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Global Climate Change and Its Impacts

Australia’s 2019-2020 “Black Summer” fires that burned vast forest areas, releasing massive
amounts of carbon previously stored in trees. Additionally, activities like illegal logging and
agricultural expansion continue to reduce forest coverage, diminishing terrestrial ecosystems’
capacity to absorb atmospheric carbon dioxide.
Ocean Acidification: As the oceans absorb excessive carbon dioxide, the seawater
pH decreases, leading to coral bleaching and mortality of other marine organisms, which
disrupts the structure and function of marine ecosystems. Concurrently, changes in marine
microbial communities may reduce their carbon sequestration capacity, thereby affecting the
entire marine carbon cycle.
[2] Wetland Degradation
Wetlands, as one of the most efficientcarbon sinks on Earth, can store vast amounts of
organic carbon long-term. However, due to drainage projects, agricultural development, and
accelerated urbanization, many wetlands have been destroyed or converted to other uses,
weakeningtheir carbon sequestration capacity。
(2) Impaired Water Regulation Functions
Healthy ecosystems play irreplaceable roles in maintaining water cycle balance, includ-
ing water conservation, flood control, and water purification. Climate change-induced alter-
ations in precipitation patterns and increased extreme weather events have subjected these
service functions to unprecedented challenges.
[1] Declining Water Conservation Capacity
Vegetation-covered areas such as forests, grasslands, and wetlands can effectively inter-
cept precipitation, replenish groundwater, and maintain river flow. However, due to activities
like deforestation and wetland drainage, the water conservation capacity in many regions
has significantly declined, leading to increasingly prominent water resource shortages. For
example, in some arid areas of western China, severe grassland degradation caused by over-
grazing and increased irrigation water use has exacerbated local water scarcity.
2.Increased Flood Risk
Global warming has led to more frequent extreme rainfall events, while urbanization
processeshaveimpervioussurface ratiosincreasing, further accelerating surface runoff veloci-
ty and flood potential. Meanwhile, aging flood control infrastructure and inadequate mainte-
nance have constrained response capabilities, making flood disasters more devastating.
3.Water Quality Deterioration
Climate change may also indirectly affect water quality. For instance, rising tempera-
tures can promote algal blooms, exacerbating eutrophication; heavy rainfall washes pollut-
ants from soil into water bodies, contaminating drinking water sources. Additionally, saltwa-
ter intrusion caused by sea level rise threatens freshwater resource supplies in coastal areas.
(C) Weakening of Soil Retention Functions
Soil retention refers to the anchoring of soil particles by plant roots to prevent geologi-
cal hazards such as erosion and mudslides. Good soil conditions hold significant importance

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