"The cement sector needs to drastically reduce its contribution to climate change, delaying or avoiding this challenge is not an option," Stephanie Pfeifer, CEO of IIGCC, said in a statement. "This is, ultimately, a critical issue for the business for the sector."
The demands have been sent to the chairmen of the boards in each of the four companies. The letters are signed by investors, including BNP Paribas Asset Management and Aberdeen Standard Investments.
Companies that do not move quickly to change their practices run the risk of losing access to capital, according to investors. Without a clear single path to decarbonisation, they recommend that companies look for a range of options.
Cement manufacturers must "anticipate the profound transformation facing their sector by addressing the barriers to decarbonization in the short and medium term," said Pfeifer.
Investors said that Heidelberg Cement, a German multinational, has already committed to some key reforms.
The Swiss company Lafarge Holcim said in a statement that "it is aware of the carbon footprint of cement and concrete and that we are at the forefront of mitigating climate change." He said he was exploring new technologies to reduce their carbon use.
Heidelberg Cement, CRH and Saint-Gobain did not respond to requests for comments.