YOU DON’T SAY: Reflecting sunlight to cool the planet will cause other global changes.

Now scientists at MIT have found that solar geoengineering would significantly change extratropical storm tracks — the zones in the middle and high latitudes where storms form year-round and are steered by the jet stream across the oceans and land. Extratropical storm tracks give rise to extratropical cyclones, and not their tropical cousins, hurricanes. The strength of extratropical storm tracks determines the severity and frequency of storms such as nor’easters in the United States.

The team considered an idealized scenario in which solar radiation was reflected enough to offset the warming that would occur if carbon dioxide were to quadruple in concentration. In a number of global climate models under this scenario, the strength of storm tracks in both the northern and southern hemispheres weakened significantly in response.

Weakened storm tracks would mean less powerful winter storms, but the team cautions that weaker storm tracks also lead to stagnant conditions, particularly in summer, and less wind to clear away air pollution. Changes in winds could also affect the circulation of ocean waters and, in turn, the stability of ice sheets.

“About half the world’s population lives in the extratropical regions where storm tracks dominate weather,” says Charles Gertler, a graduate student in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). “Our results show that solar geoengineering will not simply reverse climate change. Instead, it has the potential itself to induce novel changes in climate.”

It’s only a matter of time before some over-eager world-saving progressive suggests Congress pass a law against unintended consquences.