With just hours left in 2024, its a sure shot that this year on its way out will be the warmest on recorda sad fact that seemed inevitable even back in January, when AN covered the news that 2023 was reported as the warmest year on record. Sustainability topics are top of mind for many architects and designers, and likely will be for the coming decades. AN regularly reports on stories related to climate change;these include coverage of natural disasters, how to preserve buildings in the wake of storms, the use of innovative building materials, and reducing carbon emissions.As we look ahead to 2025, the unpredictability of storms and the uncertainty of politics make sustainable materials, buildings, and initiatives vitally important. In the meantime, here are a few of the pertinent stories on sustainability AN published in 2024.Through Material Innovation Center, students learn the skills required to successfully deconstruct a building in a way that preserves building materials for new use in future projects. (Courtesy Material Innovation Center/San Antonio Office of Historic Preservation)Three designer-led initiatives making the circular economy a realityTheres a lot of talk about the circular economy, especially in terms of construction. In our September issue, with a Focus section that highlighted sustainability, Jes Deaver introduced us to three designer-led initiatives making circular economies a reality.In Texas, the Material Innovation Center receives and redistributes donated building materials for affordable housing and community impact projects. It provides trades education and is setting up a community tool library. On the technology side of construction, the Circular Construction Lab (CCL) is a CAD extension that gives students and practicing architects a tool to measure circularity in early design phases. And Brooklyn-based firm Assemblage has adapted a circular systems approach to design and activism.Architects are designing a new type of science education facility to study our warming planetWith climate research comes a new building typology: the climate center. Diana Budds wrote about the education spaces that range in use from academic centers to nonprofit research institutions and public interpretive exhibition spacesall with the common mission: to help save the planet. Examples include Klimatorium, located in the coastal Danish city of Lemvig, designed by 3XN; the Jones Beach Energy and Nature Center on Long Island, New York, designed by nARCHITECTS; and the Resnick Sustainability Center on CalTechs Pasadena campus from CannonDesign.Its possible to construct sustainable multifamily housing with raw earth technology. (Courtesy Kaminsky Arkitektur)Raw earth is a sustainable material making its way into the U.S. marketNo discussion of sustainability would be complete without bringing up materials. Theres a lot of talk out there about alternatives to plastics and carbon-intensive materials like concrete. One material that is reemerging, if you will, is raw earth. Examples of it include adobe, rammed earth, compressed-earth blocks, and clay plaster. Michele Barbato, professor of structural engineering and structural mechanics at UC Davis, said before the material and method can truly proliferate: There has to be education, and right now, earthen construction is fundamentally not known. U.S. Department of Energy issued a national definition of a zero-emissions buildingWhat constitutes a net-zero building? This year the U.S. Department of Energy (DOE) issued a new national definition that outlines what qualifies as a net-zero structure. It is one thats highly energy efficient, does not emit greenhouse gases directly from energy use, and is powered solely by clean energy. Numerically speaking, it must obtain an ENERGY STAR score of 75 or higher and its greenhouse gas emissions must equal zero, some exceptions apply.The green roofs, Mayor Wu said, are meant to help provide shade, improve air quality, add new green space, and increase stormwater retention. (Courtesy City of Boston)Boston bus shelters got green roofsThe key to combating climate change is multipronged. While architects and buildings have a stake in it, so do our cities and the means we rely on to get around them. In Boston, a green initiative, also highlighted in our transportation roundup, between Social Impact Collective and the Mayors office trialled a program that put green roofs atop bus shelters. The vegetation-rich designs provide shade, improve air quality, add new green space, and increase stormwater retention.Women of Carbon documents the relationship between motherhood and climate changeA film screened during New York City climate week, Women of Carbon, profiled women scientists, architects, and engineers working in the carbon industry to advance a better future for the next generation. The initiatives documented in the film include manufacturing an electrical chemical system for making cement and an embodied carbon calculator.Midway Contemporary Art in Minneapolis reuses a two-story warehouse built in 1963. (Caylon Hackwith/Courtesy Midway Contemporary Art)b+ and Snow Kreilich Architects reuse building materials for a project in MinneapolisReusing a building is one way to reduce carbon emissions, and many architects have caught on to that. An example from 2024 that stood out was a hub designed for Midway Contemporary Arts operations inside an old warehouse building in Minneapolis. The project from b+ and Snow Kreilich Architects exemplifies intelligent ruinsthe idea of buildings can be built to anticipate future change, decay, and the flexibility for reuse. Spancrete panels were removed throughout the building to open up the space more, instead of disposing of them the architects opted to keep them for the second-phase library expansion, an act that conserves 40,000 pounds of embodied CO.