TODAY’S STUDY: THE UN’S EMISSIONS SOLUTION

Bridging the Emissions Gap
November 2011 (United Nations Environment Program)

Executive Summary

Global climate policy has advanced on several fronts over the past few years and this report deals with two developments of particular importance – The readiness of countries to pledge to new emission reductions, and the agreement among countries to an important global climate target. In December, 2009, countries were encouraged to submit pledges for reducing greenhouse gas emissions for the year 2020 as part of the Copenhagen Accord. Subsequently, 42 industrialized countries and 44 developing countries submitted pledges. At the climate conference in Cancún one year later, parties formally recognised country pledges and decided “to hold the increase in global average temperature below 2°C above pre-industrial levels”. They also left open the option for “strengthening the long-term global goal on the basis of best available scientific knowledge including in relation to a global average temperature rise of 1.5°C”. An obvious and basic question is, to what extent will the country pledges help to meet the 2°C and 1.5°C targets?

A year ago, UNEP convened 25 scientific groups to assess this question. In their “Emissions Gap Report” released in December, 2010, the scientists reported that a gap was expected in 2020 between expected emissions and the global emissions consistent with the 2°C target, even if pledges were implemented fully. After receiving the report, policymakers requested UNEP to prepare a follow-up document which not only updates emission gap estimates, but more importantly, provided ideas on how to bridge the gap. This present report is a response to this request. To do the work UNEP has convened 55 scientists and experts from 28 scientific groups across 15 countries.

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This report first reviews and summarizes the latest scientific studies of the gap. It then tackles the question – How can the gap be bridged? – by examining the question from different vantage points: From that of global integrated assessment models, from bottom-up studies of individual economic sectors, and from published work on the mitigation potential in international aviation and shipping emissions. These different perspectives provide a rich body of information on how to plausibly bridge the emissions gap in 2020 and beyond.

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1. Is it possible to bridge the emissions gap by 2020?

The answer to this question is, yes. Many different scientific groups have confirmed that it is feasible to bridge the emissions gap in 2020 between business-as-usual emissions and emission levels in line with a 2°C target.

The gap can be bridged by making realistic changes in the energy system, in particular, by further increasing its efficiency and accelerating the introduction of renewable energies (See point 3).

From the viewpoint of different sectors of the economy, the gap can be bridged by pursuing a wide range of technically feasible measures to reduce emissions in different sectors (See point 3).

Furthermore, policy instruments to realize these emission reductions have already been applied successfully in many countries and sectors.

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2. What is the emissions gap in 2020?

Although the country pledges help in reducing emissions to below a business-as-usual level in 2020, they are not adequate to reduce emissions to a level consistent with the 2°C target, and therefore lead to a gap. Estimates of this gap (6-11 GtCO2e) are larger than reported in the 2010 UNEP Emissions Gap report (5-9 GtCO2e) but are still within the range of uncertainty of estimates.

The size of the gap depends on the extent to which the pledges are implemented and how they are applied, what accounting rules are assigned, and the desired likelihood of staying below a particular temperature limit.

As a reference point, the gap would be about 12 GtCO2e (range: 9-18 GtCO2e) between business-as-usual emissions (i.e if no pledges are implemented) and emissions consistent with a “likely” chance (greater than 66 per cent) of staying below the 2°C temperature target. This figure is nearly as large as current total greenhouse gas emissions from the world’s energy supply sector.

Four cases are considered which combine assumptions about pledges (unconditional or conditional) and rules for complying with pledges (lenient or strict). (For an explanation, see footnote1).

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Under Case 1 – “Unconditional pledges, lenient rules”, the gap would be reduced to about 11 GtCO2e (range: 7-16 GtCO2e) or to a rounded value2 of 2 GtCO2e below business-as-usual (earlier estimate = 9 GtCO2e).

Under Case 2 – “Unconditional pledges, strict rules”, the gap would be about 9 GtCO2e (range: 6-14 GtCO2e), or 3 GtCO2e below business-as-usual (earlier estimate = 8 GtCO2e).

Under Case 3 – “Conditional pledges, lenient rules”, the gap would also be about 9 GtCO2e (range: 6-14 GtCO2e) or 3 GtCO2e below business-as-usual (earlier estimate = 7 GtCO2e).

Under Case 4 – “Conditional pledges, strict rules”, the gap would be about 6 GtCO2e (range: 3-11 GtCO2e) (earlier estimate = 5 GtCO2e). This is 6 GtCO2e lower than business-as-usual conditions, and of the same magnitude as current total greenhouse gas emissions from the world’s entire transport sector. On the positive side, fully implementing the pledges halves the gap from business-as-usual conditions; in other words, brings emissions 50 per cent of the way to the 2°C target.

