Without immediate and deep cuts in emissions from all sectors, limiting global warming to 1.5 degrees above pre-industrial levels is out of reach, the Intergovernmental Panel on Climate Change (IPCC) insisted on Monday 4 April, when it published its new report.
This is the third and final part of the IPCC’s Sixth Assessment Report on the state of scientific knowledge on climate change.
The first, published last August, dealt with the physical understanding of the climate system and climate change (see EUROPE 12787/10). The second, unveiled at the end of February, focused on the impacts, adaptation and vulnerability of human societies and ecosystems to climate change (see EUROPE 12900/17). The final volume details the solutions available to mitigate climate change.
It is therefore more political in nature than the previous two components, even though the IPCC reports do not aim to make recommendations (whether it be for energy policy, transport, agriculture, etc.), but rather to assess and synthesise the research on climate change that has been published around the world.
In a sign of this political dimension, the approval of the third part, which was due to be completed on Friday 1 April, was postponed until Monday morning due to a delay in the intergovernmental negotiations aiming to validate, line by line, the summary of the report for the decision-makers.
Is 1.5 degrees an unattainable goal?
While the Paris Agreement has set a target of containing the rise in global average temperature to well below 2°C above pre-industrial levels and striving to limit it to 1.5°C, the IPCC shows that annual average global greenhouse gas (GHG) emissions are at an all-time high, even though the growth in these emissions slowed between 2010 and 2019.
The IPCC therefore stresses the importance of drastically reducing global greenhouse gas (GHG) emissions during this decade.
According to the report, net GHG emissions are expected to peak by 2025 at the latest and to fall by 43% by 2030 (-48% for CO2 and -34% for methane) and 84% by 2050 compared to 2019 levels in scenarios that limit warming to 1.5°C, with “no or limited” temporary overshoot.
To limit warming to 2°C, these reductions would have to be 27% and 63% respectively for the two periods.
The 1.5°C target is therefore still achievable in theory, but requires “immediate and significant emission reductions in all sectors”, the IPCC warns.
“We must act now or 1.5ºC will be out of reach, it will be physically impossible to achieve”, insisted Jim Skea, co-chairman of the working group behind the report (working group III), at the press conference presenting the report.
While she also stressed the urgency of ambitious measures, Céline Guivarch, research director at the International Research Centre for Environment and Development (CIRED) and one of the main authors of the report, warned against the risk of focusing on the 1.5ºC target.
Referring to the second part published in February, she said: “Each additional fraction of a degree means additional impacts, risks and damage [...] 1.5 degrees is not an absolute threshold, it is each fraction of a degree that counts”.
Strengthening climate change policies
The report also highlights the inadequacy of current policies and announced measures.
Policies implemented by the end of 2020 are thus expected to result in a median global warming of 3.2°C by 2100.
If the ‘Nationally Determined Contributions’ announced before COP26 in Glasgow are met until 2030, warming is expected to be around 2.8°C and it will be impossible to limit warming to 1.5°C with ‘no or limited’ overshoot.
“The world is not on the right track to limit global warming and its worst effects. Only immediate and ambitious measures in all sectors and at all levels can rapidly reduce greenhouse gas emissions”, Ms Guivarch summarised.
Solutions
Solutions to contain global warming do exist, however, the IPCC points out.
For the first time, the IPCC devotes a chapter to mitigating demand effects, including changes in diets, transport patterns and material efficiency.
According to the report, the right policies, infrastructure and technologies to change our lifestyles and behaviours can lead to a 40-70% reduction in GHG emissions by 2050, while improving well-being.
In particular, it stresses that reducing emissions requires a “substantial reduction in the overall use of fossil fuels”.
However, demand-side measures will not be sufficient.
“Deployment of carbon dioxide removal to offset hard-to-remove residual emissions is unavoidable if net zero CO2 or GHG emissions are to be achieved” the paper says.
See the report: https://aeur.eu/f/13r
See the summary for decision-makers: https://aeur.eu/f/13q (Original version in French by Damien Genicot)