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.