{"id":12804,"date":"2026-06-20T12:25:11","date_gmt":"2026-06-20T12:25:11","guid":{"rendered":"https:\/\/dev.iita.org\/news-item\/while-we-are-sleeping-high-night-temperatures-affect-our-morning-coffee\/"},"modified":"2026-06-29T21:46:47","modified_gmt":"2026-06-29T21:46:47","slug":"while-we-are-sleeping-high-night-temperatures-affect-our-morning-coffee","status":"publish","type":"news-item","link":"https:\/\/iita.org\/fr\/news-item\/while-we-are-sleeping-high-night-temperatures-affect-our-morning-coffee\/","title":{"rendered":"While we are sleeping &#8211; High night temperatures affect our morning coffee"},"content":{"rendered":"<p class=\"wp-block-paragraph\"><em>First research report on evidence-based climate change affecting Arabica coffee growing areas calls for immediate action<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><figure id=\"attachment_13200\" aria-describedby=\"caption-attachment-13200\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"http:\/\/www.iita.org\/wp-content\/uploads\/2015\/04\/1024_coffee_0617.jpg\"><img fetchpriority=\"high\" decoding=\"async\" class=\"size-medium wp-image-13200\" src=\"https:\/\/iita.org\/wp-content\/uploads\/2026\/06\/1024_coffee_0617-300x232.jpg\" alt=\"Picture of Aless andro Craparo registering coffee berries with smallholder farmers in Northern Tanzania. \" width=\"300\" height=\"232\" \/><\/a><figcaption id=\"caption-attachment-13200\" class=\"wp-caption-text\">Aless andro Craparo registering coffee berries with smallholder farmers in Northern Tanzania. Photo from P. van Asten.<\/figcaption><\/figure><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The first on-the-ground evidence that climate change is already having an impact on the Arabica coffee sector in the East African Highl ands region is shown in a <a href=\"http:\/\/www.sciencedirect.com\/science\/article\/pii\/S0168192315000830\" target=\"_blank\" rel=\"noopener\">\u00e9tudier<\/a> called \u201c<em>Coffea arabica<\/em> yields decline in Tanzania due to climate change: Global implications\u201d published earlier this month in <a href=\"http:\/\/www.sciencedirect.com\/science\/article\/pii\/S0168192315000830\" target=\"_blank\" rel=\"noopener\">Agricultural  and Forest Meteorology Journal<\/a> by the <a href=\"https:\/\/iita.org\/fr\/\" target=\"_blank\" rel=\"noopener\">Institut International d'Agriculture Tropicale<\/a>, le <a href=\"http:\/\/ciat.cgiar.org\/\" target=\"_blank\" rel=\"noopener\">International Center for Tropical Agriculture<\/a>,  and the <a href=\"http:\/\/www.wits.ac.za\/\" target=\"_blank\" rel=\"noopener\">University of Witwatersr and<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The study demonstrates that over the last 49 years, there has been a + 1.42 \u00b0C increase in night temperatures which has led to <em>Arabica<\/em> yield decrease of 195 kg\/ha. The consequences for smallholders in the region are dramatic as it represents losses of 46 percent. \u201cCoffee yields have declined to their lowest point in years, with many farmers in Tanzania giving up on coffee completely,\u201d says Aless andro Craparo, the main author of the study.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The sensitive <em>Coffea arabica<\/em> berries need low temperatures to grow well  and produce high quality coffee for consumption, which is why they are best suited to the cool tropical highl ands of East Africa, typically between 1000 &#8211; 2300 m above sea level. Using data from the northern Tanzanian highl ands, the study verifies for the first time the increasing night time (minimum) temperature as the most significant climatic variable being responsible for diminishing <em>Arabica<\/em> coffee yields between 1961  and 2012  and proves that climate change is an ongoing reality. The researchers S andro Craparo, Piet van Asten, Peter L\u00e4derach, Laurence Jassogne,  and Stefan Grab used independent open-access datasets, which confirm that out of many climate variables, night temperature has the greatest correlation to coffee production.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The results of the study projected forward means that without substantial adaptation strategies, the average coffee production in Tanzania will drop to 145 \u00b1 41 kg\/ha by 2060. This is approximately an additional 35% loss in yield for the farmer, which could mean a decrease of up to US$28 million in <em>Arabica<\/em> export earnings for the country.