ArcelorMittal, the world’s largest steelmaker, recently introduced a program to offer certificates to customers that certify they have reduced their carbon footprint through the steelmaker’s own greenhouse-gas emission reductions.

Cpnstruction disruptions now are seen, including component shipments to North America, delays on China Belt and Road megaproject, halted industry travel in Europe and respirator mask shortages.

When President Trump said on March 1 that he would impose tariffs of 25% on foreign steel and 10% on aluminum, it immediately put construction estimators and executives, and the suppliers they rely on, into a holding pattern.

Trump must decide by mid-April whether to adopt Commerce Dept.'s proposed stiff penalties.