A major obstacle to addressing the climate challenge is the daunting scale of potential solutions. In essence, reducing emissions to safe levels means transforming the way we use energy, whether in power, transport, or heating and cooling, as well as many important industrial processes. The lack of any obvious candidate to replace fossil fuels across this range of human activity makes serious emission reductions appear prohibitively difficult.

The search for a single "silver bullet" solution is misguided, however. A number of options exist for reducing emissions by managing energy demand and employing low-carbon energy supplies and technologies that can make major contributions to clean economic growth. A recent paper by Princeton researchers Rob Socolow and Stephen Pacala demonstrated this point graphically by breaking the required emission reductions down into manageable (though still large) wedges, each provided by a different technology or set of technologies. These wedges include options such as:

• Biofuels from cellulose, grain, or vegetable oils
• Carbon capture and geologic storage
• Efficiency in transportation and power generation
• Wind energy
• Fuel-switching from coal to natural gas

Owing to its solution-oriented framework, the wedges approach has captured the imagination of those eager to tackle climate change. It also raises important questions. Most importantly, what are the needs in terms of technology, capital, market actors, and regulatory environment? What is the balance between in-country policy and international mechanisms in bringing these wedges to market? What do policy makers and capital markets need to know to enable them to deploy clean technologies at the stupendous rate needed? And how can we manage the synergies and potential conflicts between wedges?

Source: Pacala and Socolow, Science Magazine, 2004. Each wedge represents 1 gigatonne of carbon emissions. Seven wedges are needed to stabilize global emissions at current levels by 2050. Because of the likely increase in demand, additional efforts would be needed beyond 2050 to stabilize concentrations. Pacala and Socolow identify 15 wedge options in their analysis.

Bringing Wedges to Market

WRI is analyzing the viability of bringing the various technology options presented in the wedges analysis to market. Specifically, to establish the GHG reduction benefits of scaling up individual wedges, WRI is examining:

• The market potential for each technology, as well as political and financial barriers to accelerating the adoption of these technological options,
  
  
• The government policies and economies of scale needed to allow clean technologies to break through and be rapidly deployed, and
  
  
• The relative competitive positioning of different companies to deliver these technologies to market.

The goal of the analysis is to accelerate the government policy, corporate action, and financial investment decisions consistent with global technology diffusion for averting dangerous climate change.

WRI is working with its broad network of corporate partners to inform the research, which will deliver optimal policy designs to promote technology leaders and send powerful market signals to other industry players who are lagging behind. As well, this work draws on expertise in other WRI projects, such as the CCS project, EMBARQ, the Green Power Market Development Group, and the Biofuels project.