Blog: The value of Science Based Targets. Hannah Sewell, Grantham Scholar

April 24, 2017

The value of Science Based Targets
by Hannah Sewell, Grantham Scholar, Grantham Centre for Sustainable Futures

There is a tension in the way that many companies and governments set their sustainability targets. Often, they are based on what these organisations feel they can achieve rather than what science tells us is required.

Before the Paris meeting of the United Nations Framework Convention on Climate Change in 2015, the message was that world leaders needed to limit global warming to two degrees Celsius above pre-industrial levels. All previous targets had been working towards that goal, but there was clear evidence this arbitrary measure did not go far enough. Keeping within two degrees wasn’t going to stop the destruction of Pacific Island Nations by sea level rises or stop the death of the world’s coral reefs. It would also reduce freshwater availability in the Mediterranean by 17 per cent, causing drought and crop losses, and annual heat waves lasting a month-and-a-half.

Keeping below 1.5°C would help though. It would reduce sea level rises to 40cm, meaning the Pacific Islands wouldn’t be drowned and crop losses would be kept within a more manageable limit. Climate extremes would be reduced and more of the world’s coral reefs would survive. Having seen the science, policymakers set a new goal to work towards: 1.5°C. This is a science based target.

It is equally important for companies to consider the science before setting their sustainability targets. If a factory is in an area that can only support the withdrawal of 10,000 litres a day of water, and the factory sets a target to only withdraw 5,000 litres, they have not solved the problem. They might get praise and better publicity for making a start, but the long-term consequences of water scarcity haven’t been avoided, merely delayed. Doing this research beforehand is essential to make sure a target is effective.

In terms of science based carbon reduction targets, companies should stick to the Paris agreement’s framework to keep emissions well below the 1.5°C limit. This means cutting carbon emissions in line with what your sector contributes to emissions, or cutting it by 49% of 2010 levels by 2050 to be in line with global targets. The Carbon Disclosure Project has created lots of resources to help with this and, along with WWF, the World Resources Institute and UN Global Compact, runs a scheme called Science Based Targets aimed at getting business to make meaningful science based targets.

In many cases, companies will need to undertake a life-cycle analysis of their products to find out where the barriers to sustainability truly lie. For example, researchers from the Grantham Centre for Sustainable Futures at the University of Sheffield showed that in bread production, rather than the transport or the baking, it is the nitrogen fertiliser that contributes the highest carbon emissions. So, if you want to cut the carbon footprint of a loaf of bread, the best place to start might not be in the bakery, but back on the farm, where fertiliser might be changed or reduced.

Ultimately, science based targets can lead to real change and prevent greenwashing. A target is useless in the fight for a sustainable future unless it solves the underlying cause of an organisations carbon footprint. All companies should aim for effective and meaningful targets, and that means ones based on science.

Hannah Sewell
Hannah Sewell is a third year Grantham Scholar, completing an interdisciplinary PhD project through the Grantham Centre for Sustainable Futures at the University of Sheffield. Working under the supervision of Professor David Beerling FRS in the Department of Animal and Plant Sciences, her project is focussed on identifying and isolating genes for engineering crops that are more resilient to drought in areas with high levels of carbon dioxide. At the same time, Hannah is participating in the ground breaking Grantham Scholars training programme, which supports interdisciplinary PhD students working on sustainability projects, so that they can learn how to turn academic ideas into evidence-based action on sustainability. 


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