Paradigm shifts of climate science for climate solutions

Climate science has been playing a central role in shaping the global consensus on climate actions. Given the immense complexity of the Earth's climate system, climate science has primarily concentrated on advancing scientific understanding of anthropogenic climate change while providing viable options for adaptation and mitigation policies to governments.1Intergovernmental Panel on Climate Change.https://www.ipcc.ch/reports/Date: 2007Google Scholar For instance, climate research on the uncertainties in climate sensitivity estimation, patterns of global warming, and the attributions of global temperature and precipitation changes has yielded many significant findings on fundamental problems, resulting in substantial and robust progress in climate science. Many of these advancements are encapsulated in a series of IPCC reports,1Intergovernmental Panel on Climate Change.https://www.ipcc.ch/reports/Date: 2007Google Scholar on which the global consensus on climate actions and solutions is based. Some may argue that the task of climate science in climate solutions is settled, and climate science is not as crucial as before. But this is not the case. On the contrary, here I will argue that climate science per se is an indispensable part of climate solutions, and the new era of climate actions does require certain necessary paradigm shifts of climate science so that it may contribute in a more direct way to global endeavors in climate adaptation and mitigation. While the climate solution has set its goal of limiting global warming to 2°, or preferably 1.5°C, this ambitious goal of mitigation is only achievable through coordinated actions involving energy systems, food systems, land use, building infrastructure, industrial production, and people's consumption styles across nations. Therefore, the mitigation goal is reasonably included as one of the Sustainable Development Goals2United NationsTransforming our world: The 2030 agenda for sustainable development.https://sdgs.un.org/2030agendaDate: 2015Google Scholar (SDGs; the 13th of SDGs, UN 2015), which is inherently interlinked with other SDGs. The mitigation goal should also be linked with human's adaptation to climate change. Taking developing nations and regions as an example, these areas are often in urgent need of economic and societal development, requiring more investment in energy system and transportation infrastructures. However, they are also most vulnerable to the impacts of climate change. As a result, the stresses of economic development, vulnerability to climate change, and lower educational levels are tightly intertwined in these nations and regions. Climate science, with its paradigm shifted, may play an essential role in solving such dilemmas that the developing world is facing, as will be detailed in the next section (Figure 1). The boundaries between the branches of climate science—namely, physical science basis, adaptation, and mitigation, as exemplified by the three working groups of the IPCC1Intergovernmental Panel on Climate Change.https://www.ipcc.ch/reports/Date: 2007Google Scholar—have been and will continue to be necessary. Nevertheless, these branches are not independent of each other. In a climate science oriented toward climate solutions, these boundaries should be transcended, and the linkages from adaptation to physical science and mitigation to physical science, along with the mutual adaptation-mitigation linkage, must be accentuated. The first two linkages—adaptation to physical science and mitigation to physical science—represent the feedbacks from adaptation and mitigation for the physical science basis to adjust its research agenda or refine its outputs. These feedbacks may manifest at local, regional, national, and global scales. In this context, the demands emanating from the adaptation and mitigation domains have the potential to reshape the scope and methodology of the physical science basis branch of climate science. The third linkage, the mutual adaptation-mitigation linkage, holds particular importance for the success of climate solutions, as it is crucial for achieving the goal of sustainable societal and economic development across vast underdeveloped yet climate-vulnerable nations and regions. For instance, if renewable energy infrastructure is implemented from the outset in these areas, then the subsequent establishment of associated transportation and education systems can serve as drivers for economic development. Consequently, the initial investment in renewable energy not only aligns with the global mitigation goal but also lays a solid foundation for the adaptation to climate change by enhancing the well-being of these underdeveloped nations and regions. This also underscores the extra benefit of early technological and financial transfers from the developed world to the developing world. Climate science may play an essential role in planning renewable energy infrastructures and providing daily to seasonal predictions of available wind and solar powers. Meanwhile, transcending the boundaries between the branches of climate science is also consistent with a paradigm shift from physical climate