Africa’s reliance on nitrogen fertilisers is anticipated to rise 300% by the year 2050 and proponents of its use to secure food production are earmarking it as a solution to dealing with future climate-change effects on food security.
But new research has shown that this drastic increase in demand for nitrogen-based fertilisers could see greenhouse gas emissions from their use rise to levels that are equivalent to the annual emissions of the entire commercial aviation sector.
The research, summarised in a policy brief by the Institute for Agriculture and Trade Policy, Grain and Greenpeace, shows that the types of fertilisers promoted by chemical companies and by prominent philanthropist Bill Gates and his Alliance for a Green Revolution in Africa are 20% more damaging than previously estimated.
Researcher Timothy Wise refers to Gates’s book, How to Avoid a Climate Disaster, in which the billionaire states: “To grow crops, you want tonnes of nitrogen — way more than you would ever find in a natural setting.”
It is estimated that climate change will reduce the production of staple food by 50% as a result of the heating expected in the year 2080.
But Wise said that about 10% of direct emissions come from synthetic nitrogen fertiliser applied to crops.
Researchers in the recent study used improved data on direct field emissions and incorporated emissions from the manufacture and transportation of nitrogen fertilisers.
Wise conducted research that showed that the Alliance for a Green Revolution in Africa is not achieving the desired outcomes from promoting the use of these fertilisers.
“Bill Gates is just plain wrong when he says the only way to grow food is with synthetic fertilisers. Crops need nitrogen and, in many areas, they can get most or all of what they need from improved agroecological farming,” he said.
Emissions from nitrogen fertilisers are reportedly more than 200 times more harmful than carbon dioxide.
In the early 2000s, African leaders adopted a 12-point resolution on the use of fertiliser as part of efforts to achieve an African “green revolution”.
But the United Nations Environment Programme (UNEP) has recognised the severity of environmental risks associated with the synthetic use of nitrogen on peoples’ health and the environment.
In 2019, member states signed the Colombo Declaration on Sustainable Nitrogen Management with the aim of halving nitrogen use, particularly in agriculture because it is driving pollution of water systems and further harming soil health.
UNEP is instead promoting the use of agroecological practices that promotes regeneration and conservation.
The organisation’s head of the ecosystem division, Susan Gardner, said political buy-in is needed to overcome the use of nitrogen fertilisers.
“Financial incentives and political buy-in will be necessary to overcome the many obstacles in the way of nitrogen-light farming methods, the sustainable use of nitrogen offers a triple win — for the economy, for human health, and for the environment
Mark Sutton, a lead researcher at the Centre for Ecology and Hydrology in the United Kingdom, said his study found that 80% of nitrogen is wasted and lost to the environment.
African countries are highly dependent on nitrogen fertilisers but have started using micro-dosing methods, which is promoted as a way to use less fertiliser but improving yields.
According to the UN’s Africa Renewal magazine, between 2005 and 2015, Ethiopia recorded the highest proportional increase of fertiliser use per hectare, from 1 kg to 24kg. It quoted a 2015 World Bank report that found, during the same period, Ghana’s fertiliser use increased from 20kg to 35kg a hectare and Kenya’s from 33kg to 44kg, resulting in yield increases varying from 18% to 56%.