Evidence of Climate Changes in a Tropical Rainforest: Case Study Kakamega Tropical Rainforest
Authors: Wanyonyi Phanice N. , H. Tsingalia Mugatsia , Omayio Dennis O. , Mzungu Emmanuel 
Published: November 2021

Aims: To assess trends in rainfall and temperature as evidence of climate change in the Kakamega tropical forest ecosystem over the last 30 years (1980-2010).

Study Design: Secondary data on temperature, rainfall and other climate related phenomena that have occurred within the Kakamega forest ecosystem over the last 30 years were obtained from the Kenya Metrological Department (KMD), Kenya Agriculture and Livestock Research Organization (KALRO), and local metrological stations and analysed to assess trends. This data was supplemented with data from questionnaires and structured interviews.

Place and Duration of Study: The study was carried out among forest adjacent communities in the Kakamega tropical forest ecosystem between April and December 2020.

Methodology: Data on awareness and preparedness for climate change was collected using structured questionnaires, focused group discussions (FGD) and structured interviews. Three villages in the east, west, north and south of the forest that are within a 2km radius of the forest were randomly selected for sampling. From the 52,729 households, 397 households were randomly chosen from each of the three selected villages. Questionnaires targeted family heads in all the selected households. The questionnaire sought first-hand information on climate change awareness and impacts of climate change among the forest-adjacent communities. Each questionnaire comprised of open and closed-ended questions. Focused Group Discussion involved specialized groups of women, village elders, local administrators, CBOs working in the ecosystem, among others. Further information was obtained using key informants. A total of forty-eight (48) key informants were randomly selected for discussion. The interview method involved key personnel working within the forest ecosystem which included staff from KWS, County environmental officers, National Environment Officers, Agriculture officers at the national and county levels. The interviews focused on preparedness, mitigative and adaptive capacity to climate change by the forest adjacent communities.

Results: Analysis of the mean rainfall trends over the last 30 years (1980-2018) reveal that, mean monthly rainfall ranged from a monthly minimum 36mm (2012) to a maximum mean of 402.30mm (2018). Similarly, analyses of the mean monthly rainfall reveal dissimilarities in amounts of rainfall in each year over the last 30 years. The mean monthly rainfall fluctuations appear to increase overtime. Analysis of temperature records for the last 30 years (1990-2018) revealed a maximum mean daily temperature of 27.720C, a minimum temperature of 25.35⁰C and a maximum of 31.96⁰C with a range of 25⁰C - 30⁰C. From 2005 to 2018, higher temperatures (above 30⁰C) are evident. When a moving cumulative mean, using data on the minimum temperature over the last 30 years (1982 – 2018) was calculated, a forecasted trend gave a mean minimum temperature of 14.41⁰C, a minimum temperature of 12.33⁰C and a maximum temperature of 18.67⁰C. In the year 1990, the minimum temperature rose from 150C to 18⁰C. The forecasted temperature for 2019 also follows the same trend, with temperatures now stabilizing above 30⁰C. Majority of the respondents (96.7%, n=290) were aware of changes in climatic conditions now, compared to previous years. Most of the respondents had moderate (53%, n=159) to high (30.7%, n=92) knowledge about changes in climate. Majority of the respondents (57.7%, n=173 ) affirmed that information on climate change was obtained from broadcast media. Majority of the respondents were very concerned about climate change 91.7% (n=275) suggesting that they understood the seriousness of the changing climate. Further analyses of the data revealed that many of the respondents were aware that natural causes (31%, n=93), human activities (34.3%, n=103) and a combination of both (34.7%, n=104) were the main causes of climate change, while many of the respondents (58%, n=174) had experienced some extreme weather events in the last five years.

Conclusion: There is a clear evidence of climate changes in the Kakamega forest ecosystem as observed from the rising temperatures and variability in precipitation. Most people adjacent to the forests are aware of climate changes and its effects. The main sources of information are the electronic media. The increase in temperature may be due to deforestation, urbanization and agricultural activities.