EE 22- Climate Change Effects on Biodiversity

Metrics of Local and Regional Climate Change (Garcia et al., 2014)

• Local Climate Change Metrics: Defined as temporal changes in climate parameters occurring within specific localities (grid cells). Key metrics include:     * Climate Anomalies: Changes in general climate conditions, such as temperature increases.     * Climate Extremes: Changes in the frequency or magnitude of events, such as more frequent droughts.     * Seasonality: Changes in the timing of climatic events, such as earlier Spring arrival.

• Regional Climate Change Metrics: Defined as temporal shifts in the distribution of climatic conditions across a broader region. Key metrics include:     * Area of Analogous Climates: Quantifying where specific climate classes shrink or expand.     * Novel Climates: The emergence of entirely new climatic conditions within a region.     * Distance to Analogous Climates: Measuring if similar climate classes are becoming geographically further apart.

• Global Projections: Assessment involves three primary dimensions:     * Location of Climate Change: Measured by magnitude, standardized local anomalies (range: $-0.10$ to $+0.90$ for temperature; $-0.05$ to $+0.95$ for precipitation), and probability of local extremes.     * Range of Climate Change: Measured by availability, change in area of baseline-analogous climates (range: $-100\%$ to $+5,445\%$), and emergence of novel climates.     * Velocity of Climate Change: The speed at which climatic conditions move across a landscape.

Linking Climate Metrics to Biodiversity Threats and Opportunities

• Individual Impacts: Decreased local climatic suitability directly affects individual physiology, morphology, and behavior.

• Population and Demographic Consequences: Shifts in timing (e.g., migration, breeding, and feeding) lead to demographic changes.

• Range Dynamics:     * Opportunity: Expanding climate area combined with low velocity of change allows for species range expansion.     * Threat: Shrinking climate area combined with fast velocity of change leads to range contraction.

• Community Shifts: Novel climates create novel species assemblages by altering biotic interactions and forcing range shifts.

Species Interactions and Community Dynamics (Boukal et al., 2019)

• Kinetic Effects of Warming:     * Metabolic Theory of Ecology: Warming increases kinetic energy, speeding up physiological processes.     * Direct Individual Effects: Impact on metabolic rate, locomotion, survival, and development rate.

• Lagged Responses: Warming causes delayed effects on behavior, phenology, and phenotypic traits, specifically:     * Shifts in phenology (timing of life events).     * Shifts in species ranges.     * Declines in individual body sizes.

• Interaction and Structure:     * Kinetic Interaction Effects: Increased feeding rates and higher prey mortality.     * Mismatches: Consumer-resource mismatches in both time and space.     * Community Level: Altered community composition, rewiring of food webs, and changes in food web stability.     * Ecosystem Function: Impacts on processes such as decomposition rates and dispersal patterns within metacommunities.

Species Vulnerability Assessment Framework (WWF)

• Sensitivity: The inability of a species to persist as climatic conditions change.

• Adaptive Capacity: The inherent ability of a species to respond or adjust to climate changes.

• Exposure: The extent and variation of climate change a species actually encounters (or is projected to encounter).

• Other Threats: The impact of external anthropogenic pressures that may compound climate-related stress (Advani, 2023).

Detailed

• Local Climate Change Metrics: Defined as temporal changes in climate parameters occurring within specific localities (grid cells). Key metrics include:
    - Climate Anomalies: Significant deviations from average climate conditions, which manifest as increases in temperature or unexpected weather patterns, leading to concerns about ecosystem stability.
    - Climate Extremes: An assessment of the increasing frequency or intensity of extreme weather events, such as prolonged droughts, heatwaves, or intense rainfall, that can profoundly impact natural and human systems.
    - Seasonality: Changes in the timing of climatic events, including earlier Spring arrivals or altered seasons, affecting biological processes such as flowering and migration, and ultimately influencing ecological interactions.   

• Regional Climate Change Metrics: Defined as temporal shifts in the distribution of climatic conditions across a broader geographical area. Key metrics include:
    - Area of Analogous Climates: A measured assessment of how regions classified under certain climate types either shrink or expand due to climate warming, providing insights into habitat changes for many species.
    - Novel Climates: The emergence of entirely new climatic conditions that did not previously exist in a region, posing challenges for species not evolved to cope with such abrupt changes.
    - Distance to Analogous Climates: Quantification of the geographical distance between similar climate classes, as this can indicate how species may need to move or adapt to survive in changing environments.
  

• Global Projections: Assessment is multidimensional, focusing on:
    - Location of Climate Change: Assessed by magnitude and standardized local anomalies for both temperature (range: $-0.10$ to $+0.90$) and precipitation (range: $-0.05$ to $+0.95$), along with the probability of experiencing local climate extremes, helping policymakers understand vulnerability areas.
    - Range of Climate Change: Measured by the availability and alteration in the area of baseline-analogous climates (ranging from $-100\%$ to +5,445 ext{%}), including projections for the emergence of novel climates.
    - Velocity of Climate Change: The pace at which climatic conditions alter across landscapes, critical for understanding the potential impacts on biodiversity and ecological resilience.