
© Wikipedia / Mats Halldin
The annual see-saw of the tropical rain belt.
The tropical rain belt, also known as the Intertropical Convergence Zone (ITCZ), is in a state of constant migration. It continuously changes position in response to the seasons and follows the sun's zenith, with a slight delay. This in turn determines the wet and dry periods in the tropics and subtropics over the course of the year. The tropical rain belt therefore effectively controls the climate in most of the tropical and subtropical regions, such as the monsoon season in Southeast Asia and Central America.
An international team of researchers led by Franziska Lechleitner from the Geological Institute at ETH Zurich has proven for the first time that the migration of the tropical rain belt is quite sensitive to even small changes in global temperatures. The team's findings have been published in the journal
Scientific Reports, where they present the most comprehensive reconstruction of rainfall patterns within the Intertropical Convergence Zone for the past 2000 years.
Lower temperatures worldwide
In the past, scientists have only studied the migration of the tropical rain belt over very long timespans, such as glacial and interglacial cycles over tens of thousands of years, with correspondingly sizeable
temperature differences of several degrees. "So far, however, scientists have not investigated the past two millennia on a global scale, when temperature changes have been far less pronounced," explains the climate geologist.
The ETH researcher and her colleagues have now managed to demonstrate how the
tropical weather system shifted a good way south between 1450 and 1850, a period known as the Little Ice Age. "This migration is linked to the lower global temperatures during this time," explains Lechleitner.
The latest climate reconstructions show that the average temperatures during this period were around 0.4 degrees Celsius lower than before and after the Little Ice Age. The migration of the tropical rain belt also caused substantial changes in the tropical and subtropical climate during this time, affecting the areas of drought and
heavy rainfall.
Comment: It makes so much sense to work with and learn from nature rather than seeking to exploit our natural resources because of the greed of psychopaths in power. We can see in these examples, human creativity and innovation at work and how technology, instead of being used to oppress people and advance warfare, can be used for the betterment of humanity.
For more on some of the designs, in particular the Dewpoint water collector, see this video.
And this is what Wanda Lewis, the designer of the leaf-inspired bridge, had to say about her ambitious project: