The Green Review

Climate is the average weather in a particular area. Climate change, according to the IPCC, refers to the change in the mean and/or variability of temperature and precipitation over an extended period, typically decades or longer. To simply put, it is the long-term shift in the average weather conditions.   

 What causes climate change?  

The Earth’s climate is largely influenced by several factors, these include solar radiation, wind, and ocean currents. These variables interact with one another to form the climate system which interacts with other components of the Earth system to generate long term shifts in average weather. Climate change is caused by the variation in internal and/or external processes, with both natural and human actions affecting the climate system.   

 Examples of internal processes  

1. Solar radiation  

Solar outputs vary. When energy from the sun is reflected off the Earth’s surface back into space, the planet cools. Alternatively, when the Earth absorbs more energy from the sun mostly due to greenhouse gases in the atmosphere, the planet warms.  

2. Milankovitch cycles 

Collectively, the earth’s orbit, tilt, and precession form Milankovitch cycles. These influence the amount of sun that reaches the Earth’s surface. The orbit around the sun influences the length of seasons, the closer the Earth is to the sun, the warmer the climate. The tilt changes over time, as the angle increases summers become warmer and winters get colder. The precession influences seasonal contrasts between the hemispheres.  

Examples of external processes  

 1. Greenhouse gases 

There are three main greenhouse gases: carbon dioxide, methane, and water vapour. These gases trap solar radiation in the earth’s atmosphere for extended periods making the climate warmer. Human activity such as industrialization has resulted in large amounts of GHG emissions generated from burning fossil fuels.  

 2. Tectonic plates  

Movement of tectonic plates causes a change in ocean currents and creates volcanic eruptions. These changes also contribute to the increase of atmospheric greenhouse gases, therefore adding to climate change.  

 What is the impact of climate change?   

Climate models have projected that we will see more frequent and intense droughts, storms, heat waves, rising sea levels, melting glaciers and warmer oceans. The impact of climate change varies depending on the region. While warming may result in desertification in some countries, it could result in extreme flooding events in others.  

Not only does it affect human society, but it also poses serious threats to our ecosystems. In terms of the environment, forests are expected to experience more disturbances (i.e pest outbreaks, fires), therefore changing the composition of forest structures and dynamics.  

What can you do?  

The IPCC concluded that there is more than a 95% probability that over the past 50 years, human activities have accelerated climate change. Although, major changes will need to come from large companies and governments, it is still important to take individual action on climate change.  

Here are some easy and simple ways to make a high impact:  

• Eat more plant-based meals 
• Drive less
• Buy seasonal produce 
• Support local businesses   
• Reduce your consumption 
• Talk to others about climate change 

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