The consequences of climate change and the proposed mitigation policies raise the question of their economic impact. A significant global warming would be costly for the global economy and the cost-benefit balance in the fight against climate change favours action. Indeed, mitigation policies remain neutral for economic growth and may even encourage its development. Stimulating activity and creating decent jobs through a 'low carbon' transition is therefore a major challenge for the coming years. However, while stimulating economic activity is necessary, it is not sufficient to meet successfully the employment challenge of this transition. The challenge is also to support the evolution of professions weakened by divestment in sectors which consume the most non-renewable resources, towards those in developing sectors. Providing this support first means identifying the needs, in terms of jobs, skills, qualification and training, which will arise with the implementation of the "low carbon" transition.