A report of the Intergovernmental Panel on Climate Change (IPCC), released on Monday, has called for “immediate and deep emission reductions across all sectors” in order to limit the rise in global warming to 1.5 degrees above pre-industrial levels (1850-1900).

The report was that of the Working Group III — dealing with ‘mitigation’ — refers to measures to be taken to prevent further global warming. The previous reports of Working Groups I and II — released last year and earlier this year — dealt with ‘physical science basis’ for climate action and ‘adaptation’, referring to the measures that are to be taken to cope up with inevitable climate change effects.

These three form part of IPCC’s 6 th Assessment Report, or the 6 th round of assessment; the 5 th came in 2013.

“Without immediate and deep emissions reductions across all sectors, limiting global warming to 1.5 degrees is beyond reach,” the report released today said.

Emission cuts

Stressing on the urgency of emission reductions, the report noted that to meet the 1.5 degrees target, net CO2 emissions should be zero by the early 2050s. Even if the target is only 2 degrees C, global greenhouse gas emissions should not rise after 2025 (they must start falling) at the latest, and must be reduced by a quarter by 2030.

It is not as though there has been no action. The report notes that 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.”

However, there is a need to do more. “We have options in all sectors to at least halve emissions by 2030 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),” says IPCC Chair Hoesung Lee.

Emission reductions are possible in areas like energy, mobility, buildings and cities, and agriculture, the report notes. “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.”

Zero-carbon buildings

Like cities, buildings offer a big potential to cut emissions. “We see examples of zero energy or zero-carbon buildings in almost all climates,” says IPCC Working Group III Co-Chair Jim Skea. “Action in this decade is critical to capture the mitigation potential of buildings.”

This involves 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.

The report stresses that cutting emissions need not be painful; it indeed can be the beneficial. Some response options can absorb and store carbon and, at the same time, help communities limit the impacts associated with climate change. For example, in cities, networks of parks and open spaces, wetlands and urban agriculture can reduce flood risk and reduce heat-island effects.

Similarly, mitigation in industry can reduce environmental impact and increase employment and business opportunities. Electrification with renewables and shifts in public transport can enhance health, employment and equity. “Climate change is the result of more than a century of unsustainable energy and land use, lifestyles and patterns of consumption and production,” the report says.