Climate change: Staple food crops do not want global warming
Cancun - Taking steps to control global temperatures is a key issue at the UN talks on climate change in Cancun. Within the next four decades maize prices could rise by up to 131 percent, there could be 17 million more undernourished children in the poorest countries, and some African farmers might have to give up agriculture if the planet keeps getting hotter, new studies show.
“[We wanted] … to get countries in Cancun to take action now to keep the global temperature increase below two degrees Celsius by the turn of the century – otherwise we are headed towards a four degree rise if greenhouse gas emissions remain unchecked,” said Phillip Thornton, of the Kenya-based International Livestock Research Institute (ILRI), who used climate models in a study showing the serious impact of a four-degree Celsius rise in temperature on food production in Sub-Saharan Africa by 2090s.
The Intergovernmental Panel on Climate Change (IPCC) noted in its latest assessment that a two-degree Celsius increase in global temperatures by the turn of the century would have a catastrophic effect: water stress in arid and semi-arid countries, more floods in low-lying coastal areas, coastal erosion in small island states, and the elimination of up to 30 percent of animal and plant species.
Thornton said his study was prompted by a conference called '4 degrees and beyond' organised at Oxford University in 2009, where the UK Met Office had warned that a 4 degree increase in the global temperature was quite possible by the end of this century and even earlier.
Much academic attention in the agriculture sector has centred on 2050, by which time the global population is expected to increase from around 6.3 billion today to 9.1 billion, adding a third more mouths to feed, according to the UN Food and Agriculture Organization.
A comprehensive study led by Gerald Nelson and Mark Rosegrant of the International Food Policy Research Institute (IFPRI), projected the possible impact of climate change on three of the world’s main staple foods - maize, rice and wheat - from 2010 to 2050.
The study used various combinations of income and population growth juxtaposed with temperature and rainfall levels ranging from slightly to substantially wetter and hotter. Crop yields and prices fared best when global temperatures rose by one degree Celsius by 2050, IFPRI noted. Other scenarios saw rice yields plunging and maize production dropping considerably, even in countries such as the United States of America, while prices of the staples soared.
The IFPRI study showed that a perfect scenario of sustained higher incomes, lower population growth and effective cuts in greenhouse gas emissions had a dramatic effect on the number of malnourished children in developing countries, bringing it down by 45 percent between 2010 and 2050.
“Economic development also influences consumer patterns, as income growth in Japan after World War II has shown – the Japanese reduced rice consumption, opting for much higher value foodstuffs such as fruits, vegetables, meat and fish [rather than carbohydrate-rich grains],” Nelson pointed out.
''[We wanted] … to get countries in Cancun to take action now to keep the global temperature increase below two degrees Celsius by the turn of the century''
When incomes improved, people tended to produce fewer children, and were better able to provide good quality food and education. Similar patterns have begun to emerge in China, the IFPRI study said.
All these factors would have an effect on the demand for staples, bringing prices down. “But again, only in the case of water-intense rice, as the pressure on cereals - which can be used as animal feed, such as maize - could increase,” said Nelson. On the other hand, higher incomes would also place farmers in a better position to invest in new technologies to boost crop yields.
He also suggested that governments become proactive about family planning programmes and encourage the distribution of contraceptives.
Global temperatures could be kept below the two-degree Celsius tipping point if harmful greenhouse gas emissions were allowed to peak by 2015, and subsequently by 80 percent to 50 percent until 2050, the IPCC said.
The International Energy Agency warned in its World Energy Outlook 2010 that the demand for oil and coal – the two biggest causes of greenhouse gas emissions – would have to peak before 2020 to keep the global temperature increase below two degrees Celsius.
Out of Africa
Nearly all population growth by 2050 is expected to occur in developing countries, according to the UN, with Sub-Saharan Africa's population growing fastest - by 108 percent – adding 910 million people.
The IFPRI global projections were accompanied by more detailed studies of African countries, which used the same climate models to show that as populations increased and soaring temperatures hit crop production, the numbers of malnourished children climbed by millions, even in the more developed countries such as South Africa.
Only in Malawi, where the local modeller took into account nutrition policies currently in place, did the projections show that the number of malnourished children could fall by 2050.
Implementing policies to help countries adapt, make their people resilient to the impact of climate change, and reduce the risk of disaster was critical, said Lindiwe Sibanda, head of the Food, Agriculture and Natural Resources Policy Analysis Network (FANRPAN), an African think-tank.
Absalom Manyatsi, an agronomist and the lead author of the study on Swaziland, pointed out that his country, where the impact of climate change would be aggravated by a high incidence of HIV/AIDS, did not have a climate change adaptation policy. In fact, the government intended to increase sugarcane production for biofuel at the expense of maize production.
Neighbouring Mozambique has an adaptation policy but is extremely vulnerable to natural hazards - 20 of the country’s 128 districts are highly prone to drought, 30 to flooding, and 7 to both risks - exposing about 43 percent of the population to natural hazards said Genito Maure, lead author of the case study on Mozambique and a senior lecturer at the Eduardo Mondlane University in Maputo, the capital.
Agriculture’s contribution to the gross domestic product (GDP) of Mozambique had dropped quite sharply from about 45 percent in 1989 to 20 percent in 2000, and up to 2010 had stabilized at around a quarter of GDP. “The climate change projections show food production is going to plunge even further with temperatures going up,” Maure said.
Most people still depended on farming for an income and the country needed to make agriculture resilient, for instance by investing in infrastructure such as putting in a road network to improve access to markets and the flow of grain from the more fertile north to other parts of the country, he said.
Population growth would be a challenge in many African countries, said Delali Nutsukpo, a senior agriculture official in the Ghanaian government and lead author of the country’s case study. “We need to take measures to control population while investing in rural livelihoods programmes – but will that happen?”
Even more dismal
In the ILRI study Thornton painted a rather gloomy picture: crops failed every second year in parts of Southern Africa, and he was sceptical that international climate policies would succeed “in confining global warming to … [a rise of 2 degrees Celsius] - even this will require unprecedented collective will and collective action”.
Data collection and dissemination on the weather as well as the land would have to improve, so as to develop adaptation strategies. At the moment, “estimates of the cropland extent in Africa range from about 1 to more than 6 million sq km … depending on the choice of satellite … The uncertainty in such basic information ("where are crops grown, and how much of them is there?") adds considerable difficulty to the quantification and evaluation of impacts and adaptation options,” the ILRI study commented.
It also urged investment in preserving genetic diversity so farmers would have a bigger pool of choices to cross-breed, and in providing support for smallholder farmers by developing community-based adaptation tools that were easy to implement.
Previous IFPRI research has indicated that least US$7 billion per year should be spent on biological research, extending rural roads, and expanding irrigation systems and improving their efficiency, to compensate for the loss of food production brought on by climate change by 2050 and beyond.