Why southern Nigeria has experienced no harmattan since December

• Don warns against looming food scarcity, hunger

A university lecturer, Prof Didacus John Njoku, has been explaining why there was no harmattan in the December 2025/ January 26 harmattan season, attributing the development to the famed climate change.

In a chat with COSMAS OMEGOH, the Professor of Tropical Climatology and Remote Sensing, and former dean, School of Environmental Sciences, at the Federal University of Technology, Owerri (FUTO), warned of possible food insecurity in the days ahead.

He urged the Federal Government to urgently encourage a move away from climate-fed agriculture to smart-weather agricultural practices to avoid the dangers associated with climate change.

Why has there been no harmattan in southern Nigeria?

There are factors that brought about this scenario. Among them is atmospheric circulation of winds – movement of high-level winds that are being variated due to climate change.

With the said scenario, there was bound to be disruption in wind flow leading to what we have as poor Harmattan.

We need to note that temperature and pressures are the drivers of weather/climate. If the temperature of a particular region is high, the pressure there is bound to be low. Conversely, if the temperature of an area is low, the pressure there will surely be high.

Usually, harmattan emanates from the area around the Sahara Region driven by the North East Trade wind drifting towards the coast of West Africa.

Now, if the pressure up there is high enough, the North East Trade wind will help the harmattan to push to the coast. But if the pressure is not high enough, that will peter away somewhere around the northern region, without its influence reaching the South.

Now, there is also another wind called the South West Trade wind which pushes from the South up North. It emanates from the Atlantic Ocean; it is maritime in nature.

Both winds push with a lot of strength. Their point of meeting is where we call the Inter-tropical Convergence Zone.

At their clashing point, if the North East trade at this time of the year is able to push the South Westerly wind downwards with a lot of strength, we are sure to have harmattan in the South.

But if the South Westerly wind is able to hold the North East Trade wind from prevailing in the South, there will be some kind of stagnation like we are experiencing now in the South.

So, we are experiencing variation in climate, basically driven by temperature which in turn drives the pressure of the winds.

Before now, we have done a lot of studies in the South-East and found out how human activities like paving of neighbourhoods, roads and all of that drive up the daily  temperature. This diurnal temperature in turn affects what is coming from the North as easterly wind. And what that means is that the increase in temperature we are having covertly affects the entry of the North Easterly wind which is understood as harmattan. What we are saying here is that urbanisation is part of the problem.

If the Sahara Region is of high pressure, in other words the temperature there is low, and the southern part has high temperature with low pressure, you see that when the air temperature rises, it will cause some kind of agitation of the air molecules. These air molecules will tend to obscure or will not be receptive to the entry of the cold wind. It warms it up and when this happens, there won’t be any harmattan. We will experience a kind of weather that is neither sunny nor cold.

Why this type of scenario?

What is happening now is a variation because when we were growing up, we knew that the moment the last rains fell in November, they would usher in the harmattan which would always prevail up to January-ending before petering away. The dry season then would continue till March. Then the wet season set in April.

However, what is happening now, though scientific, is not strange even in the way it affects lives. To scientists and even those at the meteorological centre, NIMet, it may not be completely strange. This is because most of the things we do here are dependent on the weather – not to talk about agriculture; everything is climate-dependent – including our health.

People wonder at what is going on, but sadly our collective human activities are contributory to that. We all are contributing to the weather variation we are noticing.

Would harmattan return later in the year?

Well, the harmattan can possibly return in the days ahead because the situation is unpredictable. That can possibly happen if the South Westerly wind fails to abort the advance of the North Easterly wind. If the local factors in the South disallow its push to the coastal areas, the move will be halted.

To scientists, the scenario is not strange. But to locals whose activities depend on this interplay, it is a surprise.

We need to note that even the usual August break has varied for some time now. Yet, our mindset is that the break still happened in the same August. But things are changing.

Is climate change at work?

It is the variability of the climate that brings about what we now know as change. We have been warned that the climate will continue to vary. There will be climate change induced by human activities.

The warning out there is that if we don’t change our ways, our activities will continue to affect the atmospheric conditions which will in turn put pressure on our environment. If we don’t go natural, the climate will continue to vary; that will not abate in time to come.

How does the current scenario affect the environment?

What is going on will certainly affect agriculture adversely. For instance, the first and second rains have fallen in Owerri this year. Now, if a farmer goes ahead to plant yam based on the rains, guess what will happen.

Again, if a farmer keeps his seed yam till April, when is he going to plant and harvest? What will the people eat?

So, we can see that the commencement and cessation of rainfall are factors in our food production. So, all that affects agriculture adversely.

If the rain does not come sufficiently, there will be poor germination of seeds. We will have dry and decaying seeds. If the rains come early, what about people who use open spaces to store their seed yams? Perhaps, the yams will rot away.

With regard to human health, there are pathogens that develop during the dry season. All that will affect health, which will in turn impact human activities. Talk about those farmers who harvest and sell for their economic well being. There will be nothing to harvest and nothing to sell.

Studies have confirmed that crops like cassava, rice and yam have favourable conditions that induce maximum productivity. But here, when we plant, we leave it to nature. When those conditions are not met particularly during the growing season, there will be poor harvest. Then  food insecurity flows.

What are the things that need to be done?

It has been said that the prevailing conditions will certainly impact food security. When we add that to all other human factors: insecurity in particular, you will know that people are likely going to face hunger in 2026.

Having said that, the clear warning now is: we must begin to move away from rain-fed agriculture to smart agricultural practices. We need to move away from weather-dependent agriculture. We must seek to monitor the weather, determine the amount of temperature we want and the amount of precipitation we want in that environment. We need to modify the weather. That is called climate-smart agriculture. We can begin to do that starting with Obasanjo Farms, the UAC Farms and other large farms. We need to begin to experiment with them.

We must note that advanced countries don’t depend on rain-fed agriculture anymore; so we need to move fast.

We need to begin now to develop our agricultural practices, starting with a gradual move away from weather- dependent agriculture. When we move away from depending on climate for our agriculture, health and construction, we will be setting our own standards.

Now, the situation is no longer funny. Consider that in Maiduguri we are having a temperature of 42’-46’C, something that has never happened before. So, if there is low moisture, will crops grow? What will happen?

That will also mean that rising temperature in the North will make it impossible for vegetation to grow.

If there is insufficient moisture in the soil, grasses will disappear; yet, the fodder the animals are fed are grass-based.

Sadly, the said situation is expected to grow worse. The weather is still varying; and that is why it is called climate change. So, we shouldn’t allow it to get out of hand.

That is why we need to note that what is going on now is not going to affect agriculture alone, it will affect human health too. It will also affect productivity. When it rains too much, the humidity in the air will induce certain illnesses. There might be water-borne diseases. When it fails to shine, human health too will be affected. Some people will be affected psychologically, thinking that the world is coming to an end. If the dry season is excessive too, there will be respiratory diseases and others induced by dryness. People will frown in the hospitals while the doctors will smile to the banks.