World Meteorological Day: A Hotter, Drier, Wetter World of Weather

Today is World Meteorological Day, held each year on the date (March 23, 1950) when the treaty creating the World Meteorological Organization went into force. The theme of this year’s World Meteorological Day is a timely one: “Hotter, Drier, Wetter—Face the Future.” Dozens of billion-dollar weather disasters plagued our planet in 2015—many of them involving droughts and floods—and inflicted a total $123 billion in damage (see Figure 1, below). That total came in below the 15-year average of $175 billion. However, the pain was widely distributed in the form of 29 separate billion-dollar disasters, the fourth largest number since accounting began in 1990, according to insurance broker Aon Benfield.

While the economic toll from heat waves occurs largely in the form of agricultural losses related to drought, heat waves also pose a direct risk to human health. A severe pre-monsoonal heat wave took an estimated 2500 lives in India during May 2015, making it the nation’s second deadliest heat wave on record and the fifth deadliest in world records compiled by EM-DAT.

Human-produced climate change is already hiking the odds of the three weather trends highlighted by the WMO. Heat extremes are on the rise both nationally (see photos below) and globally. In many parts of the world, the heaviest precipitation events (such as the top 1% of one-day totals) are becoming even heavier. And when drought strikes, the impact is exacerbated by a warmer atmosphere, which allows more moisture to escape from parched soils and drying lakes; in turn, the ever-drier ground allows temperatures to soar even further. This year’s World Meteorological Day theme reminds us, as does a recent report from the National Academies, that the climate of our future is related to the weather events that we deal with every day.

Bob Henson







Figure 1. (below) The 29 billion-dollar global weather disasters, adjusted for inflation, as compiled by insurance broker Aon Benfield in their Annual Global Climate and Catastrophe Reports. There are several more U.S. severe-weather events in the list than are shown in the accompanying map, due to space constraints: Image credit: Lauren Moyer/WU.