Back to: Environmental Biology 200 Level
Welcome to class!
Hello superstar! I’m thrilled to see you again. Have you noticed how our weather seems to be changing — hotter days, sudden heavy rain, or even harmattan coming late? These changes are part of what we call climate variability, and they affect how plants, animals, and humans live. Today, we are learning about Climate Variability & Ecosystem Responses — and by the end of this lesson, you will understand how our ecosystems react to changes in the climate around them.
Climate Variability & Ecosystem Responses
What is Climate Variability?
Climate variability means the natural changes in weather patterns over months, years, or decades. It is different from climate change, which refers to long-term shifts caused by human activities. In Nigeria, climate variability can be seen when the rainy season starts late in some years or when there is heavier rainfall than usual.
Causes of Climate Variability
Natural factors: Ocean currents, volcanic eruptions, and changes in the sun’s energy.
Human factors: Deforestation, burning of fossil fuels, and greenhouse gas emissions.
Seasonal changes: Natural shifts like the El Niño and La Niña events affect rainfall and temperature worldwide.
Effects of Climate Variability on Ecosystems
Ecosystems depend on stable weather patterns. When the climate varies too much, the balance is disturbed:
Plants: Prolonged droughts can make crops like maize or millet fail.
Animals: Changes in temperature affect breeding or migration. For example, birds may migrate earlier or later than usual.
Water bodies: Rivers and lakes may dry up, affecting fish populations. Lake Chad’s shrinking size is a good example in Nigeria.
Forests: Excessive heat and reduced rainfall increase the risk of wildfires in dry regions.
Ecosystem Responses
Ecosystems try to adapt to changing conditions. Some plants grow deeper roots to find water, while animals may move to cooler areas or change feeding habits. However, when the changes are too extreme, some species may die off, leading to reduced biodiversity.
Human Impact and Adaptation
Human activities worsen climate variability. Cutting down trees reduces shade and rainfall, while burning fuels increases global warming. To adapt, we must:
Plant trees to stabilise rainfall and temperature.
Use irrigation to support farming during droughts.
Protect wetlands, which act as natural buffers against floods.
Use renewable energy sources like solar to reduce greenhouse gases.
Examples in Nigeria
In the north, farmers now plant drought-resistant crops like sorghum because of unpredictable rainfall. In coastal regions like Lagos, rising sea levels and flooding have pushed people to build stronger drainage systems.
Summary
- Climate variability is the natural change in weather patterns over time.
- It affects plants, animals, water bodies, and forests.
- Ecosystems respond by adapting, but extreme changes can cause loss of species.
- Humans can reduce harmful effects by planting trees, conserving water, and reducing pollution.
Evaluation
- Define climate variability and give one Nigerian example.
- Mention three effects of climate variability on ecosystems.
- How can farmers adapt to unpredictable rainfall?
- Suggest two ways humans can reduce the impact of climate variability.
Fantastic job today! Always remember that protecting our environment helps reduce climate challenges. You are a climate hero in the making, and Afrilearn is here to guide you every step of the way.