Innovation in the agriculture, forestry and other land uses sector could reduce greenhouse gas emissions by half

SmithA new paper by Smith et al published in Global Change Biology asks the question, How much land-based greenhouse gas mitigation can be achieved without compromising food security and environmental goals? Authors attempt to answer this question by modelling the potential of supply- and demand-side mitigation options available in the Agriculture, Forestry and other land uses sector, as well as their impacts on one another and on food security.

On the supply side such practices as alternative uses for biomass, and land sparing, have the potential to reduce emissions by 1.5 to 4.3 Gt CO2 equivalent per year at carbon prices of between $20 and $100. For 2011, the International Energy Agency estimated annual emissions as 31.6 Gt CO2 equivalent. Seeking to reduce the carbon footprint of the AFOLU sector while at the same time increasing food production, is a core aim of sustainable intensification, which advocates using inputs in a more judicious manner to achieve greater outputs.

On the demand-side measures such as reducing food waste and shifting to less resource-intensive diets could reduce emissions between 1.5 and 15.6 Gt CO2 equivalent per year. Such solutions may also aid in the fight against food insecurity and hunger.

The paper advocates for action to be taken on both the supply- and demand-sides, which when their maximum potentials are totalled could mean a halving of total global greenhouse gas emissions. Sonja Vermuelen, Head of Research at CGIAR’s research programme on Climate Change Agriculture and Food Security (CCAFS), in her blog on the paper, indicates the importance of policy, both for stimulating a shift to sustainable intensification but also the considerable changes in consumer behaviour that will be required. Political leadership, determination and significant innovation will be needed if we are to reach this goal.

Where are we on climate change?

ID-100103034 (2)Professor Sir Brian Hoskins, Director of the Grantham Institute for Climate Change and advisor to the UK government through the Committee on Climate Change, recently gave a talk at Imperial College London on the latest research and actions around climate change.

Global CO2 levels are currently at 397ppm (parts per million), a level not seen for 4.5 million years. We have increased CO2 levels in the atmosphere by 40% since the Industrial Revolution. While there has been a clear and significant increase in global temperatures since 1850, we have seen a hiatus on temperature rises in the last decade. While sceptics may use this as evidence to support their claims, a decade of cooler temperatures is not outside the range of predictions from climate models.

Global sea levels are rising 3mm per year. While the melting of the Western Antarctic and Greenland ice sheets is contributing around 1mm of this increase, it is unknown how likely this is to accelerate if we reach a threshold point of destabilisation. In the Arctic, recent pictures of the ice cap in mid-September (when it is at its minimum size) show it is half the average size it was in the last century. By 2050-2060 we would expect the arctic ice cap to have vanished come September.

We have seen some significant heat extremes in the past decade: the 2003 European heatwave, 2010 Russian heatwave and more recently the 2012 US drought. Work by NASA scientists Dr James Hansen and colleagues indicates a shift to more frequent and severe bouts of high temperatures. But it is not just heat extremes, as the climate changes we are also seeing cold extremes in certain locations despite remarkable warmth elsewhere. This indicates our ability to predict regional trends is much more limited than our ability to predict global averages and while we may, in the past have viewed climate change as a warming of the planet, now we are trying to understand it as a disruption of our climate systems, one that will have severe and varied results. [Read more…]