According to a new study by Lorenzo Rosa from Carnegie, irrigation could be a strong tool for increasing the world's food supply as climate change alters the patterns of precipitation.
An irrigation strategy being deployed in a field. Image Credit: Unsplash.
This would mean that over a billion extra people could be fed without the need for transforming natural spaces into farmland.
The study has been reported in the Environmental Research Letters journal.
Population trends indicate that we will need to double global food production by 2050. To accomplish this, we will either need to clear more land or farm more efficiently, despite the increased stresses of a warming world.
Lorenzo Rosa, Carnegie Institution for Science
Transforming unfinished land into farms reduces biodiversity and worsens climate change. However, low crop yields in surviving farmland could be enhanced by modern technology.
However, it’s crucial to evaluate these intervention strategies to see which ones will lead to the greatest increase in food production and the lowest environmental impact.
Lorenzo Rosa, Carnegie Institution for Science
At present, two-thirds of the world’s crops have been restricted by rainfall. Climate change is anticipated to both alter precipitation patterns and increase heat stress on plants. This implies that depending on just rain will not sustain the high demand for food.
Irrigation is one option that could be adopted for enhancing the productivity of farmland. Studies have shown that irrigated crops are twice as productive as those that depend just on rainfall.
But irrigation already constitutes between 85 and 90% of human water consumption. However, is it possible to utilize irrigation to increase food production without establishing water shortages?
Sustainable irrigation depends on locally available water sources and groundwater, without draining them beyond what precipitation could replace or harm freshwater ecosystems. Rosa set forth to identify if such strategies could be extended to improve agricultural productivity and reduce the negative environmental effects of water use.
Rosa discovered that under present conditions, there is the availability of sufficient water from local and renewable sources to extend sustainable irrigation for more than 35% of farmland throughout the world. This promotes crop productivity to feed around 1.4 billion more people.
But climate change will make this calculus highly complicated.
As the world keeps warming, Rosa’s review denotes that besides heat stress and variations in rainfall, climate change could also make the process of water evaporation faster, thereby reducing irrigation efficiency.
At the same time, high levels of atmospheric carbon dioxide could make crops grow somewhat in a more productive manner, which may put an end to this worry. All of these competing factors imply that extra research is required to widely understand the possibility of sustainable irrigation for food production that is on the continuous rise.
Rosa’s study denotes that building long-term water storage reservoirs could allow endurable irrigation to feed around 1.2 billion more people compared to depending on just renewable water resources.
Rosa indicates that the United States, Russia, Brazil, and Nigeria exhibit the highest potential for tenable irrigation under extreme warming conditions by making use of water storage facilities, although such kinds of programs will also be possible in Eastern Europe, Latin America, and Sub-Saharan Africa.
There are important questions that still need to be fulfilled in the following research projects concerning the possible impacts of sustainable irrigation plans on water quality as a result of increased fertilizer use, as well as the land-use and socio-economic effects of building water-storage infrastructure.
But Rosa’s study makes an evident case that sustainable irrigation could ease poverty and hunger while reducing the environmental threats of clearing natural land for agricultural causes.
Ensuring sufficient and equitable access to food while reducing agriculture’s environmental impacts is one of the greatest societal challenges of the 21st century. This work demonstrates that careful deployment of irrigation can help the world meet these demands with minimal environmental impacts.
Lorenzo Rosa, Carnegie Institution for Science
Journal Reference:
Rosa, L. (2022) Adapting agriculture to climate change via sustainable irrigation: biophysical potentials and feedbacks. Environmental Research Letters. doi.org/10.1088/1748-9326/ac7408.