Production and consumption of ozone-depleting substances

The 1987 Montreal Protocol is recognised globally as one of the most successful multilateral environmental agreements to date. Its implementation has led to a decrease in the atmospheric burden of ODS in the lower atmosphere and in the stratosphere. The schedule for the limitation and phase-out of the consumption of ODS, as defined in the Montreal Protocol, is summarised in the accompanying indicator specification.

The EU regulation on substances that deplete the ozone layer (ODS Regulation, 1005/2009/EC), which in many aspects goes further than the Montreal Protocol, also brings forward the phasing out of hydrochlorofluorocarbons (HCFCs) from 2020, and introduces an HCFC new-fill ban and a servicing ban. These bans are related to the placing on the market and use of non-virgin HCFCs that are prohibited in the EU for the maintenance or servicing of existing refrigeration, air-conditioning and heat pump equipment. Moreover, with only a few exemptions, the prohibition of imports and exports of products and equipment containing or relying on ODS, including HCFCs, is also brought forward. It also includes a total ban on the use of methyl bromide, including quarantine and pre-shipment applications.

Consumption of ODS decreased significantly in the EEA-33, particularly in the first half of the 1990s. Figure 1 shows that the EEA-33 phased out its use of ODS at a faster rate than the world average. Today it is practically zero.

ODS consumption in the EEA-33 fell from approximately 420 000 ODP tonnes in 1986 to negative values in 2002. Since 2002, values have been negative, except for the years 2003, 2006 and 2012, when they were slightly positive. The value in 2015 was -3 808.88 ODP tonnes.

Consumption is a parameter that gives an idea of the presence of ODS on the market and tracks progress in phasing out these chemicals. It is calculated for each calendar year and is mainly defined as 'production plus imports minus exports' (quantities destroyed or used in certain applications like feedstock or quarantine and pre-shipment services are subtracted where relevant). As such, its formula can yield a negative number when substances are produced and imported in quantities that do not compensate for the amounts exported or destroyed. This usually happens when export or destruction take place for ODS that were previously on the market in the EEA-33 (stocks). Additionally, different substances have different ODP values. If consumption is calculated in ODP tonnes, a negative value is also obtained when production/imports take place for low-ODP substances and export/destruction take place for high-ODP substances. The latter is the current situation due to the fact that certain high-ODP substances are produced in the EU as by-products which, in general, are stocked before being destroyed.

A closer look at individual ODS substance groups reveals that the phase-out of chlorofluorocarbons (CFCs), halons, 1,1,1 trichloroethane (TCA), hydrobromofluorocarbons (HBFCs), bromochloromethane (BCM) and carbon tetrachloride (CTC) was implemented by the EU according to the agreed schedule under the Montreal Protocol. However, the phase-out of methyl bromide (MB) took three additional years to be completed (due to remaining critical uses approved by the parties to the Protocol). The effects of the HCFC freeze under the Montreal Protocol and the HCFC new-fill ban under the ODS Regulation can also be clearly observed.

Globally, consumption of ODS controlled under the Montreal Protocol declined by some 98.36 % worldwide between 1986 and 2016.

However, much remains to be done to ensure that the damage to the ozone layer is reverted. Initiatives to further reduce releases of ODS could involve the following:

• Addressing the strong growth in the production and consumption of HCFCs in developing countries;
• Collecting and safely disposing of the large quantities of ODS contained in old equipment and buildings (the so-called ODS 'banks');
• Ensuring that restrictions on ODS continue to be properly implemented and the remaining worldwide use of ODS declines further;
• Preventing illegal trade in ODS; and
  
• Strengthening the international and European framework on ODS (e.g. inclusion of other known ODS, restricting exemptions).

In the EEA-33, exemptions to the overall phase-down mean that ODS are still used to the extent allowed by the Montreal Protocol and the ODS Regulation (applying to the EU-28). The exempted uses concern 'critical uses', 'feedstock uses', 'process agent uses' and 'laboratory and analytical uses'.

Table 1 (Figure 2) shows an estimate of the quantities of substances covered by the Montreal Protocol that are used within the EU for the above-mentioned uses as reported to the EEA (2016 reporting year, coverage EU-28).

