Way back in 1896, a Swedish scientist suggested that carbon dioxide traps heat in the atmosphere and can cause the climate to change. In the 120 years since, we’ve seen more than 500 billion tons of carbon dioxide build up in our atmosphere. The evidence behind climate science has only grown more compelling, but there have been decades of debate about how alarmed we should be.

Specifically, the scientific research on understanding and forecasting the impacts of climate change—on our environment, our economies, and our countries—has been building rapidly. In the early 1990s, the answer from the first globally comprehensive assessment of how alarmed we should be was “we’re not sure.” By 2001, it was “probably,” followed soon after by “this looks bad,” and in 2014, it was “Houston, we have a problem.”

In just the past year—last December 2015—more than 195 countries agreed to set an aggressive global target, based on scientific understanding of climate change and its effects, to dramatically slash greenhouse gas emissions.

Through the Paris Agreement, governments integrated science into decisions about climate action—and companies now have a way to integrate it into their business. Today, climate action now includes three science-based aspects: a long-term climate goal, emissions-reductions targets to reach that goal, and tools so that companies can act on climate with the confidence that they are contributing to a shared global direction.

Until recently, because they did not have the certainty of the Paris Agreement, setting a climate target—any climate target—was the best any company could do. Therefore, some companies have set targets tied to regulation, others on their best assessment of what they deemed they could do to act, and yet others set stretch goals to ignite companywide challenges. Today, more than 80 percent of Fortune 500 companies have targets to reduce carbon emissions.

But now, companies have a North Star: The science that lies at the foundation of the Paris Agreement says we have a specific global temperature target that can be achieved by clearly defined annual carbon dioxide emissions reductions. Generally speaking, that target requires a global reduction of carbon emissions by 40-70 percent by 2050 to meet the goal of limiting global average temperature rise to “well below 2˚C.” This global temperature goal and carbon dioxide target, both based in science, can inform how companies set their targets going forward—and contribute to the aims of the Paris Agreement.

Companies also now have tools to integrate science into their decisions and update their own targets. The Science-Based Targets Initiative is the gold standard for companies to credibly set and report emissions reductions consistent with the global goal. The initiative helpfully defines a process to commit to science-based targets, offers eight methodologies (some of which include free online tools), and provides a process to check targets to ensure credibility at no charge to companies.

BSR understands that navigating the new agreement and tools can be challenging. We have been working with our more than 250 members and partners to integrate science into corporate climate targets. Our work with General Mills helped them set ambitious targets and catalyze stakeholder alignment around reducing emissions from one of their toughest sources: deep in the supply chain.

And through the We Mean Business coalition, we’ve translated the Paris Agreement for business.

With early leadership examples like this, more than 170 companies have already begun the process or set targets linked to the global temperature goal set in Paris. Now that they have the goal, the target, and the tools, it’s time for more companies to chart a course toward the climate North Star of the Paris Agreement.