civilization.
    • Oceans are warming.
    • Glaciers are melting.
    • Sea level is rising.
    • The Arctic ice cap is shrinking, the ice is thinning, and its nature is changing.
    • Although East Antarctic ice is increasing, West Antarctic ice is decreasing much faster.
    • Weather is getting more extreme.
    • Ecosystems are changing more rapidly.
  • Evidence for the role of CO2 as the main cause of climate change is very strong.
    • Earth’s temperature is stabilized and regulated by the greenhouse effect.
    • The major greenhouse gases (GHGs) are CO2 and water vapor.
    • Water vapor is responsible for 50% of the greenhouse effect, but its life in the atmosphere is short because it condenses as rain and snow. CO2 is directly responsible for 20% of the greenhouse effect, but its indirect effect is much larger. Because it does not condense, it stays in the atmosphere for a very long time, thereby influencing the water vapor content and regulating Earth’s temperature.  It is Earth’s thermostat.
    • The level of CO2 in the atmosphere is increasing because of the burning of fossil fuels (coal, oil, and natural gas).
    • Satellites show a reduction in outgoing (i.e., cooling) radiation leaving Earth at the wave-lengths associated with CO2 and other GHGs.
    • Land-based sensors show an increase in incoming (i.e., warming) radiation from CO2 and other GHGs consistent with their increased concentration in the atmosphere.

We must release less ­­each year to stabilize Earth’s climate.