Published online by Cambridge University Press: 05 March 2014
Part III of the Review considers the economic challenges of achieving stabilisation of greenhouse gases in the atmosphere.
‘Business as usual’ emissions will take greenhouse gas concentrations and global temperatures way beyond the range of human experience. In the absence of action, the stock of greenhouse gases in the atmosphere could more than treble by the end of the century.
Stabilisation of concentrations will require deep emissions cuts of at least 25% by 2050, and ultimately to less than one-fifth of today's levels. The costs of achieving this will depend on a number of factors, particularly progress in bringing down the costs of technologies. Overall costs, with sensible policies, are estimated at around 1% of GDP for stabilisation levels between 500–550 ppm CO2e.
The costs will not be evenly felt – some carbon-intensive sectors will suffer, while for others, climate change policy will create opportunities. Climate change policies may also have wider benefits where they can be designed in a way that also meets other goals.
Comparing the costs and benefits of action clearly shows that the benefits of strong, early action on climate change outweigh the costs. The current evidence suggests aiming for stabilisation somewhere within the range 450–550 ppm CO2e. Ignoring climate change will eventually damage economic growth; tackling climate change is the pro-growth strategy.