Net Zero by 2050: A roadmap for the Global Energy Sector

Pathway to critical and formidable goal of net-zero emissions by 2050 is narrow but brings huge benefits, according to IEA special report.

21 May 2021

Summary for policymakers:

Policies should limit or provide disincentives for the use of certain fuels and technologies, such as […] gas boilers.
We estimate that around 55% of the cumulative emissions reductions in the pathway are linked to consumer choices such as purchasing an EV, retrofitting a house with energy-efficient technologies or installing a heat pump.
In buildings, bans on new fossil fuel boilers need to start being introduced globally in 2025, driving up sales of electric heat pumps.

Main report:

In buildings, emissions drop by 40% by 2030 and more than 95% to 2050. By 2030, around 20% of the existing building stock worldwide is retrofitted and all new buildings comply with zero-carbon-ready building standards. There are no new fossil fuel boilers sold from 2025, except where they are compatible with hydrogen, and sales of heat pumps soar. Natural gas use for heating drops by 98% in the period to 2050.
Energy efficiency and electrification are the two main drivers of decarbonization of the buildings sector in the NZE. That transformation relies primarily on technologies already available on the market, including improved envelopes for new and existing buildings, heat pumps, energy-efficient appliances and bioclimatic and material-efficient building design.
The NZE pathway for the buildings sector requires a step change improvement in the energy efficiency and flexibility of the stock and a complete shift away from fossil fuels. To achieve this, more than 85% of buildings need to comply with zero-carbon-ready building energy codes by 2050. This means that mandatory zero-carbon-ready building energy codes for all new buildings need to be introduced in all regions by 2030, and that retrofits need to be carried out in most existing buildings by 2050 to enable them to meet zero-carbon-ready building energy codes.
- A zero-carbon-ready building is highly energy efficient and either uses renewable energy directly, or uses an energy supply that will be fully decarbonized by 2050, such as electricity or district heat. Zero-carbon-ready building energy codes should cover building operations as well as emissions from the manufacturing of building construction materials and components (and also target net-zero emissions from material use in buildings)
Retrofit rates increase from less than 1% per year today to about 2.5% per year by 2030 in advanced economies. To achieve savings at the lowest cost and to minimize disruption, retrofits need to be comprehensive and one-off.
Building envelope improvements in zero-carbon-ready retrofit and new buildings account for the majority of heating and cooling energy intensity reductions in the NZE, but heating and cooling technology also makes a significant contribution. Space heating is transformed in the NZE, with homes heated by natural gas falling from nearly 30% of the total today to less than 0.5% in 2050, while homes using electricity for heating rise from nearly 20% of the total today to 35% in 2030 and about 55% in 2050. High efficiency electric heat pumps become the primary technology choice for space heating in the NZE, with worldwide heat pump installations per month rising from 1.5 million today to around 5 million by 2030 and 10 million by 2050. [By 2050, the global stock of heat pumps will reach 1.8 billion.] Hybrid heat pumps are also used in some of the coldest climates, but meet not more than 5% of heating demand in 2050.
There are no new coal and oil boilers sold globally from 2025 in the NZE. Sales of gas boilers fall by more than 40% from current levels by 2030 and by 90% by 2050. By 2025 in the NZE, any gas boilers that are sold are capable of burning 100% hydrogen and therefore are zero-carbon ready.
Near-term government action is needed to ensure that zero-carbon-ready buildings become the new norm across the world before 2030 for both new construction and retrofits.
Governments need to establish policies for coal and oil boilers and furnaces for space and water heating, which in the NZE are no longer available for sale from 2025. They also need to take action to ensure that new gas boilers are able to operate with low-carbon gases (hydrogen ready) in decarbonized gas networks. Which alternatives are best will depend to some extent on local conditions, but electrification will be the most energy-efficient and cost-effective low-carbon option in most cases, and decarbonizing and expanding district energy networks is likely to make sense where densities allow.

Read the report “Net Zero by 2030” by IEA