A recent report by the World Meteorological Organisation (WMO), released on March 23, warned that global temperatures have risen to about 1.43 degrees Celsius above pre-industrial levels, underscoring intensifying climate risks worldwide.
In Nigeria, where heatwaves, erratic rainfall and flooding are becoming more frequent, scientists say the global trend is already reshaping local realities. The Nigerian Meteorological Agency (NiMet) has also flagged shifting weather patterns and increasing variability in rainfall across the country.
In this interview with HeapNews, Prof. Ilemobayo Oguntimehin, a professor of Environmental Dynamics and Management at Olusegun Agagu University of Science and Technology, explains how global climate signals are translating into tangible risks for Nigeria’s regions, cities and agricultural systems.
Q: Nigeria is already experiencing intense heat waves,How does the global 1.43°C rise translate locally across regions like the Sahel,middle Belt and coastal south?
A: The WMO findings are very important, and I also commend NiMet for localising this information. What we are seeing now did not start today, it has been building over the last two to three decades.
The rise in temperature is linked to greenhouse gases like carbon dioxide, which act like a blanket around the Earth. Imagine a room with a window: normally, heat comes in and goes out. But if you cover that window with a thick curtain, heat gets trapped. That is what is happening globally. In Nigeria, this translates differently across regions. In coastal areas like Lagos, rising temperatures contribute to sea-level rise and flooding. In the Sahel and northern regions, where rainfall is already low, the heat intensifies drought conditions.
We are also seeing changes in rainfall patterns. The traditional cycle, with a rainy season from March to September and a dry season from October to February, is no longer consistent. This affects agriculture and water availability.
Q: Are we seeing evidence that Nigeria is entering a “new normal” of extreme heat?
A: The heat is clearly more intense, and people often call it the “new normal.” But I would be cautious with that term. What we are seeing is a serious shift that demands attention.
Conditions vary across the country. What is considered extreme in Lagos may differ from what people experience in the north. In northern regions, we are already seeing cases of heat stress, which is very concerning.
If we do not change how we interact with the environment, the situation will worsen. So, rather than accept it as normal, we should see it as a warning sign.
Q: What does the data show over the past decades?
A: The data clearly show rising temperatures, increased rainfall variability, and more extreme weather events. Coastal areas are experiencing more rainfall and flooding, while inland areas are seeing declining rainfall, leading to drought and desertification.
There are projections that Nigeria’s average temperature could rise from about 28°C to around 32°C by the end of the century. That is a significant increase.
Sea-level rise is another concern. For example, in Lagos, located along the Gulf of Guinea, the rate of sea-level rise has nearly doubled in recent years from about 2.65 millimetres per year in earlier decades to around 4.75 millimetres more recently. For a low-lying coastal megacity, even small increases have serious consequences, including flooding, erosion, infrastructure damage, and saltwater intrusion into groundwater.
Nigeria’s ranking on the global disaster risk scale is also worsening slightly, which shows that vulnerability is increasing.
Q: Which Nigerian cities are warming the fastest and why?
A: Urban centres like Abuja and Lagos are warming faster due to population growth and urbanisation. Increased transportation, industrial activities and energy use all contribute to higher emissions.
In the north, desertification is pushing conditions southward. States like Kogi are beginning to feel these effects. These environmental changes can also contribute to migration and even security challenges, as people move in search of better conditions.
Q: The WMO report links warming to heavier rainfall. Is this why flooding in states like Bayelsa, Kogi and Lagos is becoming more severe?
A: Yes, there is a direct link. Higher temperatures lead to increased evaporation and more moisture in the atmosphere. This can result in heavier rainfall events.
At the same time, rising sea levels mean that coastal flooding becomes more severe. So, when you combine these factors, you see why flooding is becoming more frequent and intense.
Q: How is climate change altering the rainfall calendar for farmers?
A: The rainfall calendar has become unpredictable. NiMet provides forecasts, but variability has increased significantly.
Farmers who used to plant maize in March or April now face uncertainty because the rains may come late or stop early. This disrupts planting and harvesting cycles.
Climate change is also affecting crop yields. For example, a one-degree increase in temperature can reduce maize yields by about 10%. Increased carbon dioxide levels can reduce the nutritional quality of rice. Relatively drought-tolerant cassava is being affected by extreme conditions.
Q: The WMO introduced the concept of Earth’s energy imbalance. How can Nigerians understand this simply?
A: It is about the balance between incoming and outgoing energy. Normally, the energy from the sun that enters the Earth should be equal to what leaves.
But greenhouse gases trap some of that energy, creating an imbalance. Using a simple example: if you sit in a room and cover the window with a thick curtain, heat builds up inside. That is exactly what is happening to the Earth.
This trapped heat leads to warming, melting ice, rising sea levels and ultimately more flooding and extreme weather.
Q: Is there local data showing how this imbalance is affecting West Africa?
A: Yes, Nigeria has data showing rising temperatures and changing rainfall patterns. The projections I mentioned earlier, an increase from 28°C to 32°C, are part of that evidence.
The northern regions are likely to face the most severe impacts, including heatwaves, reduced agricultural productivity and socio-economic disruptions.
Q: What climate-smart agricultural practices should Nigerian farmers adopt urgently?
A: There are several key approaches. First, farmers should adopt improved crop varieties that are drought- and disease-resistant. Institutions like the International Institute of Tropical Agriculture (IITA) have developed many of these.
Second, soil and water management practices such as mulching can help retain moisture and protect crops from heat.
Agroforestry is also important, planting crops alongside trees to reduce heat exposure. Irrigation, including modern systems that can be controlled remotely, should be encouraged. Finally, cooperative farming and conservation agriculture, such as intercropping and cover cropping, can help farmers adapt to changing conditions.
As global climate indicators continue to worsen, experts say Nigeria’s challenge will be translating scientific warnings into practical action, from urban planning to agriculture.
“The information is available,” Oguntimehin said. “What matters now is how we respond to protect livelihoods and the environment.”