I challenge “Not so hot” of July 21. Here are the demonstrable facts.

Evaporation from the equatorial region moves to the poles via air currents then precipitates as snow. Water molecules are not identical. Water has a stable portion of deuterium and tritium, heavy isotopes of hydrogen. More energy (temperature) is necessary to evaporate heavy water. The ice fields of both poles provide accurate data about global temperature by measuring the proportion of heavy water. This are rich data which provide accurate information dating back for 800,000 years. Soil temperature readings from mines and wells below the frost line confirm the ice field data. Likewise, the ice fields contain trapped atmospheric gases like carbon dioxide and methane. The direct link between greenhouse gases and global temperature is indisputable.

Ice fields and glaciers are all fresh water, and different density than sea water. As the ice fields melt, the denser water sinks in the adjacent ocean changing the global water currents, and consequently the air currents. Weather satellites have detected and continually measure phenomena such as El Nino and La Nina in the equatorial Pacific. Events such as and unstable polar vortex resulting in extreme low temperatures events in lower latitudes. Extreme low temperature events in the lower latitude is the process of global warming. It is like putting an ice cube in hot coffee. The cooler coffee is the result of a melting ice cube.

The atmosphere is 80% nitrogen. Powerful sun rays knock a proton from some nitrogen making it carbon but with an extra neutron — carbon 13 which decays into normal carbon 12 over a period of 60,000 years. All living things consuming atmospheric carbon carry carbon 13. In dead things, the carbon 13 begins to decay. Carbon dating is an accurate measure of time of death. The plants and animals alive 66 million years ago when the meteor caused mass extinction are the source of today’s fossil fuels. This biomass-fossil fuel material has completed its carbon 13 decay to carbon 12. The fuel we burn has no carbon 13. The atmosphere rise in carbon dioxide and methane have smaller portions of carbon 13 thus proving the increased greenhouse gases are the result of human activity burning fossil fuel.

Ice is very brittle stuff. A little tension or shear stress and it breaks easily. A large portion, bigger than Rhode Island, broke away from the Ronne Ice Shelf in Antarctica in May. Just a small increase in sea level would exert tremendous buoyant forces causing the ice to crack and shift. Events in Florida, the land of sink holes and collapsing condominiums, will ultimately relate back to higher water tables — rising sea levels — which dissolve the supporting geological foundation. Although Miami has plenty of time to build sea walls, and New York is not in imminent danger of flooding the subway system with the Atlantic Ocean, rising sea level is happening and producing obvious effects.

Ice and snow reflect the sun’s rays. If you go skiing remember to put sunscreen under your chin or you risk a sun burn. Water, on the other hand, absorbs more of the sun’s rays. As the Arctic melted the absorption of the water causes the ice to melt at a faster and faster rate. The northern tundra melts and releases huge quantities of methane from rotting vegetation, again accelerating the process. At some point, not far away, the process becomes irreversible. Beyond that point changes to our Earth will become dramatic. We will have difficulty adapting. Earth will remain, but people will not.

On June 28, I measured 124 degrees on my back deck. It was in the sun; however, the hemlock tree in the front yard, which cannot hide from the sun, dropped 85% of its needles. It, and many other conifers, quite likely will not survive that event. The cherry crop took a beating with cherries shriveling on the tree. Soil moisture content has dropped dramatically. No amount of no-till farming will compensate for the drought. Agriculture is a key element of our community. I think it is plain to see it is in peril. The Dalles will not be much with only a Google server farm.

Terry Armentrout worked as operation manager at The Dalles Dam and is now retired.