SAJC Cluster 3.2 Lecture 11 notes (Possible Effects of Contemporary Climate Change (I):)

St Andrew’s Junior College H2 Cluster 3: Sustainable Future and Climate Change H2_Cluster 3 Lecture 11_2025/pg1 Lecture 11 Possible Effects of Contemporary Climate Change (I): Impacts on Ecosystems and Humans KEY QUESTION: How will contemporary climate change impact humans? Will contemporary climate change impact everyone in the same way? With the completion of this lecture, attached readings and tutorial, you should be able to understand the: • Changes in temperature and precipitation associated with contemporary climate change • Impacts of contemporary climate change on aquatic and terrestrial ecosystems • Impacts of these changes in aquatic and terrestrial ecosystems on humans • Impacts of contemporary climate change on places • Variation in negative impacts of contemporary climate change Lecture Overview 11.1 Changes in Temperature and Precipitation associated with Contemporary Climate Change (a) Temperature (b) Precipitation 11.2 Impacts of Contemporary Climate Change on Ecosystems (a) Terrestrial ecosystem (b) Aquatic ecosystem Box 1: Contemporary climate change and its impacts on walruses 11.3 Impacts of Changes to Ecosystems on Humans 11.4 Positive and Negative Impacts of Contemporary Climate Change on Places 11.4.1 Melting Ice Sheets and Sea Level Rise (SLR) 11.4.2 Extreme Weather – (a) Desertification and Drought (b) Storms and Cyclones 11.4.3 Human Health 11.4.4 Migration of Populations 11.4.5 Crop Yields 11.4.6 Trade Routes 11.4.7 Tourism 11.5 Variations in Negative Impact of Contemporary Climate Change 11.5.1 Variations in Negative Impacts of Contemporary Climate Change due to Places 11.5.2 Variations in Negative Impact of Contemporary Climate Change due to Differences in Vulnerability of Different Groups of People 11.6 Conclusion Readings – The following are recently published summaries of the impacts observed in world regions most relevant in our syllabus: 1) Geofile 770, January 2018: See the Great Barrier Reef before you die … or before it dies? 2) IPCC AR6 (2022) Factsheet – Asia 3) IPCC AR6 (2022) Factsheet – Africa 4) IPCC AR6 (2022) Factsheet – Small Islands

St Andrew’s Junior College H2 Cluster 3: Sustainable Future and Climate Change H2_Cluster 3 Lecture 11_2025/pg2 11.1 Changes in Temperature and Precipitation associated with Contemporary Climate Change • In Lecture 10, we learnt that the enhanced greenhouse effect has led to an increase in heat that is retained on Earth, bringing about an increase in global average temperatures. The rise in temperature influences precipitation. Together, the increase in temperature and precipitation changes are expected to generate potentially devastating impacts on natural systems and humans as a result. (a) Temperature • As we have learnt in earlier lectures, the increase