Module 5 - Lecture 18

Introduction to Ecology

• Authors: Anne Houtman, Megan Scudellari, Cindy Malone

• Edition: NOW with Physiology, 2024

Objectives

• Define the biosphere and human roles within it.

• Differentiate between biotic and abiotic factors in ecology.

• Distinguish climate from weather.

• Describe the greenhouse effect, focusing on key gases.

• Compare the hydrologic cycle with the carbon cycle.

• Explain the contribution of global warming to climate change.

• List five consequences of climate change, detailing at least one.

• Articulate the significance of ecological footprints and assess your own.

Climate Meltdown

NASA’s Oceans Melting Greenland (OMG) Project

• Focus on tracking Greenland's ice sheet melting.

• Lead by Josh Willis; launched around 1,000 probes into coastal waters.

• Major findings indicate rapid melting due to climate change; Greenland owns the largest permanent ice sheet in the Northern Hemisphere.

Impacts of Ice Melting

• Expected sea-level rise of 23 feet if ice melts completely.

• Important cities (San Diego, New York, London) would be at risk of becoming uninhabitable.

• Previous estimates predicted a 1,000-year full melt; now, it may happen much sooner.

Factors Contributing to Melting

• Ocean impact possibly greater than atmospheric temperature.

• Probes measure water temperatures and radar assesses ice heights.

• Glacier dynamics include the balance of ice formation versus melting.

Ecology Fundamentals

Definitions

• Ecology: Study of interactions between organisms and their environment.

• Biosphere: Includes all organisms and the spaces they occupy, critical for human survival (food, water, etc.).

• Ecosystem: Interaction of biotic (living) and abiotic (non-living) factors.

Weather and Climate

• Weather: Short-term atmospheric conditions in a specific area.

• Climate: Average weather patterns over long periods (30+ years).

• Climate Change: Long-term alterations in climate patterns, primarily due to human activities.

Consequences of Climate Change

• Significant events linked to climate change: droughts, water scarcity, rising sea levels, and biodiversity loss.

Cycles in Nature

Hydrologic Cycle

• Water circulates between land and sky, predominantly near the equator.

• Process includes evaporation and precipitation.

• Transpiration: Plants release absorbed water into the atmosphere.

Carbon Cycle

• Carbon is exchanged between biotic (living organisms) and abiotic (physical environment) systems.

• Processes involved: photosynthesis, respiration, combustion, and decomposition.

• Carbon Sink: Absorbs more carbon than it releases.

• Carbon Source: Releases more carbon than it absorbs.

Impacts of Human Activity

Increasing Greenhouse Gases

• Recent significant increase in atmospheric CO2 levels due to fossil fuel burning.

• Correlation between CO2 levels and global temperatures observed.

• Oceans absorb a significant percentage of CO2 emissions, affecting marine health and acidity.

Melting Ice and Ecological Impacts

• Ice cores provide evidence of melting cycles; phytoplankton declines noted alongside warming waters.

• Rapid changes in glacial dynamics indicate feedback loops intensifying ice melt.

Climate and Seasonal Changes

• Earth’s tilt affects seasonal weather patterns.

• Greenhouse gases trap heat and contribute to global warming.

Ecological Footprint

• Definition: biologically productive land and water required to sustain individual populations.

• Average U.S. footprint is significantly high, indicating unsustainable resource use.