The Intergovernmental Panel on Climate Change (IPCC) of the United Nations is the foremost entity devoted to advancing scientific knowledge about anthropogenic climate change. Established in 1988, the agency carries out the biggest and most internationally-recognised peer reviewed process in the scientific community on climate change. The premier authority on climate change has recently wrapped up its sixth assessment, following the March 2023 release of its Synthesis Report (AR6). The 8.000-page IPCC Sixth Assessment Report (AR6) is the most comprehensive and ambitious study ever conducted by the intergovernmental body and the “starkest warning yet” to be delivered.
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The Sixth Assessment Report is the last of six major comprehensive reports released by Intergovernmental Panel on Climate Change (IPCC) since 1988. Within climate change broadly, they have published 14 specific reports on particular topics such as ocean and cryosphere, land use, and renewable energy.
Peer-reviewed sources are a foundational core of the IPCC’s body of work. Indeed, the Panel does not carry out its own research, but rather assesses scientific papers and independent findings from other scientific bodies and entities. Through this kind of research, the IPCC carries out three distinct working groups:
- Working Group I: Assesses the physical science basis of climate change.
- Working Group II: Assesses climate change Impact, adaption, and vulnerability.
- Working Group III: Assesses mitigation of climate change.
It is estimated that over 8,000 scientists from 195 different countries have contributed to the IPCC reports throughout the years. The collective efforts of governments, the private sector, civil society, and academia are vital to the approval, adoption, and acceptance phases of each published report.
Common themes are found in the potential destruction caused by rising greenhouse gases (GHG), including rising global temperatures, extreme weather events (droughts, floods, etc.), and sea level rise. Fortunately, it is not all gloom and doom. There is still time, but we must make immediate steps now to limit warming to 1.5C, the critical threshold agreed upon by 195 countries with the 2015 Paris Agreement. That is only possible through immediate actions to curb greenhouse gas emissions, with the intent of halving emissions by 2030.
As stated in the Sixth Assessment Report: “The magnitude and rate of climate change and associated risks depend strongly on near-term mitigation and adaptation actions, and projected adverse impacts and related losses and damages escalate with every increment of global warming.”
8 Key Findings from IPCC 6th Assessment Report
1. Climate change is happening, it is the result of reckless human activities and a threat to human and natural systems
The IPCC AR6 states that: “Human-caused climate change is a consequence of more than a century of net GHG emissions from energy use, land-use and land use change, lifestyle and patterns of consumption, and production.”
For decades, humans have been burning fossil fuels to produce energy needed to manufacture things like cement, iron, steel, electronics, plastics, clothes and other goods and have been cutting down forests at unprecedented rates to free up land for urban development and agricultural land. These activities release large amounts of greenhouse gases into the atmosphere, which trap heat and cause global temperatures to rise.
Global fossil fuel consumption has more than doubled in the last 50 years, as countries around the world aim to improve their standards of living and economic output. In 1971, the world consumed approximately 4 billion metric tons of oil. In 2018, the number surpassed 8 billion metric tons. The rate of deforestation has also been increasing since 2015, with an estimated 10 million hectares of primary forest being cleared each year. Current agricultural practices are not sustainable in the long term, as they lead to a range of environmental problems, such as soil erosion, water pollution, and biodiversity loss. The greenhouse gas emissions associated with these practices are an issue as well. Around 25% to 30% of global emissions nowadays come from our food systems and agricultural products, according to estimates.
Carbon dioxide (CO₂) emissions from fossil fuels and industry. Land use change is not included. Image: Our World in Data.
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2. Global temperatures are rising, glaciers are melting, and sea levels are rising
The average global temperature has increased by over 0.08C (0.014F) since the pre-industrial era and is projected to keep rising in the coming decades. As the climate heats up, rainfall patterns change, evaporation increases, glaciers melt, and sea levels rise. Global surface temperature has increased faster since 1970 than in any other 50-year period over at least the last 2,000 years.
The likely range of total human-caused global surface temperature increase from 1850-1900 to 2010-2019 is 0.8C to 1.3C, with a best estimate of 1.07C. Sea-level rise projections show that, even if the world follows a low greenhouse gas pathway, the level of sea rises globally will continue to rise up to about 0.7 meters by the end of this century. This risks the displacement of one in every 10 people on the planet and triggers massive economic, social, and cultural disruptions worldwide.
The rate at which glaciers are disappearing has risen 57% since the 1990s, and under current warming trends, two-thirds of Earth’s glaciers may vanish by 2100. The global mass of glaciers decreased by an average of 0.42 metres of water equivalent per year between 2000 and 2019. Additionally, the rate of melting has increased sharply, with an average loss of 0.75 meters of water equivalent per year in the same timeframe and potential catastrophic consequences for hundreds of millions of people worldwide.
Humans are responsible for changes in global surface temperature. Image: Figure 2.1 IPCC AR6 SYR.
3. The frequency and intensity of extreme weather events are increasing
Extreme weather events include floods, heatwaves, droughts, and tropical cyclones.
