Atmosphere full of greenhouse gases

To the editor:

The first scientists to reason there must be a greenhouse effect was Jean Baptiste Joseph Fourier in 1820. He had the idea that incoming visible and ultraviolet light could easily pass through the atmosphere, but that ultraviolet light had a hard time passing back through it. He reasoned this created warming effect like an insulating blanket.

The next scientists to take up this idea was John Tyndall in 1859. Tyndall accurately measured trace infrared heat blocking gases C02, CH4, N20. He suggested that changes in the concentration of these gases could bring about climate change.

The next scientists to advance climate science was Svante Arrhenius in 1896. He made the first calculations of human-induced climate change. He calculated that doubling atmospheric carbon dioxide would increase average surface temperatures 5 to 6 degrees Celsius. He did not anticipate the tremendous amount of greenhouse gas pollution that humans were capable of. He understood that temperatures follow increased greenhouse gases in the atmosphere. C02 was about 275 ppm in 1896. CH4 was about 750 ppb in 1896. Today, CO2 is around 403 ppm at Mauna Loa, Hawaii, and about 420 ppm in the Arctic. Methane is about 1860 ppb at Mauna Loa and about 2000 ppb and above in the Arctic. Climate Scientists Dr. James Hansen states that C02 above 350 ppm and CH4 above 1250 ppb is not sustainable. Ther are already enough greenhouse gases in the atmosphere to make life unsustainable.

Harold Hensel

Cedar Rapids