The Need for Action on Climate Change Is Urgent!

by Les Grady, Environmental Engineer, retired

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

• Evidence from diverse sources confirms climate change.
  • The 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.
  • Weather is getting more extreme.
  • Ecosystems are changing more rapidly.
• Evidence for the role of CO₂ as the main cause of climate change is unequivocal.
  • 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 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).
  • Earth’s temperature is directly proportional to the amount of CO₂ in the atmosphere.
  • 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.
  • Satellite measurements of top of atmosphere radiation confirm that GHGs are responsible for Earth’s observed warming.

We must stop releasing CO₂ to stabilize Earth’s climate.