Wind energy has some upfront carbon costs that most people don't consider. There's the carbon cost of mining the materials to build the wind turbines, especially the rare earth materials required by the generators and electronics.
Then there's the carbon cost of building and transporting the huge blades (some are almost 300 feet long) to the construction sites. Each turbine has three blades. Each blade is transported by a truck and trailer. That's three trips from the manufacturing facility to each construction site. The typical trip crosses two or more states.
Heavy equipment is needed at the construction sites. Each turbine's tower must be taller than the blade length, so a suitable (heavy) crane is needed. Each turbine's base is a huge slab of poured concrete that's about 14 to 16-feet in diameter and 25-feet to 35-feet deep). So, concrete needs to be delivered to each turbine site. Roads need to be built at each site to handle these loads.
Nuclear power also has carbon costs during the construction phase but there's only one construction site, not many as with wind farms. A nuclear power plant connects to the region's power grid at a single point. With wind power, a powerline network must be built to collect the power from all the turbines in a wind farm.
The carbon costs of mining uranium appears not to be significantly more costly than mining the rare earth materials needed for all of these technologies, especially for solar. There's also the capability of using thorium in reactors instead of uranium. Thorium is relatively plentiful—it's uncovered in the process of mining other minerals..