Two recent letters to the editor question the existence of human-caused global warming. One writer wonders how changes in earth’s temperature can be measured, given that we have night and day and different seasons. But couldn’t measurements be taken consistently, in different places at different times, and then averaged?
The other writer declared that CO2 is “not a pollutant that will cause global warming as it only makes up 0.04 percent of our atmosphere.” He points out that water vapor has a greater warming effect.
Neither of these writers gives any citations to research.
I urge these men (and others who are interested) to read the very clear and informative online article published by the Union of Concerned Scientists: “Why Does CO2 get Most of the Attention When There are so Many Other Heat-Trapping Gasses?” (https://www.ucsusa.org/global-warming/science-and-impacts/science/CO2-and-global-warming-faq.html).
This article explains why CO2 is more worrisome than water vapor — mainly because it stays in the atmosphere longer: 10 days for water vapor vs. up to 10,000 years for CO2. As the article points out, this means that “the heat-trapping emissions we release today from our cars and power plants are setting the climate our children and grandchildren will inherit.”