Climate Change and Greenhouse Gases Quiz

Climate Change Overview

• The lecture material is the intellectual property of Dr. Neil J. Porter. Distribution or publication of this material is illegal under Canadian Copyright law.
• The lecture covers climate change, natural hazards, and disasters, part of the ESCI-1000 course.

Climate Change: Overview

• The current climate is warming.
• Warming is based on decades of atmospheric warming.
• Global temperature and sea levels are increasing.
• Snow, glaciers, ice sheets, and permafrost are melting.
• Earth's climate systems interact: Atmosphere, Hydrosphere, Geosphere, Cryosphere, and Biosphere.

Climate Change: 9.0 Climate, Weather, and the Atmosphere

• The climate is currently warming.
• Warming is attributed to decades of atmospheric warming.
• Also, there is a global increase in sea temperatures with widespread melting of snow, glaciers, ice sheets, and permafrost.
• The earth's climate encompasses the interactions of the atmosphere, hydrosphere, geosphere, biosphere, and cryosphere.

Climate Change: Global Warming

• A 99% probability exists that human activity is responsible for global warming.
• Ecosystems can adapt, but changes occur too quickly.
• Global air temperatures have increased by 0.8°C (1.4°F) since 1865.

Climate Change: Weather and Climate

• Weather is the short-term state of the atmosphere.
• Climate is the long-term average weather pattern.
• Earth's temperature depends on the amount of sunlight received, the amount of sunlight reflected, and how much heat the atmosphere retains.

Climate Change: Greenhouse Effect

• The greenhouse effect is a natural and necessary process.
• Without it, all surface water would be frozen, and little life would exist.
• Water vapor accounts for 66-85% of the greenhouse effect.
• Greenhouse gases (carbon dioxide, methane, nitrous oxide, CFCs, and ozone) enhance the greenhouse effect.

Climate Change: Atmospheric Composition

• Atmospheric gas concentrations that do not change include nitrogen (78.08%) and oxygen (20.95%).
• Other atmospheric gases, such as water vapor (0.2-4%), carbon dioxide (0.038%), and methane (0.00017%), vary over time and space.
• Nitrogen is relatively unimportant to atmospheric dynamics.

Climate Change: Carbon Dioxide

• Carbon dioxide is a small percentage of the atmosphere.
• It occurs naturally through volcanic activity, plant and animal respiration, wildfires, and organic material decay.
• It is removed by photosynthesis, chemical weathering, and absorption by seawater.
• Burning fossil fuels by humans greatly increased CO2 levels since the Industrial Revolution.

Climate Change: Carbon Dioxide in the Atmosphere

• Atmospheric carbon dioxide levels have increased significantly in recent times.
• Temperature variations and atmospheric CO2 concentration show a high correlation, implying strong connections.
• Recent changes in climate likely result from human activities more than from natural causes.

Climate Change: Methane

• Methane is a major constituent of natural gas.
• It occurs naturally through bacterial decay, termite, cow, and sheep intestinal tracts.
• Human sources include coal mines, oil wells, leaking natural gas pipelines, rice cultivation, landfills, and livestock.
• Methane levels have doubled since 1700 and are a significant contributor to warming.

Climate Change: Ozone

• Ozone forms when atomic oxygen collides with oxygen molecules.
• Mostly found in the stratosphere, it acts as a shield for ultraviolet light.
• Ozone depletion increases skin cancer, cataracts, and could cause localized crop failures..

Climate Change: Aerosols

• Aerosols are microscopic liquid or solid particles.
• They act as nuclei for water condensation to form clouds by interacting with air pollution.
• Natural aerosols include dust, wildfires, sea spray, and volcanoes.
• Anthropogenic aerosols result from burning forests and fossil fuels.
• Aerosols have complex effects on climate.

Climate Change: Paleoclimatology

• Paleoclimatology is the study of past climates.
• Proxy data is used to reconstruct past climates.
• Natural recorders analyze climate variability.

Climate Change: Dendroclimatology

• Dendroclimatology uses tree rings to collect climate data.
• The growth of trees depends on rainfall and temperature.
• Tree ring records extend back by more than 10,000 years.

Climate Change: Sediment Records

• Sediment records reflect past climates.
• Pollen types found in sediment layers are preserved for analysis.
• Sediment layers can be independently dated to create chronological records.

Climate Change: Historical Records

• Historical records (books, newspapers, and records that have been maintained) can provide information on temperature and precipitation.
• Detailed records of carbon dioxide in the atmosphere date back to 1958.

Climate Change: Short-Term Scale Changes

• Solar energy from the sun varies over time.
• Luminosity, sunspots, and faculae are connected to short-term solar cycles.
• There is no strong correlation between solar activity and average Earth temperature.
• Milankovitch theories explain the cycles and variations in Earth's orbit that cause glacial and interglacial periods.

Climate Change: Volcanic Activity

• Volcanic eruptions affect climate by releasing ash into the atmosphere.
• The ash reflects sunlight, causing a cooling effect.
• The 1815 eruption of Mount Tambora led to a cooling period in North America and Europe.

Climate Change: International Agreements

• The 1987 Montreal Protocol aimed to limit ozone depletion by CFCs.
• CFCs have decreased since the protocol was adopted.
• The 1997 Kyoto Protocol established targets for nations to reduce greenhouse gas emissions.
• Nations like Canada have made international commitments, but the US withdrew, affecting the agreement's effectiveness.
• The 2000 Hague summit aimed to find new methods for balancing carbon emissions.

Climate Change: Carbon Sequestration

• Carbon sequestration captures and stores carbon dioxide to prevent atmospheric entry.
• Processes include planting more trees, injecting carbon deep into the ocean, or using power plants and industrial facilities with CO2 capture technology.

Climate Change: Future Scenarios

• Two climate change scenarios for the next 100 years are offered.
• Both scenarios anticipate population growth and economic expansion.
• Scenario 1 projects high fossil fuel use resulting in a 4.5°C temperature increase, while Scenario 2 projects a 2°C increase.
• The associated sea-level rise values differ accordingly.

Climate Change: Impacts and Hazards

• Sea surface temperatures have risen since the 1970s and deep ocean water has also increased.
• Ocean conveyor belt circulation keeps northern Europe warmer compared to areas without it.
• Warmer sea water fuels hurricanes and the intensity of storms.
• Recent Atlantic hurricanes reflect a severity increase; however, overall global tropical storm frequency hasn't changed.
• Climate patterns are changing, including frequency/intensity of violent storms, and El Niño/La Niña events.
• Ice melting (Greenland and Antarctic ice sheets, glaciers, ice caps) and ocean expansion are significant contributors to rising sea levels.
• Arctic sea ice loss is observed, leading to amplified warming due to reduced albedo.
• Impacts include: Changes to polar bear survival, dwindling food sources for human Arctic dwellers, and marine species migration.
• Climate change models accurately represent conditions only if human emissions are considered.
• The concentration of atmospheric CO2 was about 280 ppm in 1750 and likely will reach at least 460 ppm by 2050.
• Dissolved atmospheric CO2 acidifies oceans making it unable for marine organisms to form their shells (Coccolithophores, Foraminifers, Sea urchins, and corals).
• Human-induced degradation precedes and accompanies vegetation loss and erosion, decreasing the land's productivity.
• Increased drought frequency and severity are projected.
• Increased wildfires in regions with ecosystems poorly adapted to warming.