Food crop production in Nigeria. II. Potential effects of climate change

Abstract

Two separate lines of investigation were adapted from the recommendations of the 1994 United States Country Studies Program (USCP). In one approach, arbitrary incremental scenarios were adopted to assess the response of crop yield to changes in the various elements of climate. Using the erosion productivity impact calculator (EPIC) crop model, tests were conducted to demonstrate how crop yield might respond to changes in rainfall, relative humidity (RH), temperature, solar radiation and CO 2 concentration. The value of one element was altered incrementally while holding constant the values of the others. In the second approach, potential future changes in the yields of maize, sorghum, millet, rice and cassava were simulated based on a scenario specifying mean conditions for 1961-9190 as a baseline and general circulation model (GCM) projections from this for 3 periods: 2010-2039, 2040-2069 and 2070-2099. The results predicted a possible increase in crop yield during the first half of the 21st century to be followed by a decrease during the second half. Enhanced crop yield was explained by projected increases in rainfall, solar radiation, atmospheric humidity and CO 2 concentrations. Lower yields were explained in terms of continued global warming, as a result of which maximum and minimum temperatures approach the limits of tolerance for the modelled crops. KEY WORDS: Climate change · Crop yield · Nigeria · Food productionResale or republication not permitted without written consent of the publisher

Towards a wetter Sudano‐Sahelian ecological zone in twenty‐first century Nigeria

“…These results appear to confirm the climate change scenarios of FMEN (2003), Adejuwon (2006) and IPCC (http://ipccddc.cru.uea.ac.uk). Contrary to the scenarios that both minimum and maximum temperatures will increase however, the maximum and minimum temperatures decreased after 1983-1984.…”

“…Using the observed data for 1961-1990 as the baseline, projections were made for a variety of time slices in the twenty-first century. The results of the analysis indicate: (a) steady and consistent increases in annual rainfall until 2069; (b) increases in both minimum and maximum temperatures; and (c) an increase in vapour pressure (MEFRN, 2003;Adejuwon, 2006; IPCC http://ipccddc.cru.uea.ac.uk).…”

“…Projections of climate change in Nigeria, and in SSEZ in particular, based on Global Climate Models (GCMs) have been made for the twenty-first century (MEFRN, 2003;Adejuwon, 2006; IPCC http://ipcc-ddc. cru.uea.ac.uk).…”

“…cru.uea.ac.uk). The projections reported in Nigeria's First Communication under the United Nations Framework Convention on Climate Change (UNFCCC) were based on the assumption of an annual increase of 1% in atmospheric CO 2 concentration from the current level of 380 ppm to 855 ppm by 2100 (MEFRN, 2003;Adejuwon, 2006;AIACC, 2006). This increase represents a worst-case scenario of greenhouse gas emissions with the potential for a change in climate.…”

“…Recently however, some scenarios (based on greenhouse gas emissions) have suggested that the observed trend towards aridity will be put on hold or be reversed in the twentyfirst century (MEFRN, 2003;Haarsma et al, 2005;Adejuwon, 2006). In fact, Haarsma et al (2005) partly used observed data of the wider Sahel region and established that rainfall has been increasing since the mid-1980s.…”