Since 2010, United Nations Environment (UNEP) has produced annual Emissions Gap Reports based on requests by countries for an independent scientific assessment of how actions and pledges by countries affect the global greenhouse gas emissions trend, and how this compares to emissions trajectories consistent with the long-term goal of the United Nations Framework Convention on Climate Change (UNFCCC). The difference has become known as the emissions gap. In addition to estimating the emissions gap, the reports focus on key options for achieving the emissions reductions necessary to bridge the gap, and provide an assessment of how these can be accelerated and scaled up. Countries have found these emissions gap assessments useful in informing the political process.

In line with previous reports, the objective of the 2016 Emissions Gap Report is to provide an up-to-date scientific assessment of the global progress towards the emissions reductions required to be on track to meet the long-term goal of the UNFCCC. In particular, this year the report emphasizes the implications of the Paris Agreement’s strengthened goal of holding the increase in the global average temperature to well below 2°C, and to pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels for immediate and longer-term mitigation action (Chapters 2 and 3).

In line with previous years, the report assesses actions in selected areas that can contribute to bridging the emissions gap, and how these can be accelerated and scaled up. Previous reports have covered a wide range of areas, including agriculture, forestry, and renewable energy. The areas selected this year are non-state action (Chapter 4); energy efficiency (Chapter 5); and the nexus between the Sustainable Development Goals and climate change mitigation (Chapter 6).

Non-state action and energy efficiency have been examined in earlier reports, but increased political focus on these options and availability of new studies that provide better understanding of their large emissions reduction potential, in combination, provides a strong rationale for revisiting these options.

Particularly, this report presents policies that have proven to accelerate energy efficiency gains in the building sector which involve:

1. Building energy codes. The existence of a building energy codes alone does not guarantee emission reductions. To ensure their effectiveness, the following principles need to also be adopted:

• Compliance monitoring and enforcement are essential. Typically, limited human and financial resources for this activity will be a key barrier to the successful implementation of building codes.
• The design of building energy codes should follow a holistic approach, covering energy performance, quality and safety, and utilisation of renewable energy.
• The stringency of building energy codes should be regularly revisited and strengthened. Leapfrogging to very high efficiency performance standards have also been demonstrated and avoid lock-in.

2. Building information and energy performance certification. It is recommended that before adopting energy performance certification programmes for buildings developed in the past, countries should carefully examine their stringency from the perspective of carbon lock-in, and the energy and emissions performance requirements should be brought as close to the state-of-the-art as possible.

3. Highly energy efficient buildings. These include the passivehaus standard, net-zero energy buildings, and energy positive (or e+) buildings.