Original sentence: A small minority of qualified scientists contest the view that humanity's actions have played a significant role in increasing recent temperatures.Uncertainties do exist regarding how much climate change should be expected in the future, and a hotly contested political and public debate exists over what actions, if any, should be taken in light of global warming
Edited sentence: However, qualified scientists contest the view that humanity's actions have played a significant role in increasing recent temperatures.There is a hotly contested political and public debate exists over what actions, if any, should be taken in light of global warming and economic costs associated with such actions.Uncertainties do exist regarding how much climate change should be expected in the future, as well as how much natural cycles and solar variability play a role