The gap could still be 1-2 Gt CO2e larger if double counting of emissions reductions by developed and developing countries due to the use of the carbon market is not ruled out and if the additionality of CDM projects is not improved.

The estimate of the size of the gap has increased mostly because of two factors:

(1) some developing countries have increased the baseline to which their pledges are connected, which reduces the effect of these pledges;

(2) the Kyoto Protocol surplus emissions are estimated to be higher because of the economic recession, which reduces the effect of pledges in the “lenient rules” cases.

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To stay within the 2°C limit, global emissions will have to peak soon

Emission pathways consistent with a “likely” chance of meeting the 2°C target have a peak before 20203, and have emission levels in 2020 around 44 GtCO2e (range: 41- 46 GtCO2e). Afterwards, global emissions steeply decline (an average of 2.6 % per year, with a range of 2.2-3.1 %)4, and/or reach negative emissions in the longer term.

Accepting a “medium” (50-66 %) rather than “likely” chance of staying below the 2°C target relaxes the constraints slightly: emissions in 2020 could be 2 GtCO2e higher, and average rates of global reduction after 2020 could be 2.5 per cent per year (range 2.2-2.9 %). Nevertheless, global emissions still need to peak before 2020.

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A 1.5°C target can also be met, but it won’t be easy

With regards to a 1.5°C target, the 2020 emission levels with a “likely” chance of staying within the 2°C limit are about the same as those with a “medium” or lower chance of meeting the 1.5°C target. However, to meet the 1.5°C target the emission reduction rates after 2020 would have to be even faster than for a 2°C target.

To stay within the 2°C limit, global emissions in 2050 will have to be considerably lower than now

As far as emissions in 2050 are concerned, to have a likely chance of complying with the 2°C target, total greenhouse gas emissions in 2050 must be about 46% lower than their 1990 level, or about 53% lower than their 2005 level.

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3. How can the gap be bridged?

The gap can be narrowed by resolving some immediate climate negotiation issues. Possible actions to narrow the gap include:

• Implementing the more ambitious “conditional” pledges. This would reduce the gap by 2-3 GtCO2e

• Minimizing the use of “lenient Land Use, Land Use Change and Forestry (LULUCF) credits” and surplus emission credits. This would reduce the gap by 2-3 GtCO2e

• Avoiding the double-counting of offsets and improving the additionality of CDM projects. Double-counting could increase the gap by up to 2 GtCO2e.

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Modelling studies show that it is feasible to bridge the gap: Global integrated assessment models indicate that it is possible, with technically and economically feasible measures, to bridge the emissions gap in 2020 between business-as-usual emissions and emissions consistent with the 2°C target. In particular, intervening in the energy system can be a successful strategy for reducing emissions.

Nine different scientific groups have used global integrated assessment models to identify low emission pathways consistent with the 2°C target. Thirteen scenarios from these groups have been reviewed in this report. All of these scenarios reduce greenhouse gas emissions to the 2020 level consistent with a 2°C target, principally by modifying the energy system. Looking across these studies, they achieve low emissions in 2020 by a combination of the following:

• Improving energy efficiency: Primary energy production is up to 11% lower than business-as-usual levels in 2020 (with one study 18% lower). The amount of energy used per unit GDP decreases around 1.1 - 2.3% per year from 2005 to 2020.

• Producing up to 28% of total primary energy from non-fossil fuel energy sources in 2020. (As compared to 18.5% in 2005).

• Producing up to 17% of total primary energy in 2020 from biomass. (As compared to about 10.5% in 2005).

• Producing up to 9% of total primary energy in 2020 with non-biomass renewable energy (solar, wind, hydroelectricity, other). (As compared to about 2.5% in 2005).

• Reducing non-CO2 emissions up to 19% relative to business-as-usual in 2020 (with one estimate of 2%). It is important to note that the preceding numbers are maximum values for the different mitigation options, and that different mitigation scenarios had different mixes of these options. For example, different scenarios had varying percentages of biomass and non-biomass renewable energy. In fact, every scenario had a different mix indicating that there are many pathways to bridging the gap.

Globally, the marginal costs of these packages of measures range from about US $25 to US $54 per ton of equivalent carbon dioxide removed, with a median value of US $38 per ton (with one estimate of US $15, and another of US $85).

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Detailed studies of different sectors also show that it is feasible to bridge the gap: A review of these studies confirms that pursuing a wide range of technically feasible measures can deliver more than enough emission reductions to fully close the gap between business-as-usual emissions and emissions in line with the 2°C target.

Many ‘bottom-up’ studies have been carried out that articulate the potential to reduce emissions in various economic sectors. These studies differ from the analyses of global integrated assessment models by focusing on individual sectors. A review of these studies shows the following potential for reducing global emissions in 2020:

• The electricity production sector: 2.2 to 3.9 GtCO2e per year through more efficient power plants, introducing renewable energy sources, introducing carbon-capture-and-storage, and fuel shifting.

