As urbanization, industrialization, and consumption grow, environmental pressures multiply. While technology is only one option for addressing these issues, it can be a powerful one. Overall, analysis finds that deploying a range of applications to the best reasonable extent could cut emissions by 10–15%, lower water consumption by 20–30%, and reduce the volume of solid waste per capita by 10–20%.
Greenhouse gas emissions
In a city where structures are the major source of emissions, building automation systems can lower emissions by just under 3% if adopted in most commercial buildings and by an additional 3% if adopted in most homes. Another application with significant potential is dynamic electricity pricing, which allows utilities to charge more when demand peaks. By reducing consumption and shifting the load to off-peak periods, it reduces the power sector’s use of backup “peaker plants” that produce more emissions. E-hailing and demand-based microtransit could significantly reduce emissions if fuel-efficient fleets offset more polluting alternatives. Intelligent traffic signals, congestion pricing, and other mobility applications also cut emissions from traffic.
Some of the energy-saving and mobility applications described above could improve air quality as a secondary benefit. To tackle this issue more directly, cities can install air quality sensors. They do not automatically address the causes of pollution, but they can identify the sources and provide the basis for further action. Beijing reduced deadly airborne pollutants by roughly 20% in less than a year by closely tracking the sources of pollution and regulating traffic and construction accordingly. Sharing realtime air quality information with the public via smartphone apps enables individuals to take protective measures, potentially reducing negative health effects by 3–15%, depending on current pollution levels.
Water consumption tracking, which pairs advanced metering with digital feedback messages, can nudge people toward conservation. It could reduce consumption by 15% in a higher-income city where residential water usage is high, although its effectiveness depends on whether it is paired with a pricing strategy. In many parts of the developing world, the biggest source of water waste is leakage from pipes. Deploying sensors and analytics can cut those losses by up to 25%.
Solid waste reduction
As low-tech recycling programs reach the limits of what they can do, technology could further reduce the volume of unrecycled solid waste. Digital tracking and payment for waste disposal, for instance, charges users for exactly for the amount and type of trash they throw away. But this type of application should be considered alongside other policy initiatives, particularly in developing economies where household budgets are tight and a great deal of informal recycling already takes place.