Environmental Science 101: Climate Change - Evidence of Climate Change Temperature Records Ice Cores Sea Level Rise Extreme Weather

What This Is

Climate change is a pressing global issue driven by human activities that alter the Earth's energy balance, leading to rising temperatures, melting ice, and extreme weather events. The greenhouse effect, where certain gases trap heat, is the primary driver of current warming. For instance, the 2019-2020 Australian bushfires, which burned over 10 million hectares of land, are a stark example of the devastating consequences of climate change.

Key Concepts, Laws & Models

• Greenhouse Effect: The trapping of heat by certain gases in the atmosphere, leading to a global average temperature increase of 1°C since the late 19th century. Real-world implication: The 2019-2020 Australian bushfires were exacerbated by rising temperatures.
• Global Temperature Records: The longest continuous temperature record, maintained by NASA and the National Oceanic and Atmospheric Administration (NOAA), shows a steady increase in global temperatures since the late 19th century. Real-world implication: The 2020 European heatwave, which saw temperatures reach 48.8°C in France, is a manifestation of this trend.
• Ice Cores: The analysis of ice cores from Antarctica and Greenland reveals a clear record of past climate conditions, including temperature, CO2 levels, and volcanic eruptions. Real-world implication: The ice core record shows that CO2 levels have increased by 40% since the Industrial Revolution.
• Sea Level Rise: The global sea level has risen by 15-20 cm since 1900, primarily due to the melting of glaciers and ice sheets. Real-world implication: The 2018 King Tides in Miami, which saw water levels reach 1.5 meters above the high tide mark, are a consequence of sea level rise.
• Extreme Weather Events: The increasing frequency and severity of extreme weather events, such as heatwaves, droughts, and heavy rainfall, are linked to climate change. Real-world implication: The 2017-2018 California wildfires, which burned over 1.2 million hectares of land, were exacerbated by rising temperatures and drought.
• Climate Models: Computer simulations that project future climate scenarios based on different emission scenarios and climate sensitivity. Real-world implication: The Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (2014) projected a 2-5°C temperature increase by 2100 under different emission scenarios.
• Carbon Cycle: The process by which carbon is exchanged between the atmosphere, oceans, land, and living organisms. Real-world implication: The burning of fossil fuels has increased atmospheric CO2 levels by 40% since the Industrial Revolution.
• Ocean Acidification: The decrease in ocean pH due to the absorption of CO2 from the atmosphere, which affects marine ecosystems and the global carbon cycle. Real-world implication: The 2019-2020 coral bleaching event in the Great Barrier Reef was exacerbated by ocean acidification.
• Climate Feedback Loops: Self-reinforcing processes that amplify or dampen climate change, such as the melting of Arctic sea ice, which exposes darker surfaces and accelerates warming. Real-world implication: The 2020 Arctic heatwave, which saw temperatures reach 38°C in Siberia, is an example of a climate feedback loop.
• Climate Sensitivity: The equilibrium temperature response to a doubling of CO2 levels, which is a key parameter in climate models. Real-world implication: The IPCC Fifth Assessment Report (2014) estimated a climate sensitivity range of 1.5-4.5°C.

Step-by-Step Application

1. Calculate a carbon footprint using the IPCC's carbon footprint calculator, which takes into account emissions from energy, transportation, and land use.
2. Evaluate an environmental impact assessment (EIA) by considering the potential environmental impacts of a proposed project, such as habitat destruction, water pollution, and greenhouse gas emissions.
3. Predict population growth using the rule of 70, which estimates the number of years it takes for a population to double based on its annual growth rate.
4. Analyze the effects of climate change on a specific region or ecosystem using climate models and scenario planning.
5. Develop a climate change adaptation strategy for a community or organization, considering factors such as sea level rise, extreme weather events, and changing precipitation patterns.

Common Misconceptions

• Misconception: "Climate change is a natural phenomenon and not caused by human activities."
• Correction: The overwhelming scientific evidence shows that human activities, particularly the burning of fossil fuels and deforestation, are the primary drivers of climate change.
• Misconception: "Renewable energy has no environmental impact."
• Correction: While renewable energy sources like solar and wind power have lower environmental impacts than fossil fuels, they can still have environmental effects, such as land use changes and wildlife impacts.
• Misconception: "Climate change is a local issue and not a global problem."
• Correction: Climate change is a global issue that requires international cooperation and action to mitigate and adapt to its impacts.

Exam/Free-Response Tips

• Be aware of common multiple-choice traps, such as "all of the above" or "none of the above," which can be used to eliminate incorrect answers.
• Use the "SOAPS" framework to structure your free-response answers: Situation, Observation, Analysis, Prediction, and Solution.
• Be able to distinguish between weather and climate, as well as primary and secondary succession.
• Use specific examples and data to support your arguments and predictions.

Quick Practice Scenario

A farmer applies excessive nitrogen fertilizer to their crops, leading to runoff that reaches a nearby lake, causing an algal bloom. Which nutrient cycle is disrupted, and what secondary effect will deplete oxygen?

Answer: The nitrogen cycle is disrupted, leading to an overabundance of nitrogen in the lake, which will stimulate the growth of algae, depleting oxygen levels.

Last-Minute Cram Sheet

• "El Niño" is not the same as "La Niña" – El Niño is the warm phase; La Niña is the cool phase, and both are part of the ENSO cycle.
• The greenhouse effect is the primary driver of current warming.
• The 2019-2020 Australian bushfires were exacerbated by rising temperatures.
• The IPCC Fifth Assessment Report (2014) projected a 2-5°C temperature increase by 2100 under different emission scenarios.
• The carbon cycle is the process by which carbon is exchanged between the atmosphere, oceans, land, and living organisms.
• Ocean acidification is the decrease in ocean pH due to the absorption of CO2 from the atmosphere.
• Climate feedback loops are self-reinforcing processes that amplify or dampen climate change.
• Climate sensitivity is the equilibrium temperature response to a doubling of CO2 levels.
• The rule of 70 is used to estimate the number of years it takes for a population to double based on its annual growth rate.
• The Paris Agreement aims to limit global warming to well below 2°C and pursue efforts to limit it to 1.5°C above pre-industrial levels.