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Global Calculator weighs into climate change mitigation debate

Save energy or decarbonise energy - what’s the best option for the climate? DECC’s new global calculator launched on Wednesday will tell you. But guess what, the biggest impact could be from modifying agriculture and diet instead.

An online global forecasting model drawing on input from more than 150 international experts will be launched by the Department for Energy & Climate Change (DECC), Climate-KIC and Mott MacDonald on Wednesday (28 January).

The Global Calculator comprises data on land, energy, food and climate systems and allows users to explore the effects that modifying global production and consumption in key areas will have on mitigating climate change.

"The impact of appliance demand on global energy use is relatively small. This is a positive story, as it illustrates that we can have development and still mitigate climate change.  - Tom Bain, DECC

Users of the tool will be able to adjust key factors such as land use, buildings efficiency, take up of renewable energy sources or transport use, to test the impacts on projected global temperatures.

The aim of the global energy model is to explore different pathways which could limit the rise in global mean temperature to 2oC by 2100 while ensuring good living standards for the world’s population, estimated to rise to around 10bn by 2050.

While most studies have looked at individual systems in isolation, the Global Calculator integrates a range of critical factors affecting climate change into a single model, allowing users to examine the relative benefits and difficulties of different courses of action.

Sophie Hartfield, Global Calculator project leader at DECC, said: "The Global Calculator is designed to be a debating platform, where different organisations might have different views about how we should be tackling climate change, and can test those views using a common model.

"If you believe that we can limit global warming to just 2oC, this gives businesses a tangible idea of what that world might look like – how many wind turbines we might have to build, how much solar we will need to install, how many nuclear power plants we may need and at what level supply of renewable energy will exceed demand, calling for action in other areas such as farming practices and diet."

The Global Calculator will also include more than 10 ‘pathways’ which show routes to achieving international climate change goals while allowing for acceptable global living standards.

Four were designed by DECC, based on varying estimates of consumer activism or action on deforestation, while the others were provided by organisations such as Friends of the Earth, Imperial College Centre for Energy Policy and Technology and Mott MacDonald. A number of other organisations including academic institutions and non-governmental bodies are also planning to explore further scenarios which could limit the global mean temperature rise to no more than 2oC.

Simon Harrison, group strategic development manager at Mott MacDonald and himself part of the team which devised the company’s pathway, said: "What came out as most important in global efforts to reduce climate change was using less energy; giving the principal focus to decarbonising energy supply instead would be more costly and less effective."

Harrison added: "What surprised us was the extent to which agricultural and dietary factors were among the most powerful elements in mitigating climate change."

Tom Bain, Global Calculator lead modeller at DECC said that comparing different factors in the model led to unexpected and sometimes promising outcomes.

"The fact that the world wastes around a quarter of all food means we have great scope to reduce the pressure on land, particularly forests," said Bain.

"What surprised us was the extent to which agricultural and dietary factors were among the most powerful elements in mitigating climate change." - Simon Harrison, Mott MacDonald

He added: "On the flip side, the impact of appliance demand on global energy use is relatively small. This is a positive story, as it illustrates that we can have development and still mitigate climate change. For example, we can aim for the world’s population to have access to important labour saving devices, such as washing machines, whilst still being on a 2oC pathway."

Each pathway will be openly shared on the publically accessible Global Calculator, which will be launched by DECC, Climate-KIC and Mott MacDonald at the Royal Society on 28 January 2015.