Human impacts on the climate preceded the dawn of the petroleum age

Prior posts, occasionally with tongue planted firmly in cheek, have noted that human impact on carbon loading in the atmosphere goes back to well before the industrial era. A recent assessment has calculated that over the eight millennia before 1850, clearing land (for both hunting and for farming...

Early European explorers of North America may have indirectly triggered the Little Ice Age by exposing the local population to new diseases

By the end of the 15th century, between 40 and 80 million people are thought to have been living in the Americas. Many of them burned trees to make room for crops, leaving behind charcoal deposits that have been found in the soils of Mexico, Nicaragua, and other countries. About 500 years ago, this charcoal...

Could the Amazon Become a Greenhouse Gas (GHG) Emitter Rather Than a Sink?

The Amazon has long been conceived of as a CO2 sink because of its mass of vegetation. Researchers are now concerned that drought and deforestation may make it a net emitter. Because of regular measurements of about 100,000 trees, researchers estimate that the Amazon was absorbing about 1.5 billion...