Climate Change: Causes, Effects and Solutions

1Physical features shape the climate

• Mountains force wet winds to rise. The air cools and drops rain on the side facing the wind (relief rain). The far side, called the rain shadow, is drier.
• Lakes such as Victoria and Kivu give moisture to the air, so the land around them gets more rain and thunderstorms.
• Forests such as Nyungwe and Gishwati release water vapour that helps make rain, and their shade keeps the land cooler.
• Altitude keeps high places cool.

So when people cut down forests or drain wetlands, they change the local climate too: less rain in some places, hotter days, and more water rushing off bare hills.

2What is climate change?

Climate change is a long-lasting change in the usual weather patterns of a place or of the whole Earth, such as its temperature, rainfall and winds. Today the biggest change is global warming: the Earth's average temperature is rising.

3Why is the Earth warming?

Some gases in the air, such as carbon dioxide and methane, trap the Sun's heat like a blanket around the Earth. They are called greenhouse gases. A thin blanket keeps the Earth warm enough for life. But people are making the blanket thicker by:

• burning fossil fuels (petrol, diesel, coal and gas) in cars, factories and power stations;
• cutting down and burning forests for farms, firewood and charcoal (trees normally take carbon dioxide out of the air);
• draining wetlands and burning bush;
• leaving piles of rotting rubbish, and keeping very large herds of cattle, which both give off methane.

4Effects of climate change in Rwanda

• Heavier rain, floods and landslides on steep hills in the west and north, as in May 2023 in Rubavu, Rutsiro, Nyabihu, Ngororero and Karongi.
• Longer dry spells and droughts, especially in the Eastern Province, so crops dry up.
• Food shortages and higher food prices when harvests fail.
• More disease: warmer weather lets malaria mosquitoes live higher up the hills than before.
• Soil erosion, which washes fertile soil into rivers. That is one reason the Nyabarongo and the Sebeya often look brown.
• Damage to houses, roads, bridges, schools and power lines.
• In East Africa, the ice on top of Kilimanjaro, Mount Kenya and the Rwenzori is shrinking.

5What Rwanda, and you, can do

• Plant and protect trees. Every year Rwanda holds a national tree planting season during the rains. Trees on hills hold the soil, and fruit trees planted among crops (agroforestry) give food too.
• Dig terraces and trenches across steep slopes, so rainwater soaks in instead of rushing down and carrying soil away.
• Protect wetlands and riverbanks. Do not farm or build right beside rivers and lakes. Wetlands soak up floodwater like a sponge; Kigali restored the Nyandungu wetland as an eco-park.
• Harvest rainwater from roofs into tanks. This gives water in the dry season and means less water rushing downhill.
• Move families away from high-risk zones on very steep slopes and in flood plains.
• Use cleaner energy: solar power, hydropower, gas, or improved cookstoves that burn less charcoal. Walk, cycle, or use electric motos and buses.
• Reduce waste: Rwanda banned plastic bags in 2008. Reuse and recycle.
• Follow weather warnings from Meteo Rwanda (the Rwanda Meteorology Agency) and move to safety when heavy rain is forecast.

Rwanda's environment agency, REMA, follows a national plan called the Green Growth and Climate Resilience Strategy (2011).

Try it yourself