Thaindian: If you believe human activities in the last century or so are responsible for climate change you may have to think again – a new research says early hunters could have upset the atmosphere`s methane balance. While extensive hunting in North America drove mammoths and other large mammals to extinction, it could have also disturbed the methane balance of the atmosphere, sparking off the global cool spell that followed. The large grazing animals would have been producing plentiful …