The World is at the beginning of a transition in energy use. The challenge we face in terms of energy and climate change is unprecedented, as the global population heads towards 9.5 billion by 2060 and hundreds of millions of people move out of poverty in the emerging economies. Demand for energy could rise by up to 80% by around 2050, increasing global greenhouse gas emissions. All sources of energy will be needed, i.e. oil, gas, coal, bio, wind, solar, nuclear etc. Alternatives such as renewables and nuclear, will grow and represent more of the energy mix in the future. However, even with strong government support, it takes time for newer energy technologies to become affordable and available at scale. According to Shell's scenarios, energy from solar, wind, hydro-electricity and biomass could rise to around 30% by 2050, with strong government support. Nuclear power will also continue to play a part. Unprecedented efficiency improvements could also be unlocked with strong government support. However, fossil fuels are expected to continue to dominate and to meet around 65% of energy demand by mid-century. The total amount of CO2 emitted over time needs to be addressed, rather than focus just on emissions in a given year. It is this total quantity of CO2 emitted into the atmosphere that drives climate change. The climate issue can be described as a "stock" issue -- unrelated to the flow of emissions into the atmosphere at any point in time (e.g. 2050), but dependent on the cumulative stock of emissions that mankind will put into the atmosphere. CO2 sticks around unlike many other emissions to atmosphere which don't accumulate; they disperse, break down or drop out very rapidly. The continued dominance of fossil fuel use through to the middle of the century, means carbon dioxide levels in the atmosphere will continue to rise unless emissions are returned to their source. CCS has the potential to address CO2 emissions on a scale equal to its production and at a cost that appears more than manageable by society. The IEA has reported that CCS could provide one fifth of the CO2 emissions mitigation effort needed by 2050, but would require just 6% of the overall investment needed to achieve a 50% reduction in GHG emissions in 2050. Without CCS, overall costs to halve global emissions by 2050 rise by 70%.