Waste-to-energy, which is a popular alternative to landfilling particularly in Europe, has been argued to not be as healthy or efficient as recycling. However, some zero-waste activists believe that incineration and recycling can co-exist to all together minimize waste that is landfilled. Others argue that incineration diverts products away from recycling. Cities are facing many waste management issues in relation to incinerators including long-term contracts and the need to import waste in order to maximize productivity.