• The industrial sector: 1.5 to 4.6 GtCO2e per year through improvements in energy efficiency, fuel switching, power recovery, materials efficiency improvements, and other measures.

• The transportation sector (excluding aviation and shipping): 1.4 to 2.0 GtCO2e per year through improvements in fuel efficiency, adoption of electric drive vehicles, shifting to public transit, and use of low carbon fuels.

• The buildings sector: 1.4 to 2.9 GtCO2e per year through improvements in the efficiency of heating, cooling, lighting, and appliances, among other measures.

• The forestry sector: 1.3 to 4.2 GtCO2e per year through a reduction in deforestation, and changes in forest management that increase above and below ground carbon stocks.

• The agriculture sector: 1.1 to 4.3 GtCO2e per year through changes in cropland and livestock management that reduce non-CO2 emissions and enhance soil carbon.

• The waste sector: about 0.8 GtCO2e per year through improved wastewater treatment, waste gas recovery from landfills, and other measures.

The total emission reduction potential of these sectors in 2020 adds up to about 16 ± 3 GtCO2e (the full range is 16 ± 7 GtCO2e. The reduced range assumes that not all sectors are at the high end of their range simultaneously). Adding the aviation and shipping sectors sum up to a total emission reduction potential of 17 ± 3 GtCO2e (the full range is 17 ± 7).

Marginal costs of reduction extend up to around 50 - 100 US$/tCO2e.

One conclusion is that the 12 GtCO2e emissions gap in 2020 (between business-as-usual emissions and emission levels in line with the 2°C target), can be bridged by realizing the mid-range estimate of the emission reduction potential.

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There is also potential to reduce international emissions from aviation and shipping

Emissions from the aviation and shipping sectors are a special case compared with other sectors because a large fraction of global civil aviation and shipping emissions are “international” and not fully attributable to a particular country. International emissions have not been included in the Kyoto Protocol targets for Annex I countries and they do not fall under country pledges. Therefore, we take a separate look at potential emission reductions from these sectors.5

As of 2006, 62% of the emissions from aviation were international, and as of 2007, 83% from shipping were international. The 2005 emissions from global civil aviation were about 0.6 GtCO2 per year and about 1.0 GtCO2 per year from global shipping. Together they account for about 5% of global CO2 emissions. Business-as-usual projections for 2020 are about 0.6 to 1.2 GtCO2 per year from aviation and 1.1 to 1.3 GtCO2 per year from shipping.

Many studies have examined the potential for reducing emissions from these sectors. Options for reducing emissions from both sectors include improving fuel efficiency and using low-carbon fuels. For the shipping sector, another promising and simple option is to reduce ship speeds.

Summed together, the two sectors are estimated to have a potential for reducing emissions in 2020 of about 0.3 to 0.5 GtCO2e, which is additional to the potential of other sectors reported in bottom-up studies, leading together to a total of 17 ±3 GtCO2e.

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Bridging the gap is possible in many ways

To sum up, policymakers have many options for narrowing and closing the emissions gap in 2020.

They can agree within the context of climate negotiations to implement their more ambitious “conditional” pledges, and in fulfilling these pledges they could minimize the use of “lenient LULUCF credits” and surplus emission credits. They could also agree to avoid the double-counting of offsets and make these offsets really additional.

They could target their energy systems and make them more efficient in 2020 than they otherwise would be under “business-as-usual” conditions. Other goals would be to produce a larger share of their total primary energy from non-fossil fuel sources, with more primary energy from modern biomass and other sources of renewable energy in some combination. They could also reduce their non-CO2 emissions significantly.

By making energy use more efficient, and accelerating the use of renewable energy, they will be able to substantially reduce emissions coming from their electricity production, industrial, transportation, buildings, aviation and shipping sectors. But many other measures are also feasible for these sectors.

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Policymakers could also pursue better management as a strategy for reducing emissions from the forestry, agricultural and waste sectors. Reducing deforestation and improving forestry management would increase carbon stocks relative to a baseline, and changing farm and waste management practices would, in particular, be an effective strategy for reducing non-CO2 emissions.

Based on the large body of scientific studies reviewed in this report, it is clear that no major technological breakthrough will be needed to substantially reduce emissions by 2020. A great potential already exists to reduce emissions, and costs of these reductions are not prohibitive. Indeed, a wide range of policy instruments for mitigating greenhouse gas emissions have already been adopted and are in use in many different sectors and countries throughout the world, and these instruments are successful in reducing emissions.

And if the potential for reducing global emissions was to be realized, then the world would be on track to keep the rise in average global temperature to below 2.0 or 1.5 degrees by 2020. It would still be possible to bridge the emissions gap in 2020 and stay on a pathway to long-term climate protection.