Limiting warming to 1.5°C tough sans deep emissions reduction: IPCC

Since 2010, there have been sustained decreases of up to 85 per cent in the costs of solar and wind energy and batteries. An increasing range of policies and laws have enhanced energy efficiency, reduced rates of deforestation and accelerated the deployment of renewable energy, the report noted.

“We are at a crossroads. The decisions we make now can secure a liveable future. We have the tools and know-how required to limit warming,” said IPCC chair Hoesung Lee. 

“I am encouraged by climate action being taken in many countries. 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,” he observed.

Options are available in all sectors to at least halve emissions by 2030, it said. The report is the third instalment of the IPCC’s Sixth Assessment Report (AR6), which will be completed this year.

Limiting global warming will require major transitions in the energy sector. This will involve a substantial reduction in fossil fuel use, widespread electrification, improved energy efficiency, and use of alternative fuels (such as hydrogen).

“Having the right policies, infrastructure and technology in place to enable changes to our lifestyles and behaviour can result in a 40-70 per cent reduction in greenhouse gas emissions by 2050. This offers significant untapped potential,” said IPCC Working Group III co-chair Priyadarshi Shukla.

Cities and other urban areas also offer significant opportunities for emissions reductions.  These can be achieved through lower energy consumption (such as by creating compact, walkable cities), electrification of transport in combination with low-emission energy sources, and enhanced carbon uptake and storage using nature. There are options for established, rapidly growing and new cities as well, the report said.

“We see examples of zero energy or zero-carbon buildings in almost all climates,” said IPCC Working Group III co-chair Jim Skea.

Reducing emissions in industry will involve using materials more efficiently, reusing and recycling products and minimising waste. For basic materials, including steel, building materials and chemicals, low- to zero-greenhouse gas production processes are at their pilot to near-commercial stage.

This sector accounts for about a quarter of global emissions. Achieving net zero will be challenging and will require new production processes, low and zero emissions electricity, hydrogen, and, where necessary, carbon capture and storage.

In the scenarios we assessed, limiting warming to around 1.5°C (2.7°F) requires global greenhouse gas emissions to peak before 2025 at the latest, and be reduced by 43 per cent by 2030; at the same time, methane would also need to be reduced by about a third.

The global temperature will stabilise when carbon dioxide emissions reach net zero. For 1.5°C (2.7°F), this means achieving net zero carbon dioxide emissions globally in the early 2050s; for 2°C (3.6°F), it is in the early 2070s, it noted. 

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, IPCC said in a press release.

The report looks beyond technologies and demonstrates that while financial flows are a factor of three to six times lower than levels needed by 2030 to limit warming to below 2°C (3.6°F), there is sufficient global capital and liquidity to close investment gaps.

However, it relies on clear signalling from governments and the international community, including a stronger alignment of public sector finance and policy.

The report strengthens the International Labour Organisation’s (ILO) call for economic strategies that support clean energy, foster resource-efficient economic growth, create income and decent jobs, and reduce poverty and inequality, ILO said in a statement.