Lesson 1.1: What is Climate Change?
By definition, The Intergovernmental Panel on Climate Change (IPCC) describes climate change as “ The A change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcing, or due to persistent anthropogenic changes in the composition of the atmosphere or land use".
Climate change is generally considered as the change in the weather condition of a particular region when considered over 30 years or three decades.
Climate change is characterized by the following;
Rising temperatures - this is characterized by average global temperatures.
Changing precipitation patterns - this is a variation of weather events that can result in extreme floods or droughts.
Extreme weather events - more intense weather events.
Droughts - prolonged periods of water shortages.
Floods
Climate change has adverse effects on the health, environmental and also agriculture sector.
The adverse effects of climate change include:
Health impacts: Increased incidence of respiratory problems, skin diseases
Environmental impacts: Disruption of ecosystems, loss of biodiversity
Agricultural impacts: Altered crop yields, reduced productivity, and increased risk of crop failures and livestock death.
NB: It is important to note that weather is different from climate. Weather is short atmospheric conditions while climate is long term average of weather patterns.
Factors contributing to climate change
Over the decades, several natural causes have been recorded as the main drivers of climate change. However, there has been noted a faster increase in the mean global temperatures not attributable to natural occurrences. Research has revealed that anthropogenic activities are the key drivers of these changes.
This clearly shows that human activities are contributing majorly in greenhouse gasses than the natural causes.
The human activities include:
Industrial processes
Deforestation
Burning of fossil fuels
Agriculture practices such as enteric fermentation, animal manure, use of synthetic fertilizers
Disposal of wastes (landfills)
Land degradation
Lesson 1.2 Greenhouse gasses(GHG) and their contribution to global warming
Definition of GHG; They are gasses found in the earth’s atmosphere that trap heat and contribute to the greenhouse effect.
They are also referred to as heat trapping compounds.
Major greenhouse gasses (GHGs) include water vapor, carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and fluorinated gasses.
In normal concentrations, these gasses contribute to the natural greenhouse effect, which is essential for maintaining Earth’s temperature. However, when GHG concentrations increase primarily due to human activities, they intensify the greenhouse effect, leading to harmful global warming and climate change.
Greenhouse effect is a natural process where GHG gasses in the Earth’s atmosphere trap heat from the sun. This process begins when the sun's energy, in the form of ultraviolet radiation, reaches the Earth’s surface, warming it. The Earth then radiates this energy back into space as infrared radiation. While some of this heat escapes, greenhouse gasses absorb and trap part of it, warming the atmosphere and, in turn, the Earth and oceans.
Global warming occurs due to the rise of GHG gasses in the atmosphere. It refers to the long-term rise in average surface temperature due to the enhanced greenhouse effect caused by increased concentrations of greenhouse gasses in the atmosphere. This ongoing warming trend is leading to climate change.
