The world’s largest cities have a significant role to play in global climate change efforts and they’d best get moving, the C40 megacities network said in a report Thursday. “The overriding and deeply significant finding of the work is that the next 4 years will determine whether or not the world’s megacities can deliver their part of the ambition of the Paris Agreement. Without action by cities the Paris Agreement can not realistically be delivered,” the report says.
According to the report, if cities are to do their part to limit global temperature rise to 1.5 degrees Celsius, as called for in the Paris Agreement on climate change, the 86 cities affiliated with the C40 can boost their carbon dioxide emissions by only 5 percent before peaking. Following the emissions peak, “average per capita emissions across C40 cities need to drop from over 5 tCO2e [tonnes of carbon dioxide equivalent] per capita today to around 2.9 tCO2e per capita by 2030,” the report says.
The report finds that of the 387 gigatonnes of carbon dioxide equivalent that the world can use before 2100 and still keep temperature rise below 1.5 degrees, C40 cities should only produce 22 GtCO2e, about 6 percent of the total budget. This total is based on a number of factors accounting for issues of equality, responsibility, and capacity. “This budget is calculated by assuming cities’ per capita emissions (and those of the rest of the world) converge linearly to a common value, then everyone declines to zero at a common rate depending on the remaining budget,” the report explains.