To the Editor:

The episode of cold weather in Ohio and the United States in 1816 through 1818, related nicely in context by historian Ed Lentz in the Jan. 11 issue, was not just a natural fluctuation in the weather, but a massive climate event affecting the entire globe.

I have a small teacup produced and sold in Germany shortly thereafter, commemorating it.

The cup carries a rhymed verse (in German): "After many a hardship of war (the Napoleonic wars) we should have to live to see this horribly expensive year, such as scarcely ever occurred; Heaven however wants only, through these dire things, to make you rich in experience, not always in good fortune." The saucer lists outrageous 1817 prices for over a dozen basic foodstuffs.

That "year without a summer" was caused by the enormous explosion of a volcano in Indonesia, Mount Tambora. The connection was not recognized for many decades. Like a number of recorded extremely large volcanic events, it led to political unrest far and wide. Correlations are clear between climate disasters and political upheaval documented since as far back as the sixth century in China. The explosion of Krakatoa in 1883 led to one of the other cold winters and poor harvests cited by Lentz.

This 100-year anniversary is an opportunity to point out that major disturbances of climate, natural or manmade, will not just change our heating or air-conditioning bills, but threaten our agriculture and the stability of political structures around the globe.

Humanity's effects on the atmosphere already compete with the impact of many a volcano. No one could stop Tambora or Krakatoa, but we can probably stop a looming manmade climate disaster, the effects of which would last for centuries.

Brenda Winnewisser