IPCC AR6 Synthesis report - Climate Change 2023

[edit] The second Spring Budget attracting less attention

Looking across the construction industry press this week is a very different picture than it was looking across the press the afternoon that the UK Spring Budget was published. Whilst the latter formed headlines across the board, with comments from various industry leaders, the publication of the latest IPCC synthesis report appears in only one or two news headlines and mostly from climate focussed press.

As an industry contributing to over 40% of emissions, is the report just too weighty to be news worthy? Does the industry already know the message from the previous report? Is this one too harsh or complex to know how to respond? Is it too distant from the day-to-day industry news? Or all of the above?

Whatever the reasons, this report represents the last in a series, that might impact this decade, a decade seen as the most important and very last chance to affect a 1.5 or 2.0 degree scenario. Its message is a clear and unequivocal code red alarm, and call for deep, immediate and unrelenting cuts in emissions from every industry.

[edit] A summary of the last 5 years

The IPCC AR6 synthesis report is a summary of the last 5 years of reports published through the 6th Assessment Cycle which ran from 2018 to 2023. The next cycle and reporting, the Seventh Assessment, is not expected before at least 2027. This report is therefore seen as the last benchmark with a chance to impact the critical next seven years up to 2030.

The primary message is clear on all levels, that climate change in unequivocally the result of human induced greehouse gas (GHG) emissions, and that changes and impacts are already being seen, whilst current adaptation and mitigation measures fall politically and financially short of what is needed. It says "There is a rapidly closing window of opportunity to secure a liveable and sustainable future for all", that rapid and deep cuts need to be made effectively immediately over this decade to achieve the net zero goal required to stay below 1.5 degrees. Anything less is likely to see an increase of between 1.5 and 2 degrees.

[edit] Key IPCC points on current status and trends

Observed warming and causes - Unequivocal that GHG emissions through human activities have caused global warming.

Observed changes and Impacts - Widespread, rapid changes in atmosphere, ocean, cryosphere and biosphere have occurred affecting many weather and climate extremes in every region across the globe.

Current progress in adaptation and gaps and challenges - Progress across all sectors and regions, with varying documented benefits but gaps exist and grow as global financial flows are insufficient and constrain implementation.

Current mitigation progress, gaps and fhallenges - Policies and laws have consistently expanded, GHG emissions implied by NDCs (Nationally determined contributions) make it likely warming will exceed 1.5°C and make a limit below 2°C harder. Gaps between projected emissions from policies and NDCs, finance flows fall short of the levels needed to meet climate goals.

[edit] Key IPCC points on future climate change, risks, and long-term responses

Future climate change - Continued GHG emissions will lead to increasing global warming, with the best estimate of reaching 1.5°C in the near term, every increment of global warming will intensify multiple and concurrent hazards. Deep, rapid, and sustained reductions would lead to a slowdown within around two decades.

Climate change impacts and climate-related risks - higher than assessed in AR5, risks, projected adverse impacts, related losses and damages escalate with every increment of global warming. Climatic and non-climatic risks will increasingly interact, creating compound and cascading risks that are more complex and difficult to manage.

Likelihood and risks of unavoidable, irreversible or abrupt changes - Some changes are unavoidable and/or irreversible but can be limited by deep, rapid and sustained global greenhouse gas emissions reduction. The likelihood of abrupt and/or irreversible changes increases with higher global warming levels. Similarly, the probability of low-likelihood outcomes associated with potentially very large adverse impacts increases with higher global warming levels

Adaptation options and their limits in a warmer world - Those effective today become constrained and less effective with increasing global warming. Loss and damage will increase, additional human and natural systems will reach limits. Maladaptation can be avoided by flexible, multi-sectoral, inclusive, long-term planning and implementation of actions, with co-benefits to many sectors and systems.

Carbon budgets and net zero emissions - Limiting warming requires net zero CO2 emissions. Cumulative carbon emissions until then and reductions this decade determine the possibility to limit to 1.5°C or 2°C. CO2 emissions from existing fossil fuel infrastructure without additional abatement would exceed the remaining carbon budget for 1.5°C.

Mitigation pathways - All modelled pathways of 1.5°C with no or limited overshoot, and 2°C involve rapid, deep immediate reductions in all sectors this decade. Global net zero CO2 emissions are reached for these pathway categories in the early 2050s and around the early 2070s, respectively.

Overshoot: exceeding a warming level and returning - If warming exceeds 1.5°C, it could gradually be reduced by achieving and sustaining net negative global CO2 emissions. Requiring additional deployment of carbon dioxide removal, compared to pathways without overshoot. Overshoot entails adverse impacts, some irreversible, risks for human and natural systems, growing with the magnitude and duration.

[edit] Key IPCC points on responses in the near term

Urgency of near-term integrated climate action - rapidly closing window of opportunity to secure a liveable and sustainable future for all. Climate resilient development integrates adaptation and mitigation, enabled by increased international cooperation including improved access to adequate financial resources, particularly for vulnerable regions, sectors and groups, inclusive governance, coordinated policies. The choices and actions this decade will have impacts now and for thousands of years.

The benefits of near-term action - Deep, rapid and sustained mitigation and accelerated implementation of adaptation actions in this decade would reduce losses and damages for humans and ecosystems, and deliver co-benefits, air quality and health. Delayed mitigation and adaptation action would lock-in high-emissions infrastructure, raise risks of stranded assets and cost-escalation, reduce feasibility, and increase losses and damages.

Mitigation and adaptation options across systems - Rapid transitions across all sectors and systems are necessary to achieve deep reductions and secure a liveable and sustainable future for all. Involves a significant upscaling

Synergies and trade-offs with sustainable development - Accelerated and equitable action in mitigating and adapting to climate change impacts is critical to sustainable development, more synergies than trade-offs with Sustainable Development Goals. Synergies and trade-offs depend on context and scale of implementation.

Equity and inclusion - Prioritising equity, climate justice, social justice, inclusion and just transition processes can enable adaptation and ambitious mitigation actions and climate resilient development. Enhanced by increased support to regions and people with the highest vulnerability, Integrating into social protection programs improves resilience. OPtions for reducing emission-intensive consumption, inc behavioural and lifestyle changes, with co-benefits.

Governance and policies - Effective climate action is enabled by political commitment, well-aligned multilevel governance, institutional frameworks, laws, policies and strategies, enhanced access to finance and technology. Clear goals, coordination across domains, and inclusive governance facilitate effective climate action. Regulatory and economic instruments can support deep emissions reductions and climate resilience if scaled up and applied widely.

Finance, technology and international cooperation - Finance, technology and international cooperation are critical enablers for accelerated climate action. If climate goals are to be achieved, both adaptation and mitigation financing need to increase many-fold. There is sufficient global capital to close the global investment gaps but there are barriers to redirect capital to climate action. Enhancing technology innovation systems key to accelerate the widespread adoption of technologies and practices. Enhancing international cooperation is possible through multiple channels.

This article is based on the IPCC AR6 Synthesis Report: Climate Change 2023 available on their website here