These events are capable of causing huge loss of lives and properties. The scientific community unanimously agrees that global warming is exacerbating the intensity of these events as it increases the evaporation of surface waters into the atmosphere, affecting rain patterns worldwide. Several studies provide undeniable evidence that rising global temperatures have made events such as the Horn of Africa drought and last year’s record-breaking heatwaves in the Northern Hemisphere up to 100 times more likely. More than half of the global population already contends with severe water scarcity for at least one month per year and by 2050, droughts might affect up to two-thirds of the world’s population.
The role of anthropogenic climate change in extreme weather events. Image: Nature.
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4. Oceans acidification is accelerating, biodiversity is decreasing, and water is becoming increasingly scarce
Ocean acidification has increased by 30% since pre-industrial times and is expected to continue rising in the future. This sharp increase in acidity has devastating impacts on marine ecosystems, leading to decreases in biodiversity and the collapse of fisheries.
Biodiversity is decreasing due to habitat destruction, overfishing, and, of course, climate change. The rate of species extinction is estimated to be 100 to 1,000 times higher than the natural background rate. This rate refers to the rate of carbon dioxide concentration in the atmosphere before industrialisation, estimated at around 280 parts per million (the current rate around 420 ppm). If global warming reaches 4C, findings in AR6 suggest that around 4 billion people are projected to experience water scarcity with additional adaptations (food insecurity, technological improvements, etc.). Currently, roughly half of the world’s population is already experiencing severe water scarcity for at least some part of the year due to a combination of climatic and non-climatic drivers.
Sea level rise will continue for millennia, depending on future emissions. Image: Figure 3.4 IPCC-AR6-SYR.
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5. Climate Change is exacerbating existing inequalities
Climate change is exacerbating inequalities, as vulnerable communities and developing countries are disproportionately impacted by its effects. For example, those living in poverty are more likely to be affected by extreme weather events, such as floods and droughts, due to a lack of access to resources, health services and adequate infrastructure. Despite their almost insignificant contribution to global greenhouse gas emissions, households in the bottom 50% of incomes are already being disproportionately affected by the effects of climate change and will continue to be the most impacted in the future. Additionally, those living in low-lying coastal areas are more likely to be affected by sea level rise.
Feedback loop of more extreme heat and drought. Image: Figure 4.3 IPCC-AR6-SYR.
6. The global economy is vulnerable to the impacts of climate change
The destruction brought about by extreme weather events such as floods and droughts results in unimaginable economic losses. Moreover, these events can disrupt global supply chains, leading to huge economic losses. If temperatures increase on the current trajectory and the Paris Agreement and 2050 net-zero emission targets are not met, the world could risk losing around 10% of total economic value from climate change. If greenhouse gas emissions are left unchecked (with risks of global average temperature increase surpassing 3C), we could see as much as 18% of global GDP eroded by mid-century. Climate-related risks for natural systems and humans, including food and water insecurity, land degradation, spread of diseases, and conflicts, are higher in a 1.5C-scenario than at present.
7. We have options in all sectors to at least halve emissions by 2030
According to IPCC Working Group III Co-Chair Priyadarshi Shukla: “Having the right policies, infrastructure and technology in place to enable changes to our lifestyles and behaviour can result in a 40-70% reduction in greenhouse gas emissions by 2050.”
Adaptation strategies are necessary to reduce the impacts of climate change, such as increasing the resilience of infrastructure and communities, improving access to clean water and sanitation, and improving coastal infrastructure to protect low-lying areas from sea level rise. Additionally, mitigation strategies are needed to reduce greenhouse gas emissions, such as transitioning to renewable energy sources, implementing carbon pricing, and scaling up carbon capture technologies. The IPCC also discusses that many countries have already implemented carbon pricing systems within their borders. 57 nations around the world have implemented or scheduled implementation of carbon pricing initiatives that cover 11 gigatons of carbon dioxide, which is estimated to be around 20% of global greenhouse gas emissions. Carbon prices in these initiatives range from $1 to $127/ton of carbon dioxide, and the majority of emissions covered are priced at more than $10/ton.
Expansion of carbon pricing schemes. So far, 46 countries are pricing emissions through carbon taxes or emissions trading schemes (ETS) and others are considering it. Image: IMF.
8. International cooperation is required to tackle climate change
International cooperation and actions are necessary to tackle climate change, as climate change is a global problem that requires global solutions. This includes strengthening existing international agreements, such as the Paris Climate Accord, and developing new initiatives and policies to reduce greenhouse gas emissions. Additionally, countries must work together to provide support and assistance to vulnerable communities, such as those affected by extreme weather events and sea level rise.
As mentioned repeatedly in the IPCC AR6, limiting global temperature rise to 1.5C is still possible, though immediate action is needed. We must peak global greenhouse gas emissions before 2025, nearly halve emissions by 2030, and reach net-zero emissions around mid-century. Additionally, all stakeholders, including governments, the private sector, civil society and individuals, must take action to help reduce the intensifying risks of climate change and provide resources to communities affected by its impacts. We have a limited window of opportunity, and the time to act is now.
The UNFCCC has been successful in gathering near-universal participation, leading to the development of climate-related policies and targets on both national and sub-national levels. These policies, known as Nationally Determined Contributions (NDCs), require countries to outline their ambitions in terms of climate action and support, as well as increasing transparency of these initiatives.
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