Global climate change

Tropical climate zones are expanding as predicted

By Brett Anderson, AccuWeather senior meteorologist
9/19/2018, 1:12:16 PM

The tropical climate zone has been widening at an average rate of about 0.2 degrees latitude or 17 miles per decade in both the Northern and Southern hemispheres.

This widening appears to match up quite well with what climate models had predicted, according to a new study from Indiana University.

Tropical (darker blue) and desert (red) are some of the climate zones shown on the map below.

"Climate change should continue to expand the tropics over the next several decades," said study co-author Paul Staten from Indiana University. "But the expansion may not continue at the rapid rate we've seen; at times it may even temporarily contract."

Widening of the tropics can result in major shifts in climate for some regions just outside the tropical climate belt. Hot, dry deserts tend to lie along the edges of these tropical climate zones, and these changes can lead to an expansion of desertlike climate zones.

The study lists five primary factors that may influence the widening of the tropics......

1. Increasing greenhouse gas emissions, which also lead to warming.

2. High atmospheric ozone loss.

3. Aerosols from volcanic eruptions.

4. Increasing air pollution.

5. Natural variation, such as ENSO. (El Nino Southern Oscillation).

The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or


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Global climate change