How to scale up land-based Climate Mitigation in Portugal
In a new report, we explore how the portfolio of land-based mitigation technologies and practices (LMTs for short) we created for Portugal could become widely adopted. We call these scaling scenarios.
We’re using these scenarios to develop simulation models that anyone can use to reliably estimate how much carbon could be stored in each of these scenarios. Reliable estimates are pretty useful: they can potentially inform everything from individual farmers’ soil management practices, to national climate plans and international climate negotiations.
The our portfolio is made up of LMTs, carefully selected for Portugal, and designed for Portugal’s croplands, grasslands, and forests. These are: croplands management, grasslands management, forest management, and agroforestry.
Here are some potential benefits associated with scaling up each LMT that policymakers should be aware of – as well as some of the possible risks and barriers.
Croplands Management
For managing Portugal’s croplands, we analysed the prospects of precision agriculture as a possible way of farming that is good for both farmers and for sequestering carbon in the soil.
Precision agriculture is a way of managing a farm that uses information technology to observe, measure and respond to variability in crops. When it’s done right, it can help ensure crops receive exactly what is needed for optimum health and productivity, given the relevant soil, terrain, weather and yield data.
These techniques could potentially produce a range of benefits in the Portguese context. They could reduce things like water consumption, herb and pesticide use, and input costs, while potentially also increasing yields – all important factors in a country where climate change is expected to have a major impact on farming in the future.
The benefits of precision agriculture would be most pronounced in Portugal’s southern Alentejo region, where the lack of water can be a major issue for farmers.
Grassland Management
For Portugal’s grasslands, we explored the possibility of sowing biodiverse grasslands that are rich in legumes. Research suggests that fields like these are both more productive, and have an increase soil organic matter, which means they are better for carbon sequestration. These biodiverse, legume-heavy grasslands could have a carbon sequestration potential of 6.48 tCO2.ha-1.yr-1 for a period of 10 years.
Implementing these more sustainable biodiverse grasslands in Portugal could reduce the use of nitrogen fertilizers, increase the production of biomass and soil fertility and contribute to an increase in the volume and quality of dairy production. It could also reduce production costs for farmers by slowing the consumption of feed and raw materials.
But a barrier to this method taking off at scale is that it doesn’t feature in Portugal’s national strategies.
Forest Management
Forests cover about 35% of Portugal’s land area, and provide significant economic, environmental and social value – particularly to Portugal’s wood and cork industry. But they don’t serve as a consistent carbon sink, due to the severe forest fires that Portugal is vulnerable to.
As a result, Portugal is actively trying to invest in afforestation and reforestation with low-growing species like cork oak and stone pine. These trees they are more resistant to drought and extreme temperatures, which helps mitigate the risk of severe forest fires.
Agroforestry
Another good option for Portugal is agroforestry – more specifically, the traditional Montado agroforestry system (known as a “Dehesa” in Spain). A Montado is a unique, biodiverse agroforestry system that has been practiced in the Iberian Peninsula for centuries. It include a grass layer, a tree layer and sometimes also a shrub layer – all of which contribute to carbon sequestration. Montados are used for grazing livestock like pigs, sheep cows and goats, but they also produce forest products like cork.
If farmers could be encouraged to plant more cork trees on their grazing lands to create a Montado system, this would not only increase those areas’ retention of CO2, but it would also be good for the quality of their soil (and provide some welcome shade for their animals.)