Earth 4 Flashcards
What is the albedo effect?
The albedo effect measures the reflectivity of a surface. Light-colored surfaces (e.g., fresh snow) reflect more sunlight, cooling the planet, while darker surfaces (e.g., oceans) absorb more sunlight, warming the planet.
How does the albedo effect influence Earth’s climate?
High-albedo surfaces reflect sunlight, reducing heat absorption, while low-albedo surfaces absorb sunlight, increasing heat. Seasonal changes and ice melting can alter Earth’s overall albedo.
What is the difference between positive and negative feedback loops in climate systems?
Positive Feedback Loop: Amplifies changes, causing instability (e.g., melting ice reduces albedo, increasing warming). Negative Feedback Loop: Reduces changes, promoting stability (e.g., increased cloud cover reflecting sunlight).
What role does the albedo effect play in positive feedback loops?
When temperatures rise, ice melts, exposing darker surfaces like water or soil. These absorb more sunlight, further increasing temperatures, and accelerating ice melt.
What is permafrost, and where is it found?
Permafrost is ground that remains frozen for at least two consecutive years. It is found in large regions of the Northern Hemisphere, covering about 25% of its landmass.
Why is permafrost important in the context of climate change?
Permafrost contains vast amounts of organic material and greenhouse gases like methane and carbon. When it melts, these gases are released, accelerating global warming.
What are two main impacts of permafrost melting?
Release of greenhouse gases like methane, which is 12 times more potent than carbon dioxide. Destabilization of land, leading to infrastructure damage.
Why is methane a more potent greenhouse gas than carbon dioxide, and why do we focus on CO2?
Methane absorbs heat more effectively than CO2 but has a shorter atmospheric lifetime. CO2 is more abundant and stays in the atmosphere longer, making it a bigger long-term concern.
What effect do animals and vegetation have on permafrost?
Animals like reintroduced mammoths could trample vegetation, which helps prevent snow accumulation. Less snow increases surface cooling, which could help preserve permafrost.
How does melting permafrost contribute to the recent warming trend?
Melting permafrost releases methane and carbon dioxide, enhancing the greenhouse effect and contributing to accelerated warming.
Why are fewer trees desirable in Siberian permafrost regions?
Fewer trees reduce insulation from snow cover, allowing the ground to stay cooler and helping to preserve the permafrost.
How can the albedo effect help mitigate climate change?
By increasing high-albedo surfaces (e.g., ice, snow), more solar energy is reflected back into space, reducing heat absorption.
