Simulating the deep decarbonisation of residential heating for limiting global warming to 1.5 °C

Abstract

Whole-economy scenarios for limiting global warming to 1.5°C suggest that direct carbon emissions in the buildings sector should decrease to almost zero by 2050, but leave unanswered the question how this could be achieved by real-world policies. We simulate which policy measures could induce an almost complete decarbonisation of residential heating, the by far largest source of direct emissions in residential buildings. Under which assumptions is it possible, and how long would it take? We use the non-equilibrium bottom-up model FTT:Heat to simulate policies for a transition towards low-carbon heating in a context of inertia and bounded rationality, focusing on the uptake of heating systems. Our results indicate that the near-zero decarbonisation is achievable by 2050, but requires substantial policy efforts. We find that policy mixes are more effective for incentivising the uptake of fuelefficient low-carbon technologies, compared to a residential carbon tax as the only policy. In combination with subsidies and procurement policies for renewables, near-complete decarbonisation could be achieved with a tax of 50-200 €/tCO 2. Without being complimented by additional policies, carbon taxes show a decreasing marginal impact on total emission reductions, thus remaining insufficient for deep decarbonisation. In all scenarios, the decarbonisation of heating would increase projected heating costs faced by households initially, but could lead to cost reductions in most world regions in the medium term. We show that the potential impacts of policies highly depend on behavioural decisionmaking by households, especially in a context of deep decarbonisation and rapid transformation.

Demand-side approaches for limiting global warming to 1.5 °C

“…Despite these far-reaching changes, the authors stress that their projected increases in solar and geothermal energy are still lower than indicative national targets. Knobloch et al (2018) also stress the links between demand and supply. For instance, improved building shells combined with solar thermal and ground source heat pumps are shown to considerably reduce electricity demand (by up to 50% in certain scenarios).…”

“…Likewise, Gota et al (2018) stress that current mitigation measures rely heavily on assumptions of behavioral change. Knobloch et al (2018) find that the potential impacts of modeled policy instruments are highly dependent on assumptions of behavioral decision-making (cf. Kolstad et al 2014;Mundaca et al 2010;Worrell et al 2004).…”

“…Modeling deep decarbonization pathways in the residential heating sector, Knobloch et al (2018) use a sectoral carbon tax to drive mitigation measures. In this case, a carbon tax increases the price of fossil fuels relative to their carbon content.…”

“…Wilhite and Norgard 2004). Knobloch et al (2018) explore policy mixes and their interactions. Carbon taxes, technology subsidies, a procurement scheme, and building codes are explored in a variety of scenarios.…”

“…Assuming stringent building codes, shell-thermal efficiencies in single-family homes, apartments, and mobile homes also play a key role in emission reductions consistent with the 1.5°C goal. Knobloch et al (2018) focus on deep decarbonization pathways for residential heating. Their results show that near-zero decarbonization in 2050 is feasible, provided that stringent, integrated policy frameworks are put in place.…”