With the exception of the Fairless Hills and Gary facilities, the lawsuits concern facilities acquired by U.S. Steel via its 2003 purchase of National Steel Corporation, not its historic facilities. In 2021, U. S. Steel announced a goal to target net-zero carbon emissions by 2050. The company previously set a target to reduce greenhouse gas emissions intensity by 20% by 2030. Legacy U.S. Steel Tower The U.S. Steel Tower in Pittsburgh, Pennsylvania, is named after the company and since 1970, the company's corporate headquarters have been located there. It is the tallest skyscraper in the downtown Pittsburgh skyline, built out of the company's Corten Steel. New York City's One Liberty Plaza was also built by the corporation as that city's U.S. Steel Tower in 1973. Steelmark logo When the Steelmark logo was created, U.S. Steel attached the following meaning to it: "Steel lightens your work, brightens your leisure and widens your world." The logo was used as part of a major marketing campaign to educate consumers about how important steel is in people's daily lives. The Steelmark logo was used in print, radio and television ads as well as on labels for all steel products, from steel tanks to tricycles to filing cabinets. In the 1960s, U.S. Steel turned over the Steelmark program to the AISI, where it came to represent the steel industry as a whole. During the 1970s, the logo's meaning was extended to include the three materials used to produce steel: yellow for coal, orange for ore and blue for steel scrap. In the late 1980s, when the AISI founded the Steel Recycling Institute (SRI), the logo took on a new life reminiscent of its 1950s meaning. The Pittsburgh Steelers professional football team borrowed elements of its logo, a circle containing three hypocycloids, from the Steelmark logo belonging to the American Iron and Steel Institute (AISI) and created by U.S. Steel. In the 1950s, when helmet logos became popular, the Steelers added players' numbers to either side of their gold helmets. Later that decade, the numbers were removed and in 1962, Cleveland's Republic Steel suggested to the Steelers that they use the Steelmark as a helmet logo. U.S. Steel financed and constructed the Unisphere in Flushing Meadows-Corona Park, Queens, New York, for the 1964 World's Fair. It is the largest globe ever made and is one of the world's largest free-standing sculptures. Fabrication of Chicago Picasso sculpture