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u201cThe industry is aware of the impact of climate change on coffee production, but they need hard data to prove to regional decision makers, how urgently climate mitigation strategies need to be put in place,\u201d says Dr Piet van Asten, IITA Country Representative in Ug anda  and agronomist working on sustainable intensification of cropping systems. \u201cThe study is the first of its kind globally providing essential time-series evidence that climate change has already had a negative impact on<em>Coffea arabica <\/em>yields.\u201d Whereas most coffee research focused on changes in rainfall  and mean temperature, this study revealed that minimum temperatures are the biggest threat: the hotter the nights get, the higher the danger for <em>Arabica<\/em>coffee production.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Contrary to the typical constraints found in coffee research linked to rainfall  and drought stress  and the climate projections for future scenarios deriving from it, the observation of minimum temperatures needed for coffee growing leads to clear empiric data  and biological relationships\u2013the hotter the nights get, the higher the danger for Arabica coffee production.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">At night temperatures of 15 \u00b0C  and above, the plant&#8217;s metabolism starts to change, leading to lower yields  and reduced quality, which will have a significant impact on the coffee industries  and processors.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The study, which was done under the <a href=\"http:\/\/ccafs.cgiar.org\/\" target=\"_blank\" rel=\"noopener\">CGIAR Research Program on Climate, Agriculture  and Food Security<\/a> ,  and partly financed by funds from the German Federal Ministry of Economic Cooperation  and Development, <a href=\"https:\/\/www.bmz.de\/en\/\" target=\"_blank\" rel=\"noopener\">BMZ<\/a>, may give the coffee sector the hard figures required to encourage the public  and the private sector to invest in climate change adaptation strategies that will better sustain the industry  and the livelihoods of millions of smallholder farmers who depend on it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For more information:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Andrea Gros, Head of Communication, IITA HQ, <a href=\"mailto:a.gros@cgiar.org\">a.gros@cgiar.org<\/a><br>Catherine Njuguna, Communication Officer, IITA-Tanzania, <a href=\"mailto:c.njuguna@cgiar.org\">c.njuguna@cgiar.org<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u00c0 propos de l'IITA<\/strong>, <a href=\"https:\/\/iita.org\/fr\/\">www.iita.org<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IITA is one of the world\u2019s leading research partners in finding solutions for hunger, malnutrition,  and poverty. Its award-winning research for development (R4D) approach addresses the development needs of tropical countries. IITA works with partners to enhance crop quality  and productivity, reduce producer  and consumer risks,  and generate wealth from agriculture. IITA is a nonprofit organization founded in 1967  and governed by a Board of Trustees. IITA works on the following crops: cowpea, soybean, banana\/plantain, yam, cassava,  and maize. IITA is a member of CGIAR, a global agriculture research partnership for a food secure future.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>About WITS<\/strong> <a>www.wits.ac.za<\/a><br>Wits, a world-class research university in Africa, is renowned for its commitment to academic  and research excellence. It contributes to the global knowledge economy  and local transformation through the generation of high level, scarce skills  and innovative research. At the forefront of a changing society, Wits is an engaged institution, dedicated to advancing the public good. It promotes intellectual communities  and attracts talented students, distinguished academics  and thinkers from around the globe.<\/p>","protected":false},"excerpt":{"rendered":"<p>The first on-the-ground evidence that climate change is already having an impact on the Arabica coffee sector in the East African Highlands region is shown in a study called \u201cCoffea arabica yields decline in Tanzania due to climate change: Global implications\u201d published earlier this month<\/p>","protected":false},"featured_media":12805,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center 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