Credit: UNFCCC
Credit: UNFCCC

IPCC Special Report: Why sector-specific vision for 1.5°C is important

Sector-based analysis in IPCC Special Report offers an alternative vision for limiting warming to 1.5 C

The Inter-Governmental Panel on Climate Change (IPCC) is close to finalising its Special Report on 1.5°C. The report, which will be published on October 8, will evaluate the prospect of meeting the target outlined in the Paris Agreement—limiting global average temperature increase to less than 1.5°C over pre-industrial levels. The threshold has long been considered by scientific experts as an important one, crossing which will significantly increase the risks and impacts associated with climate change.

The process of finalising the ‘1.5°C Report’ has been highly contentious. Drafts of the Report’s “Summary for Policymakers” were leaked in January and June, and have been subjected to intense scrutiny for evidence of political interference in scientific consensus. The controversy is less about the existence of human-induced climate change, and more about how quickly we are likely to experience the catastrophic impacts, and what it would take to pull ourselves away from this self-harming trajectory.

The latter question—determining a pathway away from harm—is the subject of analysis in the latest available draft summary of the Special Report. The draft (leaked in June) states that “[l]imiting global warming to 1.5°C would require rapid and far-reaching systems transitions occurring during the coming one to two decades, in energy, land, urban, and industrial systems”. The focus on these sectors is not new. They have long been identified as the largest contributors to global greenhouse gas emissions.

The IPCC’s 5th Assessment Report (published in 2014), which had the relevant statistics for 2010, claimed that 35 per cent of emission was attributed to the energy sector, 24 per cent (net emissions) to land use change, 21 per cent to industry, 14 per cent to transport and 6.4 per cent to the building sector. This was part of a consistent pattern: the bulk of the increase in GHG emissions between 2000 and 2010 came from the energy (47 per cent), industry (30 per cent), transport (11 per cent) and building (3 per cent) sectors.

However, beyond identifying these GHG-intensive sectors, this latest draft offers a glimpse into their future trajectory. If the energy sector is serious about achieving the 1.5°C target, the carbon intensity of all sources of electricity must be zero by the middle of this century. For that to happen, it is desirable that in 2050, renewable energy forms 49–67 per cent of the energy mix, while coal accounts for 1–7 per cent.

For the industry sector to stay on the right side of the 1.5°C threshold, the draft indicates that its emissions should be about 70-90 per cent lower in 2050, as compared to 2010. It also indicates that such a trajectory is achievable through “combinations of novel technologies and practices”, including low-emission electrification, hydrogen, bio-based feedstock, product substitution, and carbon capture and storage. However, it also notes that there are economic and institutional barriers preventing widespread adoption of these solutions.

The latest draft is not as specific about the land, buildings and transport, limiting itself to stating that “transitions in global and regional land use are required to limit warming to 1.5°C” and that “[t]ransport and buildings, and their associated infrastructure, achieve deep emission reductions by 2050 in 1.5°C-consistent pathways”. It does identify some critical technologies such as energy-efficient appliances, insulation and electrification, and lifestyle choices such as walking or cycling that can play an important role in the transition.

An earlier draft summary of the report (leaked in January) did indicate that electricity, hydrogen and biofuel-based solutions should account for 36 per cent of total energy use in the transport sector in 2050, but this figure has been dropped from the June draft. It remains to be seen whether numerical projections for the future of the land, buildings and transport sector will make it into the final report.

This sectoral analysis is important because discussions at the UNFCCC have, so far, focused largely on trying to set economy-wide targets to avoid getting into the weeds of different economic sectors. This has resulted in a “least common denominator” approach to target setting, exemplified by the lack of any emission target in the Paris Agreement. If we are to make a more coordinated push to limit warming to 1.5°C, perhaps the sector-based analysis in this IPCC Special Report offers an alternative vision.

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