A guaranteed universal basic income is completely possible! 
If all nations were to act as a unified global society, we could fund a universal basic income and eradicate world poverty by: using existing welfare spending, dramatically increasing taxes on the income and wealth of billionaires & large corporations, taxing mega-churches, and leveraging sovereign wealth funds. Currently there is over $13.7 trillion held in sovereign investments worldwide! These deep pockets of wealth could be redirected to provide a basic income for all people. 
By combining fair tax laws with efficient use of public wealth, a global public safety net is not only economically possible but also a powerful tool to eliminate extreme poverty and promote global stability.