A decade to act

On April 4, 2022, the third chapter of the Sixth Assessment Report, to be completed this year, was approved by the 195 member governments of the IPCC. The first volume, published in August 2021, examined the physical science of the climate system and unequivocally attributed climate change to human actions. The second, published in February 2022, focused on the impacts of climate change and how to adapt and found that half of the world's population is highly vulnerable to the effects of warming temperatures. This third part focuses on climate change mitigation and solutions to reduce emissions.

The report makes one key point clear: there are cost-effective ways to reduce emissions, we know what to do and we have the tools to do it. Yet while we are aware of the strides that have been made, climate policies are still too loose to achieve the key goal of limiting global temperature rise to 1.5°C, as set out in the Paris Agreement. A growing set of policies and laws has improved energy efficiency, reduced deforestation rates, accelerated the deployment of renewable energy, the use of hydrogen and sustainable biofuels, and developed carbon capture and storage technologies. The costs of solar and wind energy fell by 85% and 55% respectively between 2010 and 2019, making them very affordable and enabling their increasing large-scale use. The report also announces that "digitization," as intense as robotics and artificial intelligence, innovation, technology development and transfer, guided by well-designed policies, are effective ways to increase energy efficiency and manage renewable energy.

Then there is a chapter on cross-sectoral mitigation options; it is stated that all sectors must contribute to decarbonization, although the potential for emission reductions varies for each. In terms of reducing emissions in industry, a sector responsible for about a quarter of global emissions, more efficient use of materials, reuse and recycling of products, minimizing waste, use of low-emission energy, and new production processes will be needed. The agriculture and forestry sectors can also provide large-scale emission reductions, especially through carbon dioxide removal and storage processes. In the scenarios the IPCC has assessed, limiting global warming to about 1.5°C requires that global greenhouse gas emissions peak by 2025 at the latest and be reduced by 43% by 2030, at the same time, methane would also need to be reduced by about one-third. Global temperature will stabilize when carbon dioxide emissions reach net zero in 2050, a goal toward which nations are working.

This report also introduces several new components. There is a chapter on the social aspects of mitigation, which explores the "demand side," i.e., what drives the consumption of greenhouse gas emissions, and complements the chapters that analyse the "supply side" of climate change, i.e., what produces the emissions. In fact, for the first time in an IPCC study, scientists have looked at demand-side emission reductions, openly stating that individual behaviour matters, that behavioural and cultural changes carried out on an individual and collective scale globally can reduce emissions by 40-70% from recent trends. Meat consumption, air travel, and different energy use in buildings are all areas where the combined decisions of many people can have a substantial impact. Cities and urban areas also offer significant opportunities for emission reductions. These can be achieved through lower energy consumption especially in transportation, mobility, construction, and home heating, and increased carbon absorption and storage through the creation of green areas.

Decarbonization must then also be supported financially.

The report shows that although financial flows are below the levels needed to limit global warming to within 1.5°C, there is sufficient global capital and liquidity to fill investment gaps. However, there needs to be a clear signal from governments and the international community that they are willing to ensure greater alignment of policies and funding, which can not only reduce environmental impacts, but can also increase employment, business opportunities, health and equity. The IPCC concludes its report by stating that effective and equitable climate governance is critical to sustainable development and requires the commitment of business, citizens, and policy actors.

"Climate change is the result of more than a century of unsustainable energy and land use, lifestyles, and consumption and production patterns," said Jim Skea, co-chair of the IPCC Working Group that produced this report. "Action in this decade is critical." So, expect the fourth and final part of the Report next fall, before COP 27 to be held this year in Egypt's Sharm El-Sheikh in November.