Climate Science: Earth's Temperature and Energy Balance

Study Notes

Earth's Temperature and Energy Balance

Earth's temperature depends on the balance between incoming solar energy and outgoing heat.
Incoming solar energy is absorbed, warming the Earth.
Energy released back into space cools the Earth.

Factors Affecting Earth's Energy Balance

Natural factors include volcanic activity and changes in solar output.
Human activities, since the Industrial Revolution, are a significant factor, largely responsible for recent rapid warming.

Historical Climate Data

Scientists analyze proxy data (ice cores, tree rings, etc.) to understand past climate.
Ice cores are crucial sources of climate information, containing atmospheric gases from past centuries.
Natural climate variability includes cycles of warming and ice ages.

The Greenhouse Effect

Greenhouse gases (GHGs) like CO2, CH4, and water vapor absorb outgoing infrared radiation.
This process traps heat, making Earth warmer than it would be without an atmosphere.
Human activities have increased GHG concentrations since the Industrial Revolution.

Greenhouse Gases

Primary GHGs emitted by humans: CO2, methane, nitrous oxide, fluorinated gases, and water vapor.
Global warming potential (GWP) measures the heat-trapping ability of a gas.
Relative warming effect considers the gas's concentration.

Carbon Dioxide (CO2)

CO2 is the primary GHG driving recent climate change.
Human activities (fossil fuel burning, deforestation) release large amounts of CO2.
Atmospheric CO2 levels have increased significantly since pre-industrial times (from ~280 ppm to over 410 ppm in 2018).
Historical CO2 emissions are significantly less than today's human released CO2, (over 135 times as much as volcanoes).

Methane (CH4)

Methane has a much higher GWP than CO2 (28 times more heat-trapping than CO2).
Sources include wetlands and human activities (animal agriculture).
Atmospheric methane concentrations have increased significantly since pre-industrial times.

Nitrous Oxide (N2O)

N2O has a high GWP (300 times more heat-trapping than CO2).
Agriculture (synthetic fertilizers & manure) are main human-caused sources.

Fluorinated Gases (F-gases)

F-gases are entirely human-made and have very high GWPs, as high as 22,000 times that of CO2.
Used as substitutes for ozone-depleting substances (like CFCs). Stricter regulations are in place from international agreements.

Water Vapor

Water vapor is the most abundant and naturally important GHG, but its concentration is heavily influenced by temperature.
Human activity has a much smaller effect on water vapor levels globally.

Other Climate Change Factors

Solar Activity: Solar output has been relatively stable in the last half century so it is not responsible for current warming.
Changes in Reflectivity (Albedo): Reflecting surfaces reflect more sunlight (higher albedo) while absorbing surfaces absorb more sunlight (lower albedo). Albedo changes include melting ice, cloud cover, and aerosols, which can cool or warm the earth.

Future Climate Change Projections

Increased GHG concentrations lead to further warming and changes in precipitation, storms, ice, snow, permafrost, sea level, and ocean acidification.
Changes in each of these factors have cascading effects and disproportionately affect developing nations.
These effects will continue even if emissions are stopped, as long-term warming mechanisms (like ocean warming) persist.

Future Temperature Changes

Models predict continued warming over the 21st century and beyond

Future Precipitation and Storm Events

Precipitation patterns and frequency are likely to change, with variations regionally.
More intense precipitation events are also projected.

Future Ice, Snow, and Permafrost

Arctic sea ice, snow cover, and permafrost are expected to continue to decline.
Melting glaciers and ice sheets contribute to sea level rise.

Future Sea Level Change

Sea level rise is driven by thermal expansion of water, melting glaciers and ice sheets.
Regional variations in sea level rise will occur based on local geological factors, like subsidence and uplift.

Future Ocean Acidification

Increased atmospheric CO2 leads to ocean acidification that could threaten marine ecosystems.
Projected effects of the decreased pH impact marine organisms.

Spread of Disease

Warmer global temperatures expand the range and accelerate the lifecycle of disease-carrying insects.
This will lead to the spread of diseases like dengue fever, malaria, and others.

Climate Justice

Climate change disproportionately affects developing nations.
Support and policies are required to address the impacts of climate change in developing nations.

Mitigation and Adaptation

Reducing greenhouse gas emissions, and adapting to climate changes is necessary to minimize impact.
Individual choices and political action are needed for mitigation and adaptation.

Description

This quiz explores the complex interactions that determine Earth's temperature and energy balance, including natural and human-induced factors. It examines the significance of greenhouse gases and historical climate data, focusing on their roles in influencing climate change. Test your knowledge on these vital environmental concepts!