A letter, “Climate Change,” PDN, Oct 20, claimed that scientific research supporting a less extreme view of climate change is conveniently ignored in favor of extremist warnings.
Being a retired NASA glaciologist and climate scientist, I reviewed the scientific paper referred to by the writer and note three errors.
The referenced paper, by Medford, documents variations in the extent of the Renland Ice Cap, not the 1,200-times larger Greenland Ice Sheet as implied in the letter.
Smaller ice caps are strongly affected by local meteorological conditions thus exhibiting much larger variability than large continental-scale ice sheets.
Global climate research is based on the assimilation of a vast number of detailed local studies like Medford’s; no single research result is spatially broad enough to overturn the global result.
Because Medford’s recent paper is based on his master’s thesis, I contacted his thesis advisor and co-author, Dr. Brenda Hall, who assured me this research doesn’t undermine the overwhelming consensus of the scientific community that the Earth is experiencing a period of accelerating warmth driven largely by human use of fossil fuels.
There is no disagreement from climate scientists that large, widespread climate variations driven by natural, i.e., non-human, forces have occurred.
However, this does not guarantee that climate change can only be the result of natural forces.
There is overwhelming evidence that human activity has released excessive amounts of greenhouse gases, resulting in higher globally averaged temperatures that are now causing more frequent extreme weather events.
The climate crisis is real.