What are “science based targets”?

Climate science terminology filters through slowly to religious institutions so this post explores an approach to reducing carbon emissions that was first implemented in 2015. Being fair, the scheme is aimed at large multi-national business so we can, perhaps, be forgiven for not being a little slow on the up-take. Having said this it provides a much more reasoned and practical response to the climate emergency than simply declaring that we will become net-carbon neutral by some specific date in the future.

The basic approach is quite simple. Companies are asked to consider one of the IPCC scenarios providing a timeline for global carbon emissions required to limit global average temperature rise to a specific value and set two targets for the emissions for which they are responbsible. The first “near-term” target has to be within the next 5-10 years and a longer “net-zero” target represents long-term ambitions (typically envisaging minimal emissions from 2050 onwards). Both targets need to be set in the context of the company’s measured emissions in a specified baseline year (typically between 2015 and 2020).

The approach pre-dates the most recent IPCC sixth assessment reports but recommends scenarios in line with the Paris Agreement to limit warming to 1.5°C above pre-industrial levels. This limits the choice of the five scenarios in the IPCC Working Group 1 Report to the first (SSP1-1.9) and the corresponding timeline of carbon emissions is depicted in the diagram below.

The key points are labelled. To be compatible with this scenario, global emissions will need to drop to 58% of 2020 levels by 2030 and 5% by 2050. Science based target setting would require a company to adopt similar targets for its own emissions. (Needless to say, this is a rather simplified explanation of the concepts. If you want more detail then there is plenty at sciencebasetargets.org.)

There are several advantages to this approach over simply aiming for net-zero by a specific date. The most obvious is that the reasoned approach to setting a target in line with the overall global requirement is something that all stakeholders will be able to understand (and hopefully that most will agree to buy in to). If all companies adopt similar strategies then the approach offers the possibility to ensure fair competition within any particular sector. Adopting just two clearly stated targerts will further aid clarity.

Targets obtained using this methodology tend to be moderate and realistic. Reducing emissions to 58% of 2020 levels by 2030 will require year on year reductions of less than 5% of 2020 emissions (if commenced in 2022). Acheiving 5% of 2020 levels over the nexty 20 years will only require about half this.

The methodology does not specify the use of any particular scenario so companies could choose to be more or less ambitious or to select scenarios that are specific to the industrial sector in which they operate rather than global emissions used in this example.

Another advantage is in the detail which prevents companies using carbon offsetting or avoided emissions in calculating their carbon footprint. Both are difficult to calculate and even more difficult to verify. Both offer the temptation for companies to buy their way out of responsibilities rather than reducing emissions directly. Under scientific target setting, companies are expected to nominate targets for the emissions for which they are actually responsible and then buy carbon removal for any residual emissions that cannot be avoided.

There are three disadvantages. The most obvious is that the approach assumes that all companies will engage with the process. If some do not, then emissions reductions from those who have will not be sufficient to keep global emissions within the requirements of the chosen scenario. This is particularly important given that it is likely to take some time for science based targetting to filter down to the wide range of global small and medium sized enterprises that are so important in driving the world economy (and responsible for so much of its carbon emissions).

The second is that the approach assumes that all geographical regions and industrial sectors should reduce emissions at the same rate in relation to current emissions. Many more affluent areas of the world have excessive emissions and it can be argued that they should have much more aggressive targets than the average upon which science-basd targets are based. Less affluent areas often have historically low emissions. Industries serving such areas will almost certainly need to increase emissions to provide populations with products and services that we regard as essential. Neither is there any consideration of whether all industrial sectors should be considered equal. There is a strong argument that providers of luxury goods and services, for example, should be required to reduce emissions at a higher rate than providers of essentials such as food, education and healthcare.

The third disadvantage is that many scenarios depend on carbon removal using technologies that do not yet exist but are assumed will emerge over the next thirty years. It can be seen from the graph above, for example, that scenario SSP1-1.9 envisages net zero being achieved in 2055 with increasing amounts of CO2 being removed from the atmosphere in the second half of the century (up to about a third of our current rate of emissions being removed by 2100). Hidden in the detail behind SSP1-1.9 is that net zero is only envisaged as attainable by 2055 if large scale carbon removal has commenced by 2030 (see this Twitter thread).

On balance, although there are disadvantages, science based targetting is a much more considered approach than adopting essentially arbitrary net-zero targets based on aspiration alone. Most of the disadvantages amount to concerns that the targets, being based on an ideal global response, will be insufficient given how the real world operates. This would suggest that the current approach should be regarded as the bare minimum, and that companies engaging with the process should be encouraged to adopt more ambitious targets.

Should churches adopt science based targets?

Most of the major denominations within the United Kingdom have now declared an ambition to be carbon neutral by a certain date. Action for Hope, the Methodist Church in Britain’s response to the climate emergency, includes an aspiration to be net carbon neutral by 2030 (matching a similar commitment by the Church of England). Whilst such an aspiration is laudable, I have not seen any analysis of whether it is achievable. 2030 still seems a long way off, but anyone who has given serious consideration to the action that their local church would need to take to free itself from dependence on carbon must be daunted by the challenge. Whilst a small number of highly committed churches will make appropriate changes, duplicating this across all the churches within British Methodism will be a huge challenge.

Being an aspiration to net carbon zero, of course, we have effectively given ourselves an opt-out clause. We can simply do our best (regardless of whether it is good enough or not) and then purchase offsets to cover our shortcomings. Without putting some sort of ceiling on the amount of offsetting that we regard as acceptable, a commitment to net carbon neutral is not really a committment to anything at all (other than making a financial payment to cover our failures).

The combination of an aspirational target that looks increasingly impossible to achieve and an opt-out clause to let us off the hook, is likely to undermine committed attempts to achieve that aspiration in any other than a few highly committed churches. Using a science based tagetting approach to set more reasonable aims and to limit our reliance on off-setting may offer a more considered path to sharing our environmental responsibilities.

Of course the big advantage of setting an early date for net-carbon neutrality is the sense of urgency this conveys – however we modify our approach, it is important that we don’t lose that sense of urgency. This is a real problem which we need to start addressing now.

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