More than 100 companies including Ikea, Coca-Cola, Walmart and Kellogg have pledged to set emissions reduction targets in line with scientific assessments on how to keep temperature rises below 2°C.
Corporate science-based targets are being advocated by a coalition consisting of the World Resources Institute (WRI), the CDP, the UN Global Compact and WWF.
Speaking at a side-event on science-based targets at the UNFCCC talks in Paris, Kevin Moss, business centre director at the WRI, said typically, companies would set emission reduction targets in line with what they thought they could achieve, and then stretched themselves slightly so they knew they would meet the target.
"Science-based targets start with the principle that what we are trying to do is solve the problem of catastrophic climate change and there isn't really a half way point to avoiding catastrophic climate change, you're either on a trajectory to meet it or you're not.
"If you're making the effort to reduce emissions, it's worth making that little bit extra effort to avoid catastrophic climate change," he said.
There are various methods companies can use to calculate a science-based target and the partners are hoping that by bringing them together under one umbrella they can avoid further variation. Examples of science-based targets approved under the umbrella include the sector approach based on work by the International Energy Agency, and the Centre for Sustainable Organisation's (CSO) context-based carbon metric. This compares the greenhouse-gas emissions of organisations with specific targets taken from science-based mitigation scenarios.
There are also science-based targets based on methodologies drawn up by companies such as BT and Mars.
Under the corporate scheme, once companies pledge to reduce emissions they have two years to submit new targets to the WRI and its partners to verify. Coca-Cola, Dell, Kellogg, NRG Energy, P&G and Sony are among 10 companies to have already received approval for science-based targets. Together they should reduce emissions from their operations by 799 million tonnes CO2 over the lifetime of the targets. The 10 companies are also committed to reducing indirect emissions in their supply chains.
Setting a science-based target is "not trivial" for companies, Moss said, since they need to measure their scope 3 emissions, which include those produced during its lifetime of a product, which are hard to measure.
"It leads you towards developing a portfolio of products and services that will provide for a low carbon society. It might mean substituting a portfolio of products that relies on fossil fuels to one that doesn't," he said.
Business who set such targets will be forced to look for opportunities to make efficiencies in their operations and supply chains, Moss said. They will also benefit from improved credibility and leadership, and increased competitiveness, he added.
Science-based targets announced in Paris include Kellogg, which committed to a 15% reduction in CO2e emissions per tonne of food produced by 2020 from a 2015 base-year, and an absolute 20% reduction in emissions from its supply chain by 2030.
NRG Energy pledged a 50% reduction of absolute scope 1, 2 and 3 emissions by 2030 compared with 2014. The company's long-term goal is a 90% reduction in absolute emissions by 2050 from 2014 levels.
Pedro Fabia, technical director at the CDP, said that science-based targets could be either intensity targets or absolute targets. "We'd prefer absolute targets. But there are instances where the intensity tells you more about the performance of the company. There is a greater relationship between the CO2 emissions and the physical activity in certain industries," he said.
Meanwhile at COP21, scientists predicted that global carbon emissions are projected to stall in 2015. New research by the University of East Anglia (UEA) and the Global Carbon Project, published in Nature Climate Change found that, in 2014, global CO2 emissions from fossil fuels and industry grew by just 0.6% - marking a year-on-year slow down.
The projection for this year is a second year of slow growth or even a small decrease of 0.6% in global emissions. This would be the first decline during a period of strong global economic growth, the scientists said.
Professor Corinne Le Quéré, director of the Tyndall Centre at UEA, who led the data analysis, said: "These figures are certainly not typical of the growth trajectory seen since 2000 - where the annual growth in emissions was 2-3%."
However, she cautioned that the figures were estimates and there could instead by a rise of 0.5%. The projected decline was largely down to reduced coal use in China, the scientists found. The drop was likely to be only temporary, since developing countries are still heavily dependent on coal for economic growth, she added.
The research shows the biggest contributors to global emissions in 2014 were China (27%), the US (15%), the EU (10%), and India (7%). UK emissions contributed 1.2% to the world total, the research found.
