IB Biology Sub-topic D4.3 Notes

You are likely familiar with climate change as a concept, and need to know more about it in this topic. It is defined as an extreme change in climate conditions due to changing global conditions. This disruption to our climate is commonly attributed to human activity. However, there is still opposition to this so let's review the evidence for and against climate change.

1. Drilling into ice from thousands of years definitively shows a strong association between atmospheric carbon dioxide and global temperature.
2. Natural processes such as Milankovitch cycle, sunspot activity, ocean currents, and volcanoes all contribute to the climate.
3. Carbon dioxide has naturally fluctuated throughout history due to shifting tectonic and volcanic activity.
4. Additionally, global warming does not increase uniformly whereas carbon dioxide concentration does.
5. However, carbon dioxide concentration has drastically increased since the 1950s at a historic rate.
6. This coincides with the additional mass burning of fossil fuels by humans, and the associated increase in temperature.

There is extensive denial on this evidence due to conflicting interests, especially from companies that profit from fossil fuels. However, all the evidence has been analysed by many climate change scientists, who have almost unanimously concluded that climate change is an anthropogenic process.