An engineering perspective on climate change: Mitigation or adaptation?

• 2°C variation in atmospheric air is thermally equivalent to 0,002°C variation in seawater temperature • The Earth climate overall thermal time constant is estimated in 67±3,7 years • CO 2 emissions are increasing since 20 years, driving a vegetation greening phase • Engineering attention should be more devoted to adaptation solutions rather than mitigation actions. Most of the Nations are currently undergoing a deep transformation of the existing energy, water and production infrastructure, including both power and heat generation as well as mobility systems, targeting a global decarbonization and reduction of fossil fuel utilization, fostering the adoption of renewable energy sources coupled to energy storage solutions. Such strategies are mainly based on climate change assessment and predictions carried out by the Intergovernmental Panel on Climate Change (IPCC), which require a wide-spectrum of actions on most of society activities and use of resources (fuels, water, food, materials). However, the scientific basis of such strategies, related to climate change modelling, are subject to uncertainty, like any quantitative analysis. In this article, a common engineering approach to time-dependent thermal modelling and publicly available datasets are employed for a twofold objective: first, trying to resume the overall reliability that can be expected on climate change modelling at global scale in the long-run, and, second, resuming the current status of CO 2 emissions linked to fossil fuel exploitation and future reserves. Results stress the current need of deep ocean water temperature data with sufficient accuracy for surface climate predictions, given the seawater thermal capacitance, which is higher by three orders of magnitude than the gaseous atmospheric thermal capacitance. The engineering-based Earth thermal response model presented here allowed to estimate the climate time constant in ∼67 years for long-term transients. Such evidence coupled with the observation of the large fossil fuel availability, brought to the pragmatic conclusion that worldwide efforts should be mainly devoted to climate change adaptation actions, rather than mitigation actions, with founded belief that the future climate change, in terms of global temperature increase, might be less severe than generally recognized, and that higher atmospheric CO 2 concentrations will keep sustaining the increased vegetation growth, with social benefits partially compensating the climate change impacts.