A new study ....suggests that Earth’s rain belts could be pushed northward as the Northern Hemisphere heats up faster than the Southern Hemisphere. That shift would happen in concert with the longstanding expectation for already wet areas to see more rain and for dry ones to become more arid.
The study, detailed Wednesday in the journal Science Advances, “adds to the large body of evidence that climate change is going to mess with the large-scale motions of air and water in the atmosphere. And this matters, because those patterns largely determine where it's rainy or arid, broadly speaking,” NASA climate scientist Kate Marvel, who wasn’t involved with the study, said in an email.
These changes in rain distribution could have implications for future water resources, particularly in areas where water supplies are already stressed, such as the western U.S. and parts of Africa.
...which regions are wet and dry are also determined by the locations of the Earth’s main rain belts. The positions of those rain belts, in turn, are tied to that of the so-called thermal equator (the ring around the planet’s middle where surface temperatures are highest). And the location of that equator is impacted by the balance of temperatures between the Northern and Southern hemispheres.
Because the Northern Hemisphere has more landmass, it is heating up faster than the Southern Hemisphere, and, as some climate models have suggested, this could push the thermal equator northward, and along with it those key rain belts.
Makes some sense, and intuitively, one of the most serious potential consequences of climate change.