Impact case study database

Policy Implementation: Reading’s RE calculations made significant contributions to tabulations of metrics presented by IPCC in AR4 [S1] and AR5 [S2]. These have subsequently been used to implement climate policy worldwide. Several examples follow, first considering UNFCCC and then other policy applications.

First, the 2012 Doha Amendment to the UNFCCC Kyoto Protocol, which covers emissions in the period between 2013 and 2020, added NF₃ [R1] to its list of GHG emissions to be included in national commitments, using its AR4 GWP(100) value. This Amendment was accepted by 146 of the current 147 signatory countries during the REF2021 Impact Period. In November 2013, the UNFCCC adopted AR4 GWP(100) values in its requirement for countries to report their annual CO₂e emissions. Then in November 2018, under the UNFCCC Paris Agreement, which supersedes the Kyoto Protocol, it formally adopted AR5 GWP(100) values [R4] for this reporting. Similarly, in May 2020, the European Union (EU) adopted AR5 GWP values in its regulations for member states to report their greenhouse gas emissions from 1 January 2021 onwards [S3].

A specific policy focus has been HFC emissions, because of their growing usage in air-conditioning units in buildings and vehicles, and other sectors, including refrigeration. UNFCCC data shows that CO₂e emissions from developed nations (Annex 1) rose by a factor of three between 1990 and 2017, whereas total CO₂e emissions remained almost constant. Thus, HFC emissions constituted a growing percentage of the total (for example now 3% in UK, 3.5% in Japan). To curb future growth, there have been widespread efforts to move to low-GWP HFC alternatives. The legislation, some of which is detailed in the next paragraph, is reliant on reliable GWP (and hence RE) values for its implementation.

In 2014, the EU Fluorocarbon Gas Regulation adopted AR4 GWP values. This regulation mandated that HFC usage in different sectors should be phased out between 2015 and 2025. As an important example, the EU identified one gas, HFC-32, as being a technologically feasible low-GWP alternative. Its RE, in AR4, originates from Reading-led research that resolved earlier disagreements [R2, S1]. This regulation led to a major shift in HFC usage, for example, in air conditioning units manufactured by Mitsubishi UK. In 2018, the European Environment Agency reported a subsequent 54% (CO₂e) reduction in HFC usage in the EU, relative to 2011-2013, which is an indicator of the regulation’s success. Japan (in 2016) and Canada (in 2019) implemented similar legislation that required HFC GWP values. The 2016 Kigali Amendment to the UN’s Montreal Protocol on Substances that Deplete the Ozone Layer [S4] set binding targets for reducing HFC emissions in developed and developing nations based on AR4 GWP(100) values. This Amendment entered into force (i.e. became legally binding) in January 2019 and is currently ratified by 112 countries [S4].

Contribution to Policy Debate: Reading’s work on alternative metrics (GTP and GWP*) to the GWP has impacted public policy by enabling a debate on the most appropriate metrics for use in meeting specific climate policy objectives. Prior to AR5, no proposed alternatives had gained traction with policymakers, and the GWP had been the only metric recommended by IPCC. Thus, GWP, and specifically GWP(100), became UNFCCC’s established standard metric. In 2013, tabulated values of GTP were included, for the first time, in IPCC’s AR5 [R5, S5]; unlike earlier IPCC assessments, AR5 refrained from specifically recommending any particular metric, GWP(100) or otherwise.

The GTP is used in numerous national and international contexts. As examples, the Norwegian Environment Agency adopted it in its 2016 action plan to reduce emissions of short-lived climate pollutants; and in 2016, the UN Environment Program-hosted Life Cycle Initiative (which includes many governmental and industrial funding partners) recommended the GTP(100) as one of three climate indicators in Life Cycle Impact Assessment [S6].

The GTP is also discussed in some Nationally Determined Contributions (NDCs) which embody efforts by each country to reduce national emissions under the UNFCCC Paris Agreement. Brazil’s 2016 NDC states that the GTP is “most consistent with contributions to hold the increase in global average temperature below 2°C above pre-industrial levels” (i.e. the specific aim of the Paris Agreement). Uruguay’s 2016 NDC highlights the AR5 comment that “the GWP metric is not directly related to a temperature limit, as the 2°C target ..., whereas other metrics like the GTP may be more suitable …” [S7].

In 2018, a UN climate agreement included specific mention of the GTP for the first time. The UNFCCC’s 2018 decision to adopt the AR5 GWP(100) values (see above and [S3]) was accompanied by the statement that “each Party may … also use other metrics (e.g. global temperature potential) to report supplemental information on aggregate emissions …”. This reflects an ongoing, unresolved debate within the UNFCCC’s Subsidiary Body for Scientific and Technological Advice (SBSTA), which noted: “limitations in the use of GWPs based on the 100-year time horizon in evaluating … emissions of [gases] with short lifetimes” [S8].

In the short time since the GWP* was proposed, it has already impacted on the policy debate, particularly for countries and sectors that are major methane emitters because of the scale of their agricultural activity. Shine played a significant role in disseminating the concept to stakeholders, including a side-event at the UNFCCC COP23 (Bonn, 2017), and invited talks at the Climate and Clean Air Coalition’s Scientific Advisory Panel Expert Workshop (Ottawa, 2017) and IPCC’s Expert Meeting on Short-lived Climate Forcers (Geneva, 2018).

The most notable policy impact of GWP* was its role in motivating a new treatment of agricultural methane emissions by New Zealand in their national climate legislation. New Zealand’s 2019 Climate Change Response (Zero Carbon) Amendment Act sets separate targets for emissions of (1) long-lived greenhouse gases, aiming for net zero by 2050, and (2) biogenic methane emissions, aiming for a reduction of 24 to 47% below 2017 levels by 2050. Targets were set on the advice of New Zealand’s Productivity Commission which had concluded that the GWP* can “help people make better decisions about mitigation.” This decision is now reflected in New Zealand’s 2020 NDC [S9].

The GWP* was considered in detail by the UK Committee on Climate Change in their 2020 report ‘Land use: Policies for a Net Zero UK.’ A joint statement by agricultural organisations in the UK and New Zealand, including the National Farmers’ Union, supported the adoption of the GWP*. Furthermore, the International Dairy Sustainability Framework (IDSF) launched a project to examine “the potential benefits and disadvantages for the global ruminant sector of applying GWP*,” with the IDSF acting on behalf of organisations including Arla Foods, International Dairy Federation, McDonalds, and Meat and Livestock Australia [S10].

In summary, Reading’s research has contributed directly to climate policy, by providing results that are required to implement methods for placing emissions of non-CO₂ greenhouse gases on a CO₂e scale. These methods are needed to enact both international climate policy and policies developed by individual nations and groups of nations. Reading’s work has regularly updated those results, in the light of improved understanding, and it has helped enable the calculation of values for an increasing number of such gases. Its contribution to definitive tabulations in international climate assessments has enabled their wide uptake by stakeholder communities throughout the world and hence influenced mitigation actions, most notably in the area of fluorocarbon emissions. Its work on methodologies for placing emissions on CO₂e scales has contributed to an ongoing debate within the UNFCCC, and beyond, on the most appropriate methodologies. This has influenced the framing of mitigation actions by individual nations and stakeholder communities. Thus, Reading’s research has had both a global reach and a significant influence on an important component of international and national environmental policymaking.