"Ancient Mayans created their own 'climate change' 1,800 years ago and 'caused the droughts that wiped them out' "

More Mayans.
From the Daily Mail, October 8:

Ancient Mayan farmers may have triggered their own version of climate change and contributed to their own demise, according to researchers.

Scientists have found evidence in Belize that the Central American people used to dig canals and wetlands and to have regular burns while farming their land.

The latest discoveries suggest the Mayans, between 1,800 and 1,000 years ago, had a bigger impact on their environment than previously thought.

And they may even have worsened conditions to such an extent it contributed to the droughts thought to have wiped out the civilisation.

 

Researchers suggest that the Mayans expanded a natural wetland in Belize to be more than five times as large as was previously thought (pictured: a computer-generated image of how the wetlands may have looked from above). Plants in the wetland, and the process of burning down trees in order to make more room for waterways, pumped greenhouse gases into the atmosphere, the University of Texas researchers said 
 

Researchers from the University of Texas have suggested their theory based on aerial scans and imaging of the legacy Mayan farmland left underground. 

They discovered that a wetland known as the Birds of Paradise wetland, in northwestern Belize, was five times as big as had been believed.

And they also found another similar complex which was even larger.

The wetlands had irrigation ditches and canals built into them and sometimes forest was destroyed to make way for them.
These processes were made more extreme as the Mayans tried to adapt to a changing climate – mainly rising sea levels – about 1,800 years ago.

Although they were useful in controlling water and preserving it to use during droughts, passages in the wetlands contained plants which produced high levels of methane, a greenhouse gas.

And the farmers also pumped carbon dioxide into the air by burning vegetation to clear space for their canals.

'We now are beginning to understand the full human imprint [on] tropical forests,' said Dr Tim Beach, the lead author of the study

'These large and complex wetland networks may have changed climate long before industrialization, and... even these small changes may have warmed the planet....MORE

Earlier:
More On the Myth Of Pristine Primordial Pre-Columbian Americas

 "The Myth of the Pristine Amazon Rainforest"