For 'feedstock' and 'process agent use', known to have very low emission factors (0.17 % and 1.05 %, respectively), actual emissions are also to be reported by the companies concerned. These low emission factors are one of the reasons why these two uses operate with less stringent rules under the Montreal Protocol and the EU legislation on ODS. However, given that the Montreal Protocol targets have generally been achieved for the EEA-33 and worldwide, the importance of these emissions subsequently becomes more apparent. Therefore, any future changes to the rules affecting these uses could potentially result in additional environmental benefits.

The current reporting framework on ODS in the EU does not include reporting on emissions for laboratory uses or critical uses. It is also not possible to reliably estimate these emissions due to the multitude of technologies and industry-sites involved. Instead, these figures are meant to show which ODS uses are still relevant in the EU today and could be a future target of additional operational rules.

The EU has already gone beyond the rules of the Montreal Protocol to tackle some of the remaining challenges. Among these actions, as previously mentioned, the ODS Regulation introduced a new-fill ban and a servicing ban affecting HCFCs. The ODS Regulation also covers new substances in addition to those controlled under the Montreal Protocol.

Table 2 (Figure 3) shows the combined ODP of the substances covered by both the Montreal Protocol and the ODS Regulation. It becomes apparent that the additional substances covered by the ODS Regulation only ('new substances') are especially relevant as feedstock and industrial solvents (many 'new substances' are used for this latter purpose). The substitution of traditional ODS with these newer ones is a relatively recent trend and is closely monitored by the EEA.

There is also scientific evidence that chemicals other than those covered by the Montreal Protocol and the ODS Regulation are playing a role in the depletion of ozone. In particular, very short-lived substances, such as dichloromethane, could have a negative impact. Given their uncontrolled growth of around 60 % over the last decade, they might delay ozone recovery by 30 years. Adequately managing the use and releases of other known ODS represents a challenge that will need to be addressed by the international community and the EU.

Maximum ozone hole area over the southern hemisphere, historically (9 September 2000) and currently (11 September 2017)

Note: False-colour view of total ozone over the North (Arctic) and South (Antarctic) poles. The purple and blue colours indicate the lowest ozone presence, while yellow and red indicate higher ozone presence. Ozone concentration is commonly measured in Dobson Units. One Dobson Unit is the number of molecules of ozone that would be required to create a layer of pure ozone 0.01 millimetres thick at a temperature of 0 degrees Celsius and a pressure of 1 atmosphere.

Data source:

• Ozone Hole Watch provided by NASA

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Depletion of stratospheric ozone occurs over both hemispheres of the Earth. However, this phenomenon is significantly less severe in the northern hemisphere (Arctic) than in the southern hemisphere (Antarctica). This is the case because year-to-year meteorological variability is larger over the Arctic than over the Antarctic. Furthermore, temperatures in the stratosphere do not remain low for a long time in the Arctic as is the case in the Antarctic.

Generally, concentration levels of 200 Dobson Units (DU) or less (represented in blue/violet in the images) are technically considered to represent severe ozone depletion and constitute the so-called ozone hole. This is only apparent in the southern hemisphere. Here, the largest historical extent of the ozone hole was reached on 9 September 2000, with 29.9 million square kilometres (Figures 4 and 5). This area is equivalent to almost seven times the territory of the EU.

Overall, the ozone hole has shown signs of healing since 2000, which is mainly attributable to the phasing out of ODS under the Montreal Protocol. However, the extent of the ozone hole is also periodically influenced by volcanic eruptions, increasing the stratospheric particle load and thereby depleting ozone. This mostly explains occasional years with a comparatively large ozone hole, such as 2015.

The extent of the ozone hole seems to be stagnating with a slight positive prospect. Currently, the ozone hole showed a maximum area of 19.6 million km² on 11 September 2017 (Figures 4 and 5). Ozone recovery is also visible in terms of minimum ozone concentrations. During the last five years (2013-2017), the average lowest concentration was 115.2 DU while over the ten preceding years (2007-2017) it reached an average value of 122.0 DU.

However, the mitigation of ozone depletion is still very fragile and scientific evidence suggests that more action is still required to remove pressure on the ozone layer caused by ODS.