system science to earth system science (ESS), which considers the physical climate system and biosphere as an integrated whole by coupling the physical processes in the former and biogeochemical processes in the latter so that global carbon cycle can be considered together with physical climate change. In the era of climate solutions, novel methods for integrating physical climate modeling, earth system modeling, and risk assessment modeling are more than needed. For instance, research may be conducted to assess the potential impact of climate changes and adaptation and mitigation pathways on regional economic development, food and water security, health, biodiversity, and energy security.3Reid W.V. Chen D. Goldfarb L. et al.Earth System Science for Global Sustainability: Grand Challenges.Science. 2010; 330: 916-917https://doi.org/10.1126/science.1196263Crossref PubMed Scopus (430) Google Scholar Despite continuing and systematic progress, climate science still has drawbacks in serving climate actions and climate solutions. For instance, state-of-the-art climate models may overestimate the global-averaged climate sensitivity but underestimate the potential changes of extreme events. Furthermore, these models still lack the capability to robustly project the spatial patterns of climate change, which are essential for making correct choices in adaptation and mitigation pathways. Urgent climate actions cannot afford to wait for the emergence of a flawless climate model, which might take several decades or never materialize. Does this imply that climate science, including climate modeling, is incapable of directly contributing to climate solutions? The answer is no, climate science can directly contribute to climate solutions. Indeed, solution-focused climate science may bypass the aforementioned drawbacks by its synergy with technical innovations. Examples of this synergy between climate models with technical innovation include the following.(1)Combining global climate models with high-resolution numerical weather prediction (NWP) models or regional high-resolution climate models to estimate the potential changes in (and/or storylines of) extreme weather and climate events.(2)Integrating climate models with data-driven artificial intelligence (AI) methods to provide downscaled information useful for adaptation and mitigation at various spatiotemporal scales.(3)Developing next-generation high-resolution climate models with the innovations in computing technology, in AI technology, and in available big-data resources to disruptively improve the representation of physical, biological, and chemical processes in climate/Earth system models.4Schneider T. Behera S. Boccaletti G. et al.Harnessing AI and computing to advance climate modelling and prediction.Nat. Clim. Chang. 2023; 13: 887-889https://doi.org/10.1038/s41558-023-01769-3Crossref Scopus (11) Google Scholar These innovative methods may directly contribute to early warning systems of the disastrous impacts of climate change such as extreme events for local, regional, and national policymakers and the general public. Meanwhile, various types of climate and NWP models may also be directly employed in the implementation and operation of innovative renewable energy systems. This application contributes to daily and medium-range weather and electricity prediction for the renewable energy business. Last but not least, the paradigm shifts of climate science do not imply that curiosity-driven theoretical research in climate science will lose its ground. On the contrary, these shifts may well broaden the scope of fundamental climate science and ESS. Significant progress has been achieved in understanding equilibrium climate systems and their uncertainties over the past decades. However, the understanding of a non-equilibrium climate/Earth system remains at its infant stage. Curiosity-driven theoretical studies will find their way in the following scientific inquiries, among others.(1)When and how might an abrupt weakening or collapse in the Atlantic meridional overturning circulation occur?(2)What are the underlying dynamics controlling the tipping elements of the climate/Earth system?(3)What are the controlling factors for extreme climate and weather events and how might the extremes change in the future?(4)Can we develop a universal theory with sound mathematical and physical basis for climate/Earth systems as huge non-equilibrium complex systems? The theories and methods in traditional non-equilibrium statistical physics and complexity science may be helpful in the abovementioned inquiries but are far from being able to solve the problems. Disruptively new ideas and methods are urgently needed, and as such, research on the fundamental theories of a non-equilibrium climate/Earth system has the potential to contribute to advancements in mathematics, physics, and the science of complex systems.5The Nobel Committee for PhysicsScientific Background on the Nobel Prize in Physics 2021.https://www.nobelprize.org/uploads/2021/10/sciback_fy_en_21.pdfDate: 2021Google Scholar This work is supported by the National Natural Science Foundation of China (no. 42175070). The author declares no competing interests.