More companies are working on being more sustainable, but small steps won’t be enough to avert a global temperature spike, experts say. Instead, major, strategic shifts using science-based targets are the way to go.

So far, 90 companies worldwide have set and approved science-based targets, and more than 250 others have committed to setting them, according to the Science Based Targets Initiative (SBTI), a partnership of CDP, World Resources Institute, World Wildlife Fund and the United Nations Global Compact. The partners developed SBTI criteria (PDF) that they use to verify each company’s science-based target.

Netherlands-based beer brewer Heineken said Monday that it plans to set science-based emission-reduction targets and increase its use of renewable energy, to 70 percent by 2030 from 14 percent currently. Finding renewable heat generators, such as brewing boilers in Vietnam that are fueled with rice husks from local farmers, is harder than procuring wind and solar power but worth the effort, the company said.

Heineken also plans to set new emission-reduction targets for distribution, cooling and packaging, where it will have to work with suppliers.

"Beyond production, distribution and cooling, we are also going to take a close look at our packaging, because it represents a significant portion of our carbon footprint," Heineken Chairman and CEO Jean-Francois van Boxmeer said in a statement. "We invite our business partners and others to work with us to reduce emissions across our business."

We invite our business partners and others to work with us to reduce emissions across our business.

To set science-based targets for climate, land use and water, companies identify scientific consensus about what reductions and specific actions are necessary to conserve vital resources, and then figure out what their share of environmental protection should be, looking at their position in their industry and the industry’s position in the broader economy. The primary goal is to set targets that, taken together with reductions from other companies and sectors, is more likely to avoid a 2-degree-Celsius temperature increase in global temperature.

Mars set science-based targets last year for carbon emissions, water and land use. The global food and drink maker plans to cut emissions from its own operations and from suppliers by 27 percent by 2025, and by 67 percent by 2050, from 2015 levels. The company will cut its own emissions by 40 percent by 2025, and by 100 percent by 2040.

"When trying to set carbon target, let’s have a conversation in our business about what we can do to try and deliver these targets, based on scientific research," Kevin Rabinovitch, Mars’ global vice president of sustainability, said Thursday at GreenBiz 18 in Phoenix. "Let’s not have an argument of what the targets should be. Let’s let the science determine that, and let’s figure out what we can do to meet those."

Let’s not have an argument of what the targets should be. Let’s let the science determine that, and let’s figure out what we can do to meet those.

After cutting its global water use by 18 percent from 2007 to 2015, Mars aims to boost water efficiency in its factories by 15 percent in water-stressed regions, by 2020. The company also is helping its supplier farmers obtain training and technology to cut their water use. For example, Mars is working with rice farmers in the United States and Pakistan to try an alternate wetting and drying irrigation technique that saves water while maintaining crop yields.

To be sure, some carbon-heavy industries, such as oil production, petrochemical manufacturing and mining are finding it challenging to set science based targets.

Consumer-facing companies generally have more options.

HP set science-based carbon emissions targets last year. The company aims to cut its own emissions by 25 percent by 2025, from 2015 levels, and cut the emissions intensity from the use of its products by 25 percent by 2020, from 2010 levels. The company also committed to cut the carbon emissions intensity from first-tier production and product transportation suppliers by 10 percent by 2025, from 2015 levels. And HP aims to source 40 percent of its global electricity from renewables, and eventually reach 100 percent.

HP developed customized science-based targets for each supplier to make it easier for them to comply with HP’s emissions targets, Maxfield Weiss, global social & environmental responsibility manager at HP, said at GreenBiz 18.

While HP tracks the individual emissions performance of suppliers, some suppliers are eager to set their own science-based targets, he added.