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Chapter Three Impacts of Global Climate Change

2.Ocean Acidification
The increase in atmospheric carbon dioxide concentration leads to ocean acidification,
affecting the survival and reproduction of marine organisms. Ocean acidification has partic-
ularly significant impacts on shellfish (such as oysters, clams, and corals), as their shells and
skeletons are primarily composed of calcium carbonate, and acidified seawater weakens cal-
cium carbonate formation. For example, oyster aquaculture in the Pacific region has suffered
severe losses due to ocean acidification, reducing local residents’ protein sources.
3.Decline in Fishery Resources
Ocean warming and acidification have led to reduced fishery resources, threatening
regions that rely on seafood as a primary protein source. For instance, residents of Pacific
island nations typically depend on fish and shellfish as staple food sources, while the degra-
dation of marine ecosystems has severely jeopardized their food security.

Section IV Regional Differences and Vulnerability Assess-
ment of Climate Change Impacts

I. Regional Differentiation Patterns of Climate Change Impacts

The impacts of climate change exhibit significant disparities across different global
regions, which fundamentally result from the comprehensive interaction of various factors
including geographical, climatic, and ecological elements.
From a geographical perspective, latitude plays a fundamental role in shaping regional
climate change variations. High-latitude regions such as the Arctic and Antarctic are par-
ticularly sensitive to climate change. The temperature in the Arctic has been rising at a rate
significantly higher than the global average, primarily due to its unique geographical charac-
teristics. The reduction of sea ice cover serves as a prominent manifestation of Arctic climate
change. Sea ice possesses high albedo that reflects substantial solar radiation. As climate
warming accelerates ice melt, the solar radiation previously reflected by sea ice is absorbed
by the ocean, elevating seawater temperatures and further accelerating ice melt – forming a
positive feedback mechanism. These changes have profoundly impacted Arctic ecosystems,
reducing habitats for ice-dependent species like polar bears and causing population declines.
In low-latitude tropical regions, while temperature increases are relatively smaller, alter-
ations in precipitation patterns exert significant impacts. Some tropical areas face reduced
rainfall and intensified droughts, severely affecting their agriculture-dependent economies.
For instance, in several tropical African countries, droughts have caused crop yield reduc-
tions or complete failures, triggering food security crises. Additionally, topography serves as
another crucial geographical factor. Mountain ranges obstruct and uplift air currents, altering
regional precipitation distribution. On windward slopes, forced uplift of air currents leads
to cooling condensation and abundant rainfall, while leeward slopes form rain shadow areas

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