Biogen, the biggest company in Mass., has gone carbon-neutral

Drug maker Biogen is based in Cambridge.Jonathan Wiggs/Globe Staff/Globe Staff

Global warming worriers have a reason to celebrate: Biogen, the most valuable company in Massachusetts, has cut its net carbon emissions to zero.

The Cambridge-based drugmaker said Tuesday that after a decade of curtailing its energy use and supporting renewable energy projects, it has balanced out the negative impact its business has on global warming with positive impacts. Several other major companies such as Microsoft have also aimed for carbon neutrality, but the move by the pharmaceutical giant is a big one for a Massachusetts business.

Everything from Biogen’s supply chain to the greenhouse gases discharged by employees’ cars was taken into account before the announcement, said Hector Rodriguez, the company’s director of environmental health, safety, and sustainability. Nearly 1 million tons of carbon dioxide emissions will be curtailed every year through the company’s efforts, Rodriguez said.

Biogen, which is valued at $98 billion, reached the goal by cutting back on waste, building more efficient structures, and buying renewable energy credits. Those credits represent units of electricity produced by things like solar panels and wind turbines, and the drugmaker buys and trades them to offset the fossil fuel emissions it can’t avoid.

“We have a footprint here in Cambridge of a few hundred thousand square feet. If we wanted to create our own source of renewable energy, it’s just a physical impossibility,” Rodriguez said. “When you think about it from a macro environmental perspective, it’s the same thing.”

He declined to provide the cost of the campaign, saying it could put the impact “out of context,” but said Biogen’s environmental goals were measured by one outside company and audited by another. The zero-emissions goal wasn’t driven by fears of a carbon tax, but was in line with the company’s mission to extend and improve people’s lives, he said.

“We have been aware of risks specific to regulatory requirements for companies to become carbon neutral, but frankly, that wasn’t the driver,” Rodriguez said. “In the end, we care.”