A reduction in the growth rate of global greenhouse gas emissions provides a short window of opportunity to limit the maximum temperature increase to 1.5°C (2.7°F) by 2025, and avoid the more catastrophic effects of climate change, scientists have stated in the latest Intergovernmental Panel on Climate Change (IPCC) report.
This was one of the major messages from the Summary for Policymakers of the IPCC Working Group III report, Climate Change 2022: Mitigation of climate change, approved on April 4 by 195 member governments of the IPCC. It is the third installment of the IPCC’s Sixth Assessment Report (AR6), which will be completed this year.
The report noted that although the average annual global greenhouse gas emissions were at their highest levels in human history during the 2010-2019 period, the rate of growth has since slowed due to climate action. Immediate and deep emissions reductions across all sectors can help contain global warming within the limit of a 1.5°C increase from pre-industrial times.
“We are at a crossroads. The decisions we make now can secure a livable future. We have the tools and know-how required to limit warming,” said IPCC Chair Hoesung Lee. “There are policies, regulations, and market instruments that are proving effective. If these are scaled up and applied more widely and equitably, they can support deep emissions reductions and stimulate innovation.”
Some of the effective practices to reduce greenhouse gas emissions include a substantial reduction in fossil fuel use, widespread electrification, improved energy efficiency, and the use of alternative fuels (such as hydrogen). Creating compact and walkable cities, electrifying transport in combination with low-emission energy sources, and enhancing carbon uptake and storage using nature can also lower greenhouse gas emissions.
Other climate actions include reducing industry emissions – which account for a quarter of total emissions -- by reducing waste and increasing the efficient use of materials. Low- to zero-greenhouse gas production processes for basic materials like steel and chemicals are at their pilot to near-commercial stage and should contribute to overall industry sustainability in the future.
“Having the right policies, infrastructure, and technology in place to enable changes to our lifestyles and behavior can result in a 40-70% reduction in greenhouse gas emissions by 2050. This offers significant untapped potential,” said IPCC Working Group III Co-Chair Priyadarshi Shukla.
According to the IPCC, achieving the warming limit requires global greenhouse gas emissions to peak before 2025 at the latest, and be reduced by 43% by 2030. It also requires methane to be reduced by about a third.
“It’s now or never if we want to limit global warming to 1.5°C (2.7°F) … Without immediate and deep emissions reductions across all sectors, it will be impossible,” said IPCC Working Group III Co-Chair Jim Skea.
The global temperature will stabilize when carbon dioxide emissions reach net zero. For a 1.5°C (2.7°F) increase, this means achieving net-zero carbon dioxide emissions globally in the early 2050s; for a 2°C (3.6°F) increase, it is in the early 2070s. This assessment shows that limiting warming to around 2°C (3.6°F) still requires global greenhouse gas emissions to peak before 2025 at the latest, and be reduced by a quarter by 2030.
“Climate change is the result of more than a century of unsustainable energy and land use, lifestyles and patterns of consumption and production … This report shows how taking action now can move us towards a fairer, more sustainable world,” Skea said.