Image credits: Dave/Flickr Creative Commons/CC BY 2.0; Acropora at English Wikipedia; Martin Haas/Shutterstock.

There has been much talk globally about limiting global warming to 1.5°C instead of 2°C. This distinction might seem minor, so what difference would half a degree really make?

According to new research from the European Geosciences Union, quite a bit. As NASA says:

“[The study] found that the jump from 1.5 to 2 degrees—a third more of an increase—raises the impact by about that same fraction, very roughly, on most of the phenomena the study covered. Heat waves would last around a third longer, rain storms would be about a third more intense, the increase in sea level would be approximately that much higher and the percentage of tropical coral reefs at risk of severe degradation would be roughly that much greater.”

And when it comes to coral reefs, fresh water availability, and agriculture, that half a degree would mean a much more significant difference:

“At 1.5 C, the study found that tropical coral reefs stand a chance of adapting and reversing a portion of their die-off in the last half of the century. But at 2 C, the chance of recovery vanishes. Tropical corals are virtually wiped out by the year 2100.

“With a 1.5 C rise in temperature, the Mediterranean area is forecast to have about 9 percent less fresh water available. At 2 C, that water deficit nearly doubles. So does the decrease in wheat and maize harvest in the tropics.

“On a global scale, production of wheat and soy is forecast to increase with a 1.5 C temperature rise, partly because warming is favorable for farming in higher latitudes and partly because the added carbon dioxide in the atmosphere, which is largely responsible for the temperature increase, is thought to have a fertilization effect. But at 2 C, that advantage plummets by 700 percent for soy and disappears entirely for wheat.”

And this analysis doesn’t even mention the further effects of such changes, such as increased migration of people and animals due to homelands and habitats disappearing.

Read more, including NASA’s analysis of the findings, here.