Fossil fuels' continued relevance in a world limited to a 2°C temperature rise – the UN's vision for global carbon policy – critically depends on CCS (Carbon Capture & Storage). It is the only technology that can decarbonise fossil fuels. But implementing CCS has been dramatically slowed by its high cost, lack of policy clarity, and as attention is diverted to renewables. Even so, energy companies are urging the importance of CCS when pressed about carbon and their investments. While the energy industry is coming under increasing pressure in the run up to the UN Climate Conference, no one expects to see a deal agreed to limit global emissions to a 2°C temperature rise. But many anticipate the conference will lay the groundwork for this ultimate target. So then, the big question for energy companies is where to place their bets on future investments? Wood Mackenzie looks at the opportunities and challenges ahead for CCS, and why the technology is stuck between a rock and a hard place.