Two points raised in Brian Bauer’s letter to the editor (Nov. 2) on climate change research deserve scrutiny. While he is correct in stating that all forms of energy production are associated with adverse outcomes (and the consequent “vocal opposition”), there are additional questions that should be asked concerning the extraction, transportation, use and health effects of each energy source that might distinguish value between various energy sources. For example, who bears the bur-den of an energy source extraction, how broad and long-lasting is the damage of a particular energy source, what are the costs of the energy infrastructure that support each source, etc.
Addressing such issues can help determine real costs of different energy sources.
The other point raised in this letter concerns the fact that Earth’s climate has always changed without man’s input. Orbital variations, volcanoes and solar variability all contribute to climate change. Science does not dispute these facts. However, recent global warming cannot be explained by these sources. Orbital variations play out over thousands of years if not more. The number of volcanic eruptions is not consistent with large increases in recent warming in the last two centuries. Solar variability occurs over an 11-year cycle and the warming being seen today does not mirror this cycle. The alarming aspect of the current climate change is the speed at which it is occurring. The only known factor that is consistent with this trajectory is the addition of greenhouse gases introduced into the atmosphere by mankind’s activities (burning fossil fuels, landscape changes, population growth, etc.).
One might also consider that the amount of greenhouse gases in the atmosphere today are not higher than ever before. But, those higher levels occurred before humans were on this planet. This is a sobering thought.
Susan T. Zimny
Bridport