22 May 2008


The Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate
Change (IPCC) concludes that in order to stabiles climate change at 2 – 2.4 C, global
greenhouse gas emissions will need to be reduced by 50 – 85% as compared 2000 levels by
2050. The report also concludes that while this task is Herculean, it is achievable if a
portfolio of technologies that are currently available and those that are expected to be
commercialised in the coming decades are deployed. The report refers to energy efficiency
as playing a key role across many scenarios for most regions and timescales. In the shortand
mid-term, conservation and efficiency play the most important role among the examined
option categories (renewable energy, nuclear power, carbon capture and storage, fossil fuel
switch and forest sinks) to reduce CO2 emissions. From a sectoral perspective, the highest
cost-effective and low-cost potentials for mitigating GHG emissions arise from the buildings
sector. Based on bottom-up studies, this sector encompasses over one-third of the entire
mitigation potential at 0 cost of carbon. In economies in transition, the cost-effective potential
in the buildings sector is larger than in all other sectors combined. Capturing the costeffective
potential in buildings alone by 2030 can supply app. 38% of all mitigation needs to
hold emissions on a scenario that caps climate change at 3C. In addition to their
attractiveness from the perspective of cost-efficiency, energy conservation options are also
associated with substantial co-benefits, including improved energy security, reduced
mortality and morbidity, net employment benefits, improved competitiveness and new
business opportunities. However, while the cost-effective and low-cost potential for GHG
mitigation through energy efficiency is large, there are strong and numerous market barriers
that prevent them to be captured on a market basis. Therefore, the unlocking of this low-cost
potential requires a strong political commitment towards improved efficiency through the
mobilization of policies. The report demonstrates that there is a broad portfolio of such
policies is available and employed to kick-start and catalise markets to adopt energy-efficient
technologies. Many of them have been demonstrated to save energy at negative costs, i.e. at
net benefits to society, often at double- to triple-digit cost figures (i.e. under -10 or -100
USD/tonCO2), in many world regions.