In the past few years, the scientific community has reached a consensus that climate change, especially global warming, is a real phenomenon. Furthermore, there is a general agreement that human activities, especially the generation of carbon dioxide, methane, and other greenhouse gases, are probably the main drivers of these changes. Even though the long term effects of climatic changes are unknown, they are reasonably thought to include melting of the polar ice caps, a rise in ocean levels, increased hurricane and typhoon activity, and changes in seasonal weather patterns that will affect food crop production. As some of these effects have already begun, many parties believe that global solutions must be reached in order to limit the harmful effects of human activities before said effects reach catastrophic and/or irreversible levels.
Because industrialized urban centers produce a large proportion of the world's greenhouse gases, it is imperative to find solutions that limit their total production and proportionate share of these emissions. With this problem in mind, New York City, in its plaNYC 2030, set a target of a 30% reduction in emissions by the year 2030. Some parties, however, believe that even more drastic steps are required. The New York Urban Green Council, being one, put together an ambitious plan targeting an even greater reduction in the city's carbon footprint. Known colloquially as "90 by 50", the plan aims for a 90% reduction in New York's emission of carbon dioxide by the year 2050*. And due to the fact that the building sector generates 75% of the emissions in NYC, the plan necessarily devoted a large amount of attention to that sector.
In order to generate emissions reductions in the sector, the plan advocates measures such as the usage of thermal barriers, triple glazed windows, photovoltaic cells, and improved HVAC systems. There’s nothing particularly new or next generation about these technologies; they exist today. And when implemented correctly, with Passive House certified buildings being a prime example, they have been shown to work. Buildings constructed or retrofitted to the Passive House standard will typically demonstrate a roughly 80% improvement in energy efficiency (as measured by the HERS Index) when compared to the average new house constructed in the US today. If a substantial proportion of the city’s building were to be constructed or retrofitted with the aforementioned energy efficiency measures and techniques, à la Passive House, we would be well on our way to approaching the goal of “90 by 50”. But not only that; the goal could be reached much sooner if ways can be found to promote, in the near term, the adoption and implementation of these energy-efficient measures and techniques.
*Footnote: 90% of emissions currently tracked by the city. The city does not track certain emissions such as those from building materials, food, and airplanes.