A report by the C40 Cities Climate Leadership Group described consumption based emissions as having significantly more impact than production-based emissions within cities. The report estimates that 85% of the emissions associated with goods within a city is generated outside of that city.[10] Climate change adaptation and mitigation investments in cities will be important in reducing the impacts of some of the largest contributors of greenhouse gas emissions: for example, increased density allows for redistribution of land use for agriculture and reforestation, improving transportation efficiencies, and greening construction (largely due to cement's outsized role in climate change and improvements in sustainable construction practices and weatherization).In the most recent past, increasing urbanization has also been proposed as a phenomenon that has a reducing effect on the global rate of carbon emission primarily because with urbanization comes technical prowess which can help drive sustainability.[11] Lists of high impact climate change solutions tend to include city-focused solutions; for example, Project Drawdown recommends several major urban investments, including improved bicycle infrastructure,[12] building retrofitting,[13] district heating,[14] public transit,[15] and walkable cities as important solutions.[16]