Climate Change in Southern Tanzania and Zanzibar

"Assessing climate change effects at the country level is tricky. The averaging approach is widely applicable because it is easy to calculate; however, it is useless in practice. Different climate zones may respond to climate change in opposite directions, and such a pattern alternates from year to year," says Elena Surovyatkina. This is particularly true for a country like Tanzania that has the Indian Ocean coastal area, tropical savanna, and mountains. Surovyatkina's expedition aimed to reveal the areas most vulnerable to climate change.

 Small island Zanzibar is particularly at risk. Sea level rise leads to salty seawater increasingly penetrating inland areas and destroying rice plantations. Rising ocean temperatures force fish to abandon their historical territories close to the coast and move to cooler waters far away in the ocean. Combined with plastic trash in the ocean, it also affects corals, which begin to bleach and die. Moreover, wave magnitude increase makes fishing dangerous and even impossible. To predict the start of the rainy season is difficult, because the rainy season onset varies within a month from year to year.

 Another most affected region by climate change is Southern Tanzania, located in the coastal belt of the mainland in a low elevation zone between the mountain region and the Indian Ocean coastline. It corresponds to the Savanna climate zone – tropical grassland with scattered bushes. Droughts within several months after the rainy season are becoming more frequent, severe, and pervasive. The region is a conservation area uninhabited by people but is home to an enormous animal populace. Climate change disrupts the rainy season, leading to extreme droughts and unpredictable water availability, exacerbating animal survival conditions.

 The tribe of Maasai is one of the most culturally distinctive and vibrant indigenous societies in Africa and very vulnerable to climate change. Over the centuries, the semi-nomadic Maasai have employed a green approach to land management: migrating seasonally across large swaths of territory, leaving the land plenty of time to recover before returning to graze it again. Drought is the biggest challenge for them, too, because it decreases their lands and the ability to roam from pasture to pasture to graze their animals. Nonetheless, migrating with the rainy season has proven to be the best adaptation strategy over the centuries.

 For the last three years, PIK scientist Elena Surovyatkina has predicted the onset and withdrawal of the rainy season in Southern Tanzania more than a month in advance. The unique forecast accounts for climate change effects, making it reliable to use for agriculture, livestock, and fisheries. It is the most awaited news for Tanzania because the planting and fishing start with the beginning of a rainy season, and the end of the season is a time for a Great migration.