OCR GCSE Geography B: Changing Climate Tutorial

Contents

1. Introduction to Changing Climate
2. Evidence for Climate Change
3. Natural Drivers of Climate Change
4. Enhanced Greenhouse Gases
5. Impacts of Climate Change
6. Responsibility Debate
7. Conclusion

Introduction to Changing Climate

Climate change refers to significant and lasting changes in Earth's climate patterns, particularly an increase in global temperatures. This tutorial explores the evidence, drivers, impacts, and responsibilities associated with climate change.

Evidence for Climate Change

Key evidence supporting climate change includes:

• Ice Cores: Reveal historical CO₂ levels through trapped air bubbles.
• Sea-Ice Extent: Observations show declining Arctic and Antarctic ice.
• Temperature Records: Global temperatures have risen steadily since the Industrial Revolution.
• Glacier Retreat: Glaciers worldwide are shrinking at an unprecedented rate.
• Sea-Level Rise: Oceans are rising due to thermal expansion and melting ice.

Natural Drivers of Climate Change

Natural processes contribute to climate variability:

• Milankovitch Cycles: Changes in Earth's orbit affect solar radiation distribution.
• Solar Output: Variations in the Sun's energy output influence Earth's temperature.
• Volcanic Eruptions: Release gases like CO₂ and aerosols, impacting climate.

Enhanced Greenhouse Gases

Human activities have increased greenhouse gas concentrations:

• CO₂: Largest contributor, primarily from fossil fuels.
• CH₄: Potent gas with high global warming potential (GWP).
• N₂O: Released from agriculture and industrial processes.
• Halocarbons: Include fluorinated gases with very high GWPs.

Potency and Proportions

Impacts of Climate Change

Global Impacts

• Heat Extremes: Increased frequency and severity of heatwaves.
• Sea-Level Rise: Threatens coastal communities and ecosystems.
• Food Stress: Changing weather patterns disrupt agriculture.
• Ecosystem Disruption: Loss of biodiversity and habitat destruction.

UK Impacts

• Heatwaves: Summer temperatures are rising, posing health risks.
• Sea-Level Rise: Coastal erosion and flooding threaten communities.
• Ecosystem Changes: Shifts in species distribution and phenology.

Responsibility Debate

The responsibility for addressing climate change is debated based on emissions:

• Annex 1 Countries (AC): Developed nations with higher historical emissions.
• Economies in Transition (EITs): Countries like Russia with transitioning economies.
• Least Developed Countries (LIDCs): Poorer nations with lower emissions but high vulnerability.

Emissions per Capita

• AC: High per capita emissions, significant historical responsibility.
• LIDCs: Low per capita emissions but suffer disproportionately from impacts.

Conclusion

Climate change is supported by robust evidence and driven by both natural and anthropogenic factors. Enhanced greenhouse gases, primarily from human activities, are intensifying global warming. While global impacts are widespread, responsibilities vary, with developed nations often bearing greater historical blame. Understanding these aspects is crucial for effective climate action.

Further Study: Explore mitigation strategies and adaptation measures for climate change.