IB DP Biology Climate change Study Notes
IB DP Biology Climate change Study Notes
IB DP Biology Stability and change Study Notes at IITian Academy focus on specific topic and type of questions asked in actual exam. Study Notes focus on IB Biology syllabus with guiding questions of
- What are the drivers of climate change?
- What are the impacts of climate change on ecosystems?
Standard level and higher level: 3 hours
Additional higher level: 1 hour
D4.3.1—Anthropogenic causes of climate change
- Greenhouse Effect: The Earth’s atmosphere traps heat from the sun, similar to how a car parked in the sun gets hot. This is known as the greenhouse effect.
- Greenhouse Gases: Methane and carbon dioxide are key greenhouse gases.
- Human Activities: Burning fossil fuels (like coal, oil, and gas) and deforestation are major sources of greenhouse gas emissions.
- Global Warming: Increased greenhouse gases trap more heat in the atmosphere, leading to a rise in global temperatures.
- Climate Change Impacts: This warming affects weather patterns, including increased frequency and intensity of extreme weather events.
D4.3.2—Positive feedback cycles in global warming
Key Points:
Melting Ice and Albedo: Snow and ice have a high albedo, meaning they reflect a lot of sunlight back into space. As polar ice and sea ice melt, more of the Earth’s surface is exposed, which absorbs more heat. This leads to further warming and accelerated ice melt.
Permafrost Melting: Permafrost contains large amounts of organic matter. As permafrost thaws due to rising temperatures, this organic matter decomposes and releases methane, a potent greenhouse gas. This further contributes to warming and accelerates permafrost thaw.
Ocean Warming and Carbon Dioxide Release: As global temperatures rise, the temperature of the oceans also increases. Warmer water can hold less dissolved carbon dioxide. This leads to the release of more carbon dioxide from the oceans into the atmosphere, further amplifying warming.
These positive feedback cycles create a self-reinforcing process where warming leads to changes that accelerate further warming. They are a significant concern as they can make it more difficult to mitigate the effects of climate change.