What does the new Intergovernmental Panel on Climate Change Synthesis report mean for people and forests?
9 mai 2023
The Intergovernmental Panel on Climate Change’s (IPCC) Sixth Assessment (AR6) cycle culminated with the March 2023 publication of a report synthesising the findings of the science, impacts and adaptation, and mitigation Working Groups. The Summary for Policy Makers (SPM) of the Synthesis Report (SYR SPM) underscores the urgency of taking deep, effective action in the coming decade, and was agreed, line by line, by Government delegates.
As such publications are long and dense, Fern has gone through it to bring the main takeaways concerning forests and forest-dependent peoples.
Science
In 2019, we reached 1.07°C above pre-industrial temperatures. Even with very steep greenhouse gas (GHG) reductions, we will likely reach 1.5°C within two decades. Each added increment of global warming brings larger extremes in climate impacts, and a weakening of land and ocean carbon sinks such that they absorb a decreasing proportion of rising emissions.
The report highlights “a rapidly closing window of opportunity to secure a liveable and sustainable future for all. The choices and actions implemented in this decade will have impacts now and for thousands of years.”
Impacts and adaptation
Impacts from warming are now understood to be worse, and the risks greater, than noted in the 2014 Fifth Assessment Report. Human and ecosystem vulnerability are interdependent, and strongly influenced by unsustainable consumption and production, and persistent unsustainable management of land, ocean and water. Ecosystem loss has cascading impacts on global populations – most directly, Indigenous Peoples and local communities.
Climate change has already caused substantial losses and adverse impacts across all ecosystems, approaching irreversibility in cases such as glacier retreat and permafrost thaw. Adverse impacts and losses to nature and people are unequally distributed, and intensifying. Increased drought, wildfires and precipitation changes are most likely to affect forests.
“[M]any changes will be irreversible on centennial to millennial time scales and become larger with increasing global warming. Without urgent, effective, and equitable mitigation and adaptation actions, climate change increasingly threatens ecosystems, biodiversity, and the livelihoods, health and wellbeing of current and future generations.”
Mitigation
Reductions of GHG emissions this decade will largely determine whether global warming can be limited to a 1.5°C or 2°C rise. Various mitigation scenarios modelled potential strategies, from pathways that limit warming to 1.5°C to those exceeding 4°C, with serious social and environmental impacts. The effects of drastic warming illustrate the urgency of climate action to avoid or minimise ‘overshoot’ and to reduce reliance on contentious carbon dioxide (CO2) removal (CDR).
Deep, near-term reductions in CO2 and non-CO2 GHG – such as a 34 per cent cut in methane by 2030 - would reduce projected losses and damages for humans and ecosystems; delaying beyond this decade will further push human and natural systems to a point at which it is not possible to adapt.
Very low and low emissions pathways that limit overshoot are less reliant on CDR and expect to achieve ‘net zero’ between 2050 and 2070, followed by a period of CDR. All such pathways require more ambitious GHG reductions this decade than appear in any country’s Nationally Determined Contributions (NDCs).
The report prominently underscores concerns about the feasibility and sustainability of large-scale CDR deployment, as well as the social and environmental risks. Nevertheless, it foresees that CDR will be necessary to compensate for hard-to-abate GHG emissions such as from agriculture, aviation, and shipping, and to lower atmospheric CO2 concentrations after overshooting a temperature threshold.
Any overshoot will lead to a spiral of adverse impacts, increasing with the magnitude and duration of overshoot: more wildfires, mass tree deaths, drying peatlands, thawing permafrost, and weakening natural land carbon sinks.
All these increase GHG releases which means there is more need for CDR, which the IPCC makes clear has risks of its own:
“Biological CDR methods like reforestation, improved forest management, soil carbon sequestration, peatland restoration […] can enhance biodiversity and ecosystem functions, employment and local livelihoods. However, afforestation or production of biomass crops can have adverse socio-economic and environmental impacts, including on biodiversity, food and water security, local livelihoods and the rights of Indigenous Peoples, especially if implemented at large scales and where land tenure is insecure.”
Activities such as conservation, and improved management and restoration of forests fall into the sector known as agriculture, forestry and other land use (AFOLU). They provide cost-effective adaptation and mitigation benefits that could quickly be upscaled.
As tropical deforestation causes the majority of land-sector emissions, it offers the highest mitigation potential. It is important to integrate ecosystem restoration, reforestation and afforestation so as to minimise competing demands on land while meeting multiple objectives. Activities such as shifting to sustainable healthy diets and reducing food waste could also reduce land-use and associated emissions, while actions such as conservation of peatlands, wetlands, rangelands, mangroves and forests deliver immediate benefits.
Although land restoration takes longer to deliver climate benefits, it enhances ecosystem services, and yields economically positive returns and benefits for poverty reduction and improved livelihoods. The report makes it clear that “cooperation and inclusive decision-making, with Indigenous Peoples and local communities, as well as recognition of inherent rights of Indigenous Peoples” are integral.
Fern’s takeaways
The need for effective action could not be more pressing. More than its predecessors, this report hones in on the urgency of reducing emissions this decade, while presenting a balanced picture of the role of forests and ecosystems. The report highlights the mitigation benefits of avoided deforestation and ecosystem restoration when based on effective governance and recognising rights, while acknowledging the inherent risks in relying on CDR.
Catégorie: Forest Watch