Utilities and Energy

The global fight against climate change needs better city data

Today, in New York City, the world’s leaders will sign the landmark climate change accord they agreed to last December in Paris. At the same time, New York City will release its annual progress report.

By Rohit T. Aggarwala

Green roof with NYC skyline in the background

Today, in New York City, the world's leaders will sign the landmark climate change accord they agreed to last December in Paris. At the same time, New York City will release its annual progress report

The two acts are intimately related. They remind us not just how important good data is to good policy, but how difficult it can still be to get actionable data at the city level.

It's been clear for a long time that cities are critical to the global fight against climate change, both because they account for a large portion of global emissions and because they are where some of the biggest, fastest, and easiest gains can be made . We also know that dense urban living is the only sustainable way for the world's growing population to achieve a high standard of living and a sustainable one at the same time.

What hasn't been clear is exactly what the emissions of the world's cities are, and whether they're really moving forward or backward. Nine years ago, when the Bloomberg administration created PlaNYC and New York City's first GHG inventory, only a few cities around the world had done full inventories.

This lack of data led to two problems in most urban sustainability action plans. One was that cities tended to focus on the items they could calculate, such as greening municipal buildings, rather than the far bigger impacts they could have by changing citywide policy.

The other was that it was difficult (or impossible) to identify actions that could and should be taken based on data about how important each action was. Basically, cities were flying blind.

As more and more cities undertook climate action, many cities did their own greenhouse gas inventories. Still, almost none did them every year. And they used a wide variety of protocols for how to calculate those emissions.

This lack of standardization created its own problem: while the world's mayors increasingly talked about how their efforts were critical to the climate change plans of national governments, their actual contributions were difficult to compare and assess.

So difficult, in fact, that the Intergovernmental Panel on Climate Change noted the problem in 2014: "Thousands of cities are undertaking climate action plans, but their aggregate impact on urban emissions is uncertain" because of a lack of standardized, rigorous reporting.

This year marks a big milestone in addressing the IPCC's concern. First, this marks the first year that many cities are adopting the new Global Protocol for Community-Scale Greenhouse Gas Emissions (GPC). Undertaken by the C40 Cities Climate Leadership Group, ICLEI, the World Bank, and the World Resources Institute, this new standard will ensure that cities' carbon inventories are directly comparable, enabling reliable comparisons, rankings, and intercity learnings for the first time.

Second, this year the first requirements of the global Compact of Mayors take effect. Spearheaded by my former boss, Michael R. Bloomberg, in his role as the UN's Special Envoy for Cities and Climate Change, this effort --- which 488 cities from every continent are now signed onto --- requires annual GHG reporting, submitted into a single source. (The Compact of Mayors requires the use of the GPC.)

This isn't just a boring accounting exercise. Taken together, these two initiatives will significantly accelerate the contributions cities make to the world's fight against climate change.

The first impact will be at the local level. By requiring cities to inventory their emissions every year and report them in a standard way, mayors and others will be forced to ask themselves --- every year --- whether they are really making progress towards emissions reductions. This will ensure that meaningless initiatives that may be popular or easy but don't generate results quickly get revealed.

It'll also ensure that city officials who are serious about progress on climate know where to look for the impacts they seek. This insight will make city policies smarter and more effective.

Annual reporting will also force city officials to understand how complex the challenge is. When I was in the Bloomberg administration, we had to develop a complex methodology to factor out all the statistical noise in the annual changes in New York's total emissions. Every year, the weather changes, the number of jobs changes, the population changes; all of these factors change total emissions but don't tell you whether long-term progress is being made. For example, over the last two years, New York has suffered really cold winters that have required greater heating and thus cancelled out improvements in energy efficiency and other areas. Similarly, it's possible that in other cities, a slowing economy could reduce overall emissions, but this does not indicate actual progress towards sustainable prosperity.

The GPC and the Compact of Mayors will also ensure that the actions of the world's cities receive the support, attention, and scrutiny they deserve. By making data from the world's cities centrally accessible and easily comparable, these efforts will make it possible for the UN Framework Convention on Climate Change to rely on urban contributions. National governments will be able to delegate some of their reduction commitments to city leaders, and in turn cities will be able to make the case that they need the powers and the resources from national governments to realize their promise.

Unsurprisingly, better data will lead to better outcomes.

There's still a lot left to do. As it is Earth Day, people who care about the intersection of technology and cities will rightly be thinking about the potential for self-driving cars, smarter energy systems, better transit data, and other tech innovations to reduce urban GHG emissions.

But I hope they're also thinking about how they can help cities understand their carbon emissions better.

Doing a GHG inventory is still a highly manual, labor-intensive process. At best, inventories are available on an annual basis, usually with a lag of more than a year. It's hard to drill down to get data on how a given neighborhood is doing. And even the most robust inventories still use far too many estimates.

Ideally, we'd have a seamless, global database of emissions that would allow anyone to create a custom inventory --- for their block, their building, their city, or their county --- and monitor it in real time. Just as Fitbits and iPhones got people focused on how many steps they took each day, a truly advanced GHG calculator would change the way cities think about their emissions, and reduce the frictions associated with doing so.

This tool is not here yet, but it would be a fitting contribution for April 22 from the world of urban technology, and a task worthy of the resources devoted to it. Because, as Mayor Bloomberg always challenged me, "if you can't measure it, you can't manage it." And that is a challenge that urban tech should be able to take in its stride.

Happy Earth Day.