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Climate scientists are in nearly unanimous agreement that the Earth’s atmosphere is getting warmer. Over the next 100 years, this warming will affect the way people around the world live. Even if you know climate change matters, you might benefit from a brush-up on the basics.
Why is the climate changing?
The light from the sun that passes through our atmosphere and reaches Earth is radiated back toward space as heat. Certain gases in the atmosphere trap that outgoing heat and warm the lower atmosphere and the Earth’s surface.
One of these gases is carbon dioxide, and its levels are raised by natural events such as breathing and volcanic eruptions, but also by by human activities such as deforestation and burning fossil fuels. According to NASA, the U.S. space agency, humans have increased the atmospheric carbon dioxide concentration by a third during the last 200 years.
This is a problem because the more carbon dioxide there is in the atmosphere, the more radiated heat the atmosphere traps, making the Earth warmer. This is called the greenhouse effect.
Weather and climate: They’re not the same.
The change in climate over many years can be hard to perceive because of the way our weather changes from day to day. Some days are hotter, and some cooler. But don’t confuse weather with climate.
When people talk about the weather, they refer to day-to-day, hour-to-hour fluctuations in the atmosphere. The temperature, humidity and rainfall increase and decrease continuously depending on location and season.
When people talk about climate, they are talking about how the atmosphere behaves year-to-year or — more commonly — during decades or centuries in a particular place. Climate describes long-term patterns, and these patterns show that Earth is getting warmer.
What does climate change mean for Africa?
Although climate change will affect the whole world, Africa is especially vulnerable. South Africa, for instance, has been getting hotter during the last four decades. Average yearly temperatures there have increased by 0.13 degrees Celsius each year since 1960. According to the Intergovernmental Panel on Climate Change, if these trends throughout the continent continue:
Drought and flood events will be more frequent and more intense.
Water scarcity will increase, leaving as many as 250 million people without the water they need by 2020.
Revenues from crops will drop by as much as 90 percent in parts of the continent by 2100.
Looking toward solutions
Although the facts of climate change are daunting, there are significant opportunities to prepare for and minimize its effects. Climate Partners offers examples of ways some communities, businesses and individuals are reducing pollution. (You can also follow Climate Partners on Twitter.)