Tropical zone expanding due to climate change

Climate change is rapidly expanding the size of the world’s tropical zone, threatening to bring disease and drought to heavily populated areas, an Australian study has found.

Researchers at James Cook University concluded the tropics had widened by up to 500 kilometres (310 miles) in the past 25 years after examining 70 peer-reviewed scientific articles. They looked at findings from long-term satellite measurements, weather balloon data, climate models and sea temperature studies to determine how global warming was impacting on the tropical zone. The findings showed it now extended well beyond the traditional definition of the tropics, the equatorial band circling the Earth between the Tropic of Cancer and the Tropic of Capricorn. Professor Steve Turton said that meant the subtropical arid zone which borders the tropics was being pushed into temperate areas, with potentially devastating consequences. “Such areas include heavily-populated regions of southern Australia, southern Africa, the southern Europe-Mediterranean-Middle East region, the south-western United States, northern Mexico, and southern South America,” he said. “All of (them) are predicted to experience severe drying. “If the dry subtropics expand into these regions, the consequences could be devastating for water resources, natural ecosystems and agriculture, with potentially cascading environmental, social and health implications.” … “There is also evidence that many Australian animal and plant species are moving south in an attempt to track their preferred climatic conditions. Some won’t make it.” …

Tropical zone expanding due to climate change: study