CLIMATE CHANGE EAES

Drivers of Climate Change

Factors that alter Earth's energy balance and climate over time.

Natural Drivers of Climate Change

Variations in solar radiation, Milankovitch cycles, volcanic activity, and asteroid impacts.

Anthropogenic Drivers of Climate Change

Greenhouse gas emissions, deforestation, land use changes, urbanization, and pollution.

Feedback Loops

Processes that amplify climate change, such as melting ice decreasing albedo and leading to more warming.

Incoming Solar Radiation

Mostly shortwave UV radiation from the sun that interacts with Earth’s atmosphere.

Albedo

A measure of how much sunlight is reflected by a surface.

Milankovitch Cycles

Natural variability caused by changes in Earth’s orbit affecting climate over tens of thousands of years.

Greenhouse Gases (GHGs)

Gases in the troposphere that trap heat by absorbing and re-emitting infrared radiation.

Main Greenhouse Gases

Carbon dioxide (CO₂), Methane (CH₄), Nitrous oxide (N₂O), and Water vapor (H₂O).

Potent GHGs

Methane (CH₄) is ~25x stronger than CO₂ over 100 years; N₂O and fluorinated gases are also potent.

Atmospheric Lifetime of CO₂

Decades to centuries.

Atmospheric Lifetime of CH₄

Approximately 12 years.

Atmospheric Lifetime of N₂O

Approximately 114 years.

Tropospheric Ozone (O₃)

Found near the Earth’s surface and formed from human-related sources; acts as a GHG.

Stratospheric Ozone

Found high in the atmosphere and protects Earth by absorbing high-energy UV rays.

Radiative Forcing

The measure of a factor's effect on Earth’s energy balance, in W/m².

Positive Radiative Forcing

Indicates warming, such as from greenhouse gases.

Negative Radiative Forcing

Indicates cooling, such as from aerosols or volcanic ash.

Sources of GHG Emissions

Natural sources include respiration and wetlands, while anthropogenic sources include energy production and transportation.

Natural Sources of GHGs

CO₂ from respiration, CH₄ from wetlands, and N₂O from oceans and soils.

Anthropogenic Sources of GHGs

Includes energy production, transportation, industry, agriculture, and deforestation.

Climate Change Predictions for BC

Projected changes in temperature and precipitation patterns in British Columbia.

Temperature Changes in BC

Most warming expected in BC’s Interior, with positive anomalies across all regions.

Precipitation Changes in BC

Southwestern coast to become hotter and wetter; the interior to become hotter and drier.

Biogeoclimatic Zone Shifts

Expected changes in ecological zones due to climate variations.

Bunchgrass Expansion

Expected to expand into drier, hotter valleys due to climate changes.

Interior Douglas Fir Expansion

Will expand with warmer temperatures.

Alpine Tundra Retreat

Alpine tundra is expected to shrink and be replaced by forests at higher elevations.

Spruce Zones Retreat

Spruce zones will retreat to northern and higher elevation areas.

Human-related Sources of Ozone

Formed from nitrous oxides, VOCs, and sunlight.

Black Carbon

A type of particulate matter that contributes to positive radiative forcing.

Volcanic Activity

Can impact climate through eruptions that release aerosols.

Urbanization and Greenhouse Gases

Urban development contributes to increased greenhouse gas emissions.

Changes Over Time in Forcing Factors

Last 250 years saw a massive increase in anthropogenic positive forcing.

Fossil Fuel Use

A major source of anthropogenic GHG emissions.

Agricultural Emissions

Contributes methane from livestock and nitrous oxide from fertilizers.

Deforestation as a GHG Source

Loss of carbon sinks contributing to increased GHG concentrations.

Waste Management and GHGs

Landfills release methane during the decomposition of organic waste.

Variability in Climate Predictions

Increased precipitation variability leading to more intense storms or droughts.

Climate Change Impact on Ecosystems

Expected shifts in species and habitat distributions due to changing climate conditions.