Page 59 - 全球气候变化及其影响Global Climate Change and Its Impacts-185×260

Chapter II Evidence for Global Climate Change

paths and intensity of hurricanes and other tropical cyclones. Traditionally, hurricanes typ-
ically follow specific paths influenced by ocean heat content distribution. However, some
anomalous paths observed in recent years may be attributed to changes in this distribution.
For example, increased temperatures in deeper ocean layers within certain regions have al-
tered ocean circulation patterns, consequently affecting hurricane path selection. Simultane-
ously, uneven vertical distribution of ocean heat content may also cause hurricanes to rapidly
intensify when approaching land, increasing hazards during landfall.
(D) Increase in the Frequency of Extreme Weather Events
In addition to increased intensity, global warming may also lead to a rise in the fre-
quency of hurricanes and other tropical cyclones. Although current research has not yet fully
established this conclusion, existing evidence suggests that the number of tropical cyclones
might undergo changes under climate warming. Specifