BlogAR6 Report Key Takeaways
This Synthesis Report (SYR) of the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6) summarises the state of knowledge of climate change, its widespread impacts and risks, and climate change mitigation and adaptation, based on the peer-reviewed scientific, technical and socio-economic literature since the publication of the IPCC’s Fifth Assessment Report (AR5) in 2014.
This report identifies opportunities for transformative action that are effective, feasible, just, and equitable using concepts of systems transitions and resilient development pathways.
Section 2: Current status and trends
Observed Changes, Impacts, and Attribution
- In this section it is presented that the cause of global warming/climate change is attributed to human activities mainly because of greenhouse gas emissions.
- Dominant GHGs that contribute to the warming are carbon dioxide (CO2) and methane (CH4), partly masked by aerosol cooling.
- According to the data, there is high confidence that current CO2 concentrations are higher than at any time over at least the past two million years. - The main contributors to the net GHG emissions and consequently to climate change are energy use, land-use and land use change (LULUC), way of living of an individual or group, and patterns of consumption, and production.
- Furthermore, there is inequality in the effects of climate change and contributions to the emissions. Communities who are more vulnerable are affected the most even though their historical contribution is the least.
- “The 10% of households with the highest per capita emissions contribute 34–45% of global consumption-based household GHG emissions, while the middle 40% contribute 40–53%, and the bottom 50% contribute 13–15%.” (Data from AR6 report) - Observed Climate System Changes and Impacts to Date:
- Ocean warming - increase in sea level, the global retreat of glaciers, decrease in Arctic sea ice area, decreased Northern Hemisphere spring snow cover, and surface melting of the Greenland ice sheet, ocean acidification (a reduction in the pH of the ocean over an extended period of time, caused primarily by uptake of carbon dioxide (CO2) from the atmosphere).
- Changes in weather and climate extremes - heatwaves (more frequent and more intense), heavy precipitation, droughts, and tropical cyclones.
- Climate change has caused substantial damages, and increasingly irreversible losses, in terrestrial, freshwater, cryospheric, and coastal and open ocean ecosystems.
- Reduction in food and water security
- In urban locations, climate change has caused adverse impacts on human health (physical and mental), livelihoods, and key infrastructure (transportation, water sanitation, and energy system)
- Disproportionality in the effects of climate change on the most vulnerable people and systems.
Responses Undertaken to Date
- Responses and factors that help push forward an agenda to address climate change at governance level are:
- International climate agreements, e.g. UNFCCC, Kyoto Protocol, and - Paris Agreement
- increasing public awareness
- rising national ambitions for climate action
- etc. - An increase in policies and laws that support mitigation actions has contributed to a decrease in global energy and carbon intensity. This is achieved through:
- efficient energy use - is the use of less energy to perform the same task or produce the same result.
- reduced rates of deforestation - the purposeful clearing of forested land
- energy supply decarbonisation - moving away from fossil fuel energy supply to renewable energy sources, and a new mix of low-carbon generation technologies, including gas with Carbon Capture Utilisation and Storage (CCUS), nuclear, hydrogen, and energy storage (batteries and others).
It is important to note that climate governance enables mitigation by
- providing overall direction
- setting targets
- mainstreaming climate action across policy domains and levels - With design and process improvements/innovations and the use of digital technologies the unit cost of renewable energy technologies such as solar, wind, and lithium-ion batteries has drastically decreased since 2010.
- Adaptation planning and implementation progress have generated multiple benefits, with effective adaptation options having the potential to reduce climate risks and contribute to sustainable development.
- Global tracked finance for mitigation and adaptation has seen an upward trend since AR5 but falls short of needs.
Current Mitigation and Adaptation Actions and Policies are not Sufficient
- Adaptation is the process of adjusting to the current and future effects of climate change.
- Mitigation means preventing or reducing the emission of greenhouse gases (GHG) into the atmosphere to make the impacts of climate change less severe.
Even though there are improvements in adaptation, the gaps exist between what is needed versus what is the current level of adaptation. One of the main problems is that many initiatives are short-sighted, focusing on immediate and temporary risk reductions.
Factors that slow down adaptation progress are:
- insufficient levels of financing/funding
- lack of climate literacy and data
- knowledge and experience
Section 3: Long-term climate change
Based on the IPCC assessment of all the scenarios and modeled pathways global warming will persist and reach new records in the near term future. In order to prevent the temperature from exceeding the agreed threshold of 1.5 °C or less than 2°C by 2100 it is essential to reduce GHG emissions very quickly and continuously over a long period of time.
Every increment in temperature matters
Every temperature increase drastically worsen resultant damages, risks, and extremes in climate. Projected adverse impacts and related losses and damages from climate change escalate with every increment of global warming. They are expected to
- expand to more regions
- be more significant
- be more frequent
- be more widespread
On top of the above many regions are projected to experience an increase in the probability of compound events with higher global warming, such as concurrent heatwaves and droughts, compound flooding, and fire weather.
A climatic impact-driver is a physical climate condition that directly affects society or ecosystems. Climatic impact-drivers may represent a long-term average condition (such as the average winter temperatures that affect indoor heating requirements), a common event (such as a frost that kills off warm-season plants), or an extreme event (such as a coastal flood that destroys homes).
CDR - carbon dioxide removal
AFOLU - agriculture forestry and other land use
Long-term adaptation options and limits
The effectiveness of adaptation to reduce climate risk is documented for specific contexts, sectors, and regions and will decrease with increasing warming
Integrated, cross-cutting multi-sectoral solutions increase the effectiveness of adaptation.
Losses and damages, strongly concentrated among the poorest vulnerable populations, will increase
Integrated, cross-cutting multi-sectoral solutions increase the effectiveness of adaptation
Mitigation Pathways
Pathways consistent with 1.5°C and 2°C carbon budgets imply rapid, deep, and in most cases immediate GHG emission reductions in all sectors
The best estimates of the remaining carbon budget (RCB) from the beginning of 2020 for limiting warming
- to 1.5°C with a 50% likelihood is estimated to be 500 GtCO2
- for 2°C (67% likelihood) this is 1150 GtCO2
In order to limit human-caused global warming to a specific level the following requirements need to be met:
- limiting cumulative CO2 emissions
- reaching net zero or net negative CO2 emissions
- strong reductions of other GHG emissions
Reductions in GHG emissions in industry, transport, buildings, and urban areas can be achieved through a combination of energy efficiency and conservation and a transition to low-GHG technologies and energy carriers.
Models of pathways where global warming is limited to 2°C or below, show that:
- almost all electricity is supplied from zero or low-carbon sources, such as renewables or fossil fuels with CO2 capture and storage
- energy demand is electrified across-the-board
- land-based mitigation and land-use change is implemented, with most including different combinations of reforestation, afforestation, reduced deforestation, and bioenergy
Furthermore, factoring in and implementing Carbon Dioxide Removal (CDR) can help with fulfillment of the following:
- lowering net CO2 or net GHG emissions in the near term
- counterbalancing ‘hard-to-abate’ residual emissions (e.g., some emissions from agriculture, aviation, shipping, and industrial processes) to help reach net zero CO2 or GHG emissions
- achieving net negative CO2 or GHG emissions if deployed at levels exceeding annual residual emissions
Long-Term Interactions Between Adaptation, Mitigation, and Sustainable Development
Shifting development pathways towards sustainability and advancing climate-resilient development is enabled when governments, civil society, and the private sector make development choices that prioritise risk reduction, equity, and justice, and when decision-making processes, finance, and actions are integrated across governance levels, sectors, and timeframes
Combining mitigation with action to shift development pathways, such as broader sectoral policies, approaches that induce lifestyle or behaviour changes, financial regulation, or macroeconomic policies can overcome barriers and open up a broader range of mitigation options