For climate research, specifically,… Read More physical, economic and social – to produce information that can be used to help decision-making. Integrated Assessment Models: IAMs are computer models that analyse a broad range of data – e.g. You can see how these scenarios are projected to pan out over the course of the 21st century in the charts and maps below. In our study, we examine scenarios produced by the IMAGE integrated assessment model of different ways society could meet the 1.5C and 2C limits. In Intergovernmental Panel on Climate Change (IPCC) scenarios that are consistent with 2C warming, BECCS is assumed to remove an average of 3.3bn tonnes of carbon per year by 2100.īut what if, overall, BECCS does not actually remove as much CO2 from the atmosphere as it emits? Land for foodīefore answering that question, it is worth mentioning that a constraint on using land for climate mitigation is our need to grow food. And they have the potential to remove large amounts of carbon each year, particularly compared to forests since their carbon uptake capacity saturates as trees reach maturity.
Some studies have found increased biodiversity and soil carbon when growing the biofuel miscanthus.
In comparison, bioenergy crops, when grown sustainably, could also provide multiple benefits. It is also important to note, though, the potential warming effect of forests as well – in high-latitude areas, adding trees can warm the climate since their albedo is lower than snowy ground or agricultural land. Tree-planting programmes, where carbon in new trees is tracked and sold for carbon credits, are already providing additional income for farmers.Īfforestation (growing new forests) and reforestation (restoring existing forests), combined with a variety of land management and conservation practices, could remove around 1-2bn tonnes of carbon from the atmosphere per year. Most people know that forests have many benefits, ranging from high biodiversity to improved soil and water quality compared to agricultural land. Instead, we find that protecting and expanding forests could be more effective options for meeting the Paris Agreement. In our new study, published in Nature Communications, my colleagues and I find that expansion of bioenergy in order to meet the 1.5C limit could cause net losses in carbon from the land surface.
And, before now, no studies have looked at these impacts specifically for a scenario that could meet the 1.5C target.
However, the full carbon-cycle impacts of large-scale deployment of BECCS are not well studied. There are many attractive features, since this technology would provide energy – thus reducing our need for fossil fuels – and remove CO2 from the atmosphere at the same time. Model scenarios that limit warming to 1.5C or 2C typically rely on large amounts of “ negative emissions” to extract CO2 from the atmosphere and store it on land, underground or in the oceans.īioenergy crops with carbon capture and storage (BECCS) is, perhaps, the most prominent of the various negative emissions techniques. With the long-term goal of restricting global temperature rise to “well below 2C” or 1.5C above pre-industrial levels now enshrined in the Paris Agreement, attention has increasingly turned to how these limits could be met. Dr Anna Harper is a research fellow and lecturer in climate science in the College of Engineering, Mathematics and Physical Sciences at the University of Exeter.