All Parties’ emissions in 2017 were below their base-year level, which in many cases means that they have already achieved their 2020 targets. However, for a number of Parties whose emissions in 2017 were between their baseyear level and targeted emission level for 2020, the emission reductions achieved by 2017 are not commensurate with the target reductions by 2020, in terms of either emission level or emission budget, as relevant. Those Parties are expected to make further efforts to meet their 2020 targets by strengthening the implementation of existing PaMs. Some Parties have already indicated their intention to use units from market-based mechanisms and, if applicable, the contribution of LULUCF towards achieving their 2020 targets.

The overall decline in GHG emissions since 1990 reflects primarily the impact of the economic transformation of EIT Parties in the 1990s and the strengthening of climate change mitigation actions by almost all Parties in the second half of the 2000s and after 2010. These actions include promoting the increased use of less carbon-intensive fuels and of renewable energy in the electricity mix and improving energy end-use efficiency in the energy sector, as well as PaMs in the agriculture and waste sectors. Those measures have been accompanied by modernizing and enhancing the efficiency of industrial processes and reducing the livestock population.

Most Parties view their 2020 targets as a waypoint on the trajectory towards their midterm and long-term targets under the Paris Agreement. They are capitalizing on their experience in implementing PaMs by tailoring their portfolios to target the key emitting sectors and to include PaMs that are cost-efficient and can bring co-benefits, such as health benefits and job creation, in addition to emission reductions. Parties’ 2030 NDC targets, long-term goals or targets (e.g. carbon neutrality or net zero emissions by 2050) and LT-LEDS feature prominently in Parties’ reporting. Many Parties described their plans to transition to low-emission economies and societies, with newly reported PaMs being part of their strategies for achieving their 2030 and 2050 targets.

Key long-term policy objectives include making renewables the main source of electricity while phasing out coal and electrifying building heating systems and road transport. Parties reported on new near-term actions needed to meet these goals, such as building infrastructure for electric transportation and scheduling the retirement of coal power plants. The majority of Parties are or envisage using carbon pricing approaches in some form. Many Parties reported on combining carbon pricing approaches in the form of levies or taxes and trading systems.

In their BR4s, Parties reported a total of 2,749 PaMs, with estimated 2020 impacts reported for 30.0 per cent of them, totalling emission reductions of 6,238.81 Mt CO2 eq. A trend of measures moving through a ‘life cycle’ is evident throughout the four biennial reporting cycles as successful actions are replicated and expanded, imperfect policies are reformulated and strengthened, and ineffective policies are discontinued. The trend is manifested in a higher share of planned and adopted, but not yet implemented, measures being reported in the BR4s than in previous BRs and indicates that Parties have started planning actions towards achieving their post-2020 targets. For example, the EU ETS has been substantially revised for its fourth phase (2021–2030). Planning for achieving post-2020 targets also includes strengthening institutional structures and processes, for example with regard to planning mitigation actions, tracking progress against targets and evaluating the effectiveness of implemented PaMs.

Projections made in 2017 (the most recent reported year in GHG inventories) show a 13.6 per cent decrease in total GHG emissions excluding LULUCF by 2020 compared with the 1990 level and a 1.2 per cent decrease compared with the 2017 level under the WEM scenario, which takes into account implemented and adopted PaMs. Despite the increased scope and expected strengthening of mitigation actions for beyond 2020, total emissions under the WEM and WAM scenarios are projected to decline by only 0.4 and 4.0 per cent, respectively, between 2020 and 2030. This suggests that implemented and planned mitigation actions may not be sufficient to completely offset the impact of the underlying emission drivers, such as economic and population growth, and to drive emissions down after 2020. It may also suggest that the impacts of the planned mitigation actions reported in the BR4s aimed at achieving the 2030 targets have not been fully accounted for because the impacts depend on what form the legislative and regulatory frameworks supporting their implementation, which have yet to be finalized, will take.

As reported in the BR4s, total climate support reached an annual average of USD 52.2 billion in 2017–2018; on a comparable basis, this represents a 5.9 per cent increase over the previous biennium 2015–2016. 7 Both Annex II Parties and Annex I Parties not included in Annex II8 provided quantitative or qualitative information on climate finance in their BR4s on climate-specific support (funds targeted specifically at climate action) and core/general support (funds that are not specifically targeted at climate action). One third of the total support (an average of USD 18.4 billion per year over the biennium 2017–2018) was allocated through multilateral channels, with over half allocated to mitigation, followed by cross-cutting and adaptation. As in the previous biennium, multilateral development banks represent the largest share of multilateral finance institutions for channelling climate finance. Multilateral climate finance funds, such as the Green Climate Fund, are now also attracting considerable funding, allowing them to channel expanded support for climate action in developing countries.

The BR4s demonstrate some new developments, including expanded use of innovative financial instruments such as insurance, a move towards more detailed sectoral reporting, improved tracking of private sector finance and the introduction of voluntary reporting on issues such as gender. In addition, more Annex I Parties not included in Annex II reported on climate support provided to non-Annex I Parties in the BR4s than in any previous BRs. Parties also demonstrated ongoing efforts to expand their tracking and reporting of private sector finance leveraged by public investments, thereby helping to clarify the bigger climate finance picture.

In their BR4s, Parties reported 425 activities relating to technological support (40 per cent more than in the BR3s), with more than half of the activities supporting mitigation (56 per cent), a quarter supporting adaptation (28 per cent) and the remainder supporting cross-cutting action (a similar pattern to that presented in the BR3s). Annex II Parties highlighted their efforts to fully respond to developing country Parties’ needs, as identified by 53 non-Annex I Parties in their technology needs assessments and contained in the fourth synthesis report on technology needs identified by non-Annex I Parties. Deploying mature technologies remained the predominant supported activity, but support for technology research and development and demonstration activities has increased since the BR3s, in line with the need to support research and development and facilitate access to technology highlighted in the Paris Agreement. The Asia-Pacific region continued to benefit most from the reported technological support, with 43 per cent of all reported technological support activities focusing on that region.

In the BR4s, 702 capacity-building activities were reported, a significant increase (77.7 per cent) on the 395 activities reported in the BR3s. The reported capacity-building activities cover all 15 priority areas outlined in the framework for capacity-building in developing countries established under decision 2/CP.7. Continuing the trend observed from the BR3s, the most significant share of capacity-building was for adaptation (40.0 per cent) and this support was mostly focused on integrating climate resilience into existing and new infrastructure or on promoting green transformation in agriculture and forestry. Mitigation accounted for 28.6 per cent of capacity-building, primarily aimed at strengthening monitoring and evaluation. Geographically, the majority of the capacity-building support for adaptation was provided to the Asia-Pacific and Africa regions. Mitigation support was primarily provided for multiregional or global projects.

These systems, which are supported by domestic institutional frameworks and international technical reviews under the UNFCCC, lay the groundwork for a successful transition to the enhanced transparency framework under the Paris Agreement. In addition, Parties without reporting obligations under the current system have voluntarily reported on support (e.g. Annex I Parties not included in Annex II reporting on financial, technological and capacity-building support provided to developing country Parties), which has helped them to gain reporting experience and facilitated the development of reporting systems and approaches to help them prepare for the transition to the enhanced transparency framework. Developed countries have demonstrated a deep understanding of how their climate policies are performing over time and how they affect emission levels. As well as contributing to the quality of reporting under the UNFCCC, the establishment of systems for ensuring transparency of climate action and support has facilitated domestic policymaking by providing policymakers with access to accurate, reliable and up-to-date information on emission levels, impacts of mitigation actions and support provided.