UN Climate Action Summit

The UN Climate Action Summit – Reducing Carbon Emissions

The 2019 UN Climate Action Summit was held at United Nations Headquarters in New York on 23 September 2019. The target of the summit was to advance climate action for reducing greenhouse gas emissions to prevent the mean global temperature from rising by more than 1.5 degrees above preindustrial level. Sixty countries were expected to “announce steps to reduce emissions and support populations most vulnerable to the climate crisis” including France, a number of other European countries, small island countries and India. To increase pressure on political and economic actors for achieving the aims of the summit, a Global Climate Strike was held around the world on 20 September with over 4 million people in attendance.

The Zero Carbon Buildings for All Initiative

The importance of zero carbon buildings (ZCB) to a sustainable future is clear. Buildings are responsible for nearly 30% of global energy-related greenhouse gas emissions. Fortunately, reducing energy demand in buildings also represents the most cost-effective way to tackle climate change and better buildings can add important co-benefits, like improving health and quality of life for residents and workers. The Zero Carbon Buildings for All Initiative, proposed for the 2019 UN Secretary-General’s Climate Action Summit in New York, unites leaders across sectors in a strong international coalition to decarbonize the building sector and meet climate goals. Zero Carbon Buildings for All’s core components include securing commitments from two audiences:

  • National and local leaders, to develop and implement policies to drive decarbonization of all new buildings by 2030 and all existing buildings by 2050
  • Financial and industry partners, to provide expert input and commit $1 trillion of market action by 2030
  • These commitments join and complement the corporate real estate and sub-national commitments galvanized by partner World Green Building Council’s Net Zero Carbon Buildings Commitment.

What Are Zero Carbon Buildings (ZCBs)?

ZCBs are buildings with a net zero amount of carbon emissions associated with their annual energy demand. ZCBs achieve this by:

  • Implementing high levels of energy efficiency
  • Meeting energy needs with on- or off-site renewable energysourcing

In some cases, as a last resort, buildings can also partly achieve net zero emissions through carbon offsets, which often come in the form of renewable energy investments elsewhere. Offsets, however, are only recommended for cases in which a 100% renewable energy supply is not feasible. While in the past ZCBs have been seen as a target only wealthy countries could reach, there are policy pathways today to reach zero carbon buildings regardless of location or development status.

How Do We Achieve ZCBs?

We have the technology to achieve ZCBs in nearly every context; what national and local leaders need are policy pathways and financing solutions. There are multiple ways to achieve ZCBs through combinations of energy efficiency, renewable energy and carbon offsets, in the following order of priority:

The more carbon avoided through efficiency, the better. Energy efficiency is generally the cheapest approach, and remaining energy needs can then be met with greener energy supply.

In addition to the set of principles shown above, municipal, national and state governments have different roles and degrees of influence in achieving ZCB pathways. These guiding principles lay the groundwork for a menu of pathways to arrive at net zero carbon for individual buildings, districts and building portfolios – turning carbon neutrality from an aspiration into a target well within reach.