Climate change has no human face. It is a disrupter of natural ecosystems. Its regional patterns and impacts create disproportionate risks to the worldwide environment and human well-being. The July 2025 strategic framework document of African Centres for Disease Control and Prevention notes that across the globe, “climate change is projected to cause an additional 14.5 million deaths, over 2 billion healthy life years lost and $12.5 trillion in economic losses by 2050.” It further reveals that 56% of over 2,000 public health issues examined between 2001 and 2021 in Africa are climate change-induced.
For clarity, climate change is driven by rising temperature which manifests as global warming. Global warming is caused by greenhouse gases emitted to the atmosphere. In his book, How to Avoid Climate Disaster, Bill Gates records that fifty-one (51) billion tons of greenhouse gases were cumulatively added to the global atmosphere before the 2020 COVID-19 lock-down. Emitted greenhouse gases trap heat in the atmosphere and in turn, warm the earth’s surface temperature. So, with more emissions, the global temperature rises higher. And since the year 1850, emissions of greenhouse gases have remained on a dramatic increase.
Carbon dioxide (CO2) is a major greenhouse gas with about 74% of the global overall. Despite the stronger potency of emitted gases from methane (CH4) and nitrous oxide (N20), CO2’s higher concentration and long stay in the atmosphere makes it the core driver of human-induced climate change. Thus, about “one-fifth of the carbon dioxide emitted today will still be there in 10,000 years.” CO2 is generated from human activities such as burning of fossil fuels, industrial byproducts, deforestation, and certain agricultural practices (enteric fermentation during livestock digestion and anthropogenic methane in flooded rice paddies).
Water vapour is also a greenhouse gas, but it stays for a while in the air and falls back as rain or snow to the earth’s surface. The natural sources of greenhouse gases like volcanic eruptions, respiration, decomposition, and emissions from oceans and wetlands do not pose the level of risk as human-induced greenhouse gas. The knock-on effects of rising temperature could precipitate a frequency of hurricanes, wildfires, and flooding, just as increased evaporation can lead to heavier rainfall and flooding.
As an indicator of climate change, sea level rise is in two domains. The first is the expansion of waters. When oceans warm up, they increase in volume. The second is the melting of land ice, that is, mountain glaciers. The big ice sheets in Greenland and Antarctica contribute significantly to the rising of sea level. However, the revelation that in the last 2,000 years, sea level was stable but by the late 19th century, it began to rise continually, is worrisome. Notwithstanding, scientific prediction holds it that it would continue up till the year 2100, as big ice sheets do
not speedily respond to changes in temperature.
Climate change also manifests as heat extremes. In the last four decades, more areas of the planet earth have been affected up to ten times. The air is hotter and holds back more moisture. Drought sometimes, is a logical outcome. Sub-Saharan Africa (SSA) has witnessed drought, flooding and intense storms with vulnerabilities for human and the economy. The changing patterns of rainfall leads to increased aridity. And since SSA relies mainly on rain-fed agriculture, livestock farming and crop production are heavily affected. The drought within the Sahelian belt exacerbates food insecurity. Blue Water Intelligence posits that “two-thirds of armed conflicts take place in arid regions, making equitable resource distribution crucial.”
Virtually all countries and regions of the world are directly or indirectly impacted by climate change. From Gates’ book, the southwestern part of United States would witness a 20% rise of drought by the end of this century, while the Colorado River, which supplies drinking water to 40 million people and irrigates one-seventh of American crops is seriously threatened. On the other hand, southern Africa would record less frequent rainfall. There is also a prediction that the Horn of Africa would get wetter, with its gains and drawbacks.
The intensity of ocean acidification by about 30% since the Industrial Revolution affects the planet and organisms in the sea. A senior scientist, Carol Turley, notes that a carbonic acid is formed when CO2 is added to sea water which absorbs 25% of CO2 emitted to the atmosphere. Coral reefs and marine calcifiers are hindered from accessing calcium carbonate from the sea water. Besides, the vast coastlines in SSA are already impacted by sea level rise. Recently, the Nigeria Meteorological Agency (NiMet) issued an alert to residents of floodplains in 20 States in the country to avert the imminent flooding by relocating and taking other necessary measures. In the long run, building of homes or setting up of businesses in the flood-prone areas should be prohibited with empathy and government support, and thereafter, criminalized.
Indeed, mankind faces an existential threat from climate change. Africa, a poor continent, which contributes about 2% of global greenhouse gases, bears the brunt too. The attendant catastrophe would overwhelm humanity if left unchecked. But the unfortunate reality is that “as people rise up the income ladder, they do more things that cause emissions.” Under the Paris Agreement, countries are expected to submit their National Determined Contributions (NDCs), which are national climate action plans. The first step would be to initiate a long-term policy that incentivizes reduction in CO2 emission.
Nations are encouraged to transition to renewables in electricity and automobiles.
The idea of climate smart agriculture for increased resilience of farming system is a welcome development. Efficient management of water systems in areas under the threat of water insecurity is instructive. By policy and law, countries should be encouraged to maintain their forests. Nigeria has a less impressive deforestation record globally. Therefore, the practice of agroforestry is critical. Deploying early warning systems will help to mitigate emerging conflicts. More importantly, the welfare of the world’s poorest who contributed little or nothing to the problem, should be on the front burner.
