FEATURE: Hotter future in store for Tanzania and Malawi
Two new briefs published by the Future Climate for Africa (FCFA) programme highlight future climate projections for Tanzania and Malawi, using the latest results from 34 of the world’s leading climate models. The purpose of the briefs, written by an international collaboration of climate scientists, is to help the countries plan better for climate change.
Globally, southern Africa is one of the most vulnerable regions to the impacts of climate change. Malawi and Tanzania are already experiencing higher annual temperatures, and increases in extreme weather events, including droughts and floods.
The latest climate model simulations show it is likely to get much hotter throughout both countries. In Malawi, it is projected that temperatures will increase by between 0.5°C to 1.5°C by the 2040s, and by between 2.3°C to 6.3°C by the 2090s. Tanzania’s projected temperatures are between 0.8°C to 1.8°C by the 2040s, and 1.6°C to 5°C by the 2090s. This is likely to lead to increased evaporation from soil and open water, like dams, affecting agriculture. This means that, for example, promoting a crop that is sensitive to heat and already battling to grow, is likely to be unsustainable in the long run.
In both countries heatwaves are also likely to happen more often, and be more intense. All models also show an increase in the number of days with temperatures above 30°C – by the 2040s from roughly 10 to 100 days per year in Malawi, and 10 to 80 days per year in Tanzania. There is also a higher likelihood of drought and intense rainfall events, possibly causing flooding.
Future projections for rainfall are less clear. Models show a possibility of both decreased and increased rainfall for Tanzania. For Malawi, almost half of the 34 models show that changes in rainfall are likely to be less than 5%, while the rest disagree on whether it will be wetter or drier. The best way to respond to this uncertainty is to plan for a range of different scenarios, and implement interventions that are beneficial in both a wetter and drier future.
Despite this uncertainty, there are some rainfall characteristics scientists are more confident about. One is a drying trend from September to November throughout Malawi, as well as the October-November-December rainy season in southern Tanzania – both critical times for the agricultural sector. Avoiding crop losses will require planning for reduced water availability and length of the growing season in Tanzania, and delays to the start of the rainy season in November in Malawi. Taking climate change projections into account for particular planning decisions, and considering the range of futures, can support sustainability.
“The climate briefs present key messages about climate model projections; how they suggest the country’s climate could evolve and important considerations for interpreting this information”, says one of lead authors of the publications, Professor Declan Conway. “They are introductory guides for non-expert audiences interested in the nature of the future risks that climate change represents for Malawi and Tanzania, an important step in designing approaches to adaptation”.
Another recently published guide from UMFULA – How to understand and interpret global climate model results – shows how to interpret the climate projections produced by climate models. Professor Declan Conway, explains: “In the guide we explain why there are many options available and therefore choices to be made when using climate model results to describe future climate change.” This guide will also help readers better understand what the models are telling us about likely future climate change for Malawi and Tanzania.
These publications are part of the Future Climate for Africa programme, and in particular a project called UMFULA, which seeks to improve climate information for decision-making in central and southern Africa. UMFULA is an international team of 13 institutions specialising in cutting edge climate science, impact modelling and socio-economic research.
UMFULA is working with stakeholders to inform decision-making relating to agriculture and water infrastructure in the Shire river basin in Malawi, and hydropower, irrigation and water resource management in the Rufiji basin in Tanzania. The country climate briefs were written by scientists from the London School of Economics, University of Oxford, University of Sussex, University of Leeds, the Lilongwe University of Agriculture and Natural Resources, the South African Centre for Scientific and Industrial Research, and Kulima Integrated Solutions.
The country climate briefs have been published with detailed annexes describing the methods and datasets used in the briefs and presenting a wider range of figures, which can be a useful reference for researchers and students. Two-page summaries also highlight key findings.
Read the main brief, summary and annex for Malawi and Tanzania, as well as the guide on how to understand and interpret global climate model results.
For further information, please contact the guide’s lead authors:
Dr Neha Mittal (University of Leeds)
Prof. Declan Conway (London School of Economics and Political Science): D.Conway@lse.ac.uk