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Global Climate Change and Its Impacts

extensive artificial surfaces (e.g., concrete, asphalt) absorbing and storing solar radiation.
The urban heat island effect not only influences local climates but may also trigger
chain reactions on regional and global climates. For instance, rising temperatures in urban
areas could lead to increased energy consumption (e.g., air conditioning usage), thereby
elevating greenhouse gas emissions. Furthermore, urbanization alters surface hydrological
cycles, increasing surface runoff while reducing groundwater recharge, ultimately affecting
regional precipitation patterns and ecosystem health.
(IV) Potential Impacts of Land Use Change
Land use change is one of the significant pathways through which terrestrial surface
processes affect the climate system. Human activities such as agricultural expansion, defor-
estation, and urban sprawl alter the natural characteristics of Earth’s surface, consequently
impacting climate. For instance, agricultural expansion typically involves deforestation and
land reclamation, leading to reduced vegetation cover,carbon sink capacitydecline, and in-
creased surface albedo.
Deforestation not only reduces carbon sinks but also undermines ecosystem stability
and biodiversity. Forests serve as crucial water source conservation areas and climate regula-
tors – their destruction may lead to regional climate changes and ecosystem degradation. Ad-
ditionally, agricultural activities (such as irrigation and fertilization) also affect soil moisture
and greenhouse gas emissions, thereby influencing climate.
Urban expansion affects local and regional climates by altering surface characteristics and
energy balance. Buildings and infrastructure in urban areas modify surface albedo and thermal
capacity, leading to temperature increases and changes in precipitation patterns. Urbanization
may also influence wind speed and direction, further altering regional climatic conditions.

Section 2 Natural Drivers of Climate Change

Several major natural drivers in the Earth system, including solar activity, volcanic
eruptions, and variations in Earth’s orbital parameters, have historically exerted profound
influences on global climate change. By analyzing these natural phenomena and their mech-
anisms, we can develop a more comprehensive understanding of the climate system’s com-
plexity and variability, while providing crucial scientific foundations for predicting future
climate changes.

I. Variations in Solar Radiation

As Earth’s primary energy source, changes in solar radiation intensity have a directand
significant impact on Earth’s climate.Impact. Solar radiation is not constant but exhibits
periodic fluctuations, primarily manifested in sunspot activity cycles and other long-term
variation patterns. There is a correlation between the number of sunspots and solar radiation
output, typically completing a full activity cycle approximately every 11 years, known as the

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