Skip to main content
U.S. flag

An official website of the United States government

Publication Date
30 August 2018

Re-Examining Tropical Expansion



decades, implying a potential role of human activity. However, although theory and modelling suggest increasing GHG concentrations should widen the tropics, previous observational-based studies depict disparate rates of expansion, including many that are far higher than those simulated by climate models. Here, we review the rates and possible causes of observed and projected tropical widening. By accounting for methodological differences, the tropics are found to have widened about 0.5° of latitude per decade since 1979. However, it is too early to detect robust anthropogenically induced widening imprints due to large internal variability. Future work should target the seasonal and regional signatures of forced widening, as well as the associated dynamical mechanisms.

“Re-Examining Tropical Expansion”. 2018. Nature Climate Change 8: 768-775. doi:10.1038/s41558-018-0246-2.
Funding Program Area(s)