Introduction to climate change

The main goal of this lesson is to give an introduction to climate change. The following questions will be answered in this lesson:

1. What is climate?
2. What is climate change?
3. Wat is causing the rapid climate change?
4. What is the world's reaction to climate change?
5. How can we combat climate change?

Climate is defined as the long-term average of weather, typically averaged over a period of 30 years. Variables that are commonly used to describe the climate are temperature, humidity, atmospheric pressure, wind, and precipitation.

So weather and climate are not the same!

Weather: What you get Short-term Can change within minutes or hours

Climate: What you expect Long-term Takes a long time to change

Sources:  IPCC  and  NASA 

Statement 1: The clothes you are wearing today.

Statement 2: The warmest month in Kenya is March.

Statement 3: A thunderstorm is approaching, we should stay at home.

Statement 4: Next week will be extremely hot

Statement 5: The collection of clothes in your closet.

Statement 6: The average annual rainfall in Nairobi amounts to 1,000 mm.

Definition: Climate change describes a change in the average conditions — such as temperature and rainfall — in a region over a long period of time. For example, 20,000 years ago, much of the Earth was covered in ice because the average temperature was around 10 degrees Celsius lower than it is today.

Global climate change refers to the average long-term changes over the entire Earth. Earth’s climate has constantly been changing — even long before humans came into the picture. However, scientists have observed rather unusual changes recently. Earth’s average temperature has been increasing much more rapidly than expected over the past 150 years. Besides warming, signs of a changing climate include changes in precipitation, as well as other effects, such as:

• Rising sea levels.
• Retreating mountain glaciers.
• Ice melting at a faster rate than usual, especially in Greenland, Antarctica and the Arctic.
• Changes in flower and plant blooming periods.

Source:  NASA 

Which of the following options are associated with climate change?

a) Surface temperatures are setting new heat records about each year. b) More extreme weather like droughts, heat waves, and hurricanes. c) The ice sheets are declining and glaciers are in retreat globally. d) All of the answers above.

Greenhouse gases in Earth’s atmosphere block heat from escaping. This is called the greenhouse effect. These gases keep the Earth warm like the glass in a greenhouse keeps plants warm. Examples of greenhouse gases are carbon dioxide, water vapor and methane. The animation below shows the mechanism of the greenhouse effect.

Human activities are changing the natural greenhouse through the emission of more greenhouse gases. In addition, deforestation releases carbon dioxide from the forests into the atmosphere. These changes cause the atmosphere to trap more heat than it used to, leading to a warmer Earth. Carbon dioxide is the primary greenhouse gas emitted through the burning of fossil fuels and deforestation. Another important greenhouse gas is methane, which is mostly emitted through agricultural activities.

Source:  NASA 

What is the greenhouse effect?

a) The name of climate change legislation. b) When you paint your house green. c) When you build a greenhouse. d) When the gasses in our atmosphere trap heat and block it from escaping our planet.

Some parts of Earth are warming faster than others. But on average, global air temperatures near Earth's surface have gone up about 1 degrees Celsius in the past 100 years. In fact, the past five years have been the warmest five years in centuries.

Many people, including scientists, are concerned about this warming. As Earth’s climate continues to warm, droughts and heat waves are expected to become more intense. In addition, the intensity and amount of rainfall during storms such as hurricanes are expected to increase. Thus, a change in Earth’s temperature of one or two degrees can have big impacts on the health of Earth's plants and animals.

Paris agreement

In 2015, world leaders reached an agreement to combat climate change and to accelerate and intensify the actions and investments needed for a sustainable low carbon future. The Paris Agreement brings all nations into a common cause to undertake ambitious efforts to combat climate change and adapt to its effects, with enhanced support to assist developing countries to do so. As such, it charts a new course in the global climate effort.

In 2015, world leaders reached an agreement to combat climate change and to accelerate and intensify the actions and investments needed for a sustainable low carbon future. The Paris Agreement brings all nations into a common cause to undertake ambitious efforts to combat climate change and adapt to its effects, with enhanced support to assist developing countries to do so. As such, it charts a new course in the global climate effort.

The Paris Agreement’s central aim is to strengthen the global response to the threat of climate change by keeping the global temperature rise this century well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius. There are now 186 countries that have ratified the Paris Agreement.

Sources:  NASA  and  United Nations 

What was agreed to in the “Paris Agreement” that came out of COP-21, held in Paris in 2015?

a) To limit sea level rise to 3 feet above current levels. b) To pursue a goal of 100% clean, renewable energy. c) To protect biodiversity and end the deforestation of the world’s rainforests. d) To keep global temperature rise well below 2℃ pre-industrial levels and to pursue a path to limit warming to 1.5℃.

The future effects of climate change can be reduced through mitigation and adaptation. Mitigation reduces emissions and stabilizes the levels of greenhouse gases in the atmosphere. This can be done by, for example, the transition towards renewable energy sources, regenerative agriculture and reforestation.

On the other hand, adaptation focuses on the adjustment to actual or expected future climate. Examples of adaptation include building flood defenses, transforming towards climate resilient cities and developing drought-tolerant crops. This tailor-made training focusses on climate change adaptation and in particular how the agricultural sector can adjust to the effects of climate change. This is called ‘Climate smart agriculture’.

Source:  NASA 

Measure 1: Reforestation.

Measure 2: Installing a solar water heater.

Measure 3: Improving the quality of road surfaces to withstand hotter temperatures.

Measure 4: Developing drought-tolerant crops.

Well done! you have completed the first lesson of module 1. Now you can continue with the second lesson. The answers to the exercises can be found below.

1. Weather
2. Climate
3. Weather
4. Weather
5. Climate
6. Climate

Answer d

Answer d

Answer d

1. Mitigation
2. Mitigation
3. Adaptation
4. Adaptation