Low-carbon concrete, for example, can greatly reduce emissions that harm our climate. Introduced in the mid-20th century, low-carbon concrete incorporated alternative ingredients that decreased cement content while improving strength and durability. Homeowners can find low-carbon concrete in Maine if they know where to look. And while DIYers unfortunately won’t find bags of low-carbon concrete mix locally, the supplier Auburn Concrete, with locations in southern and central Maine, sells competitively priced ready mix for large projects. So go ahead and build that retaining wall out back using low-carbon concrete products — and if a job requires a professional, ask an experienced contractor to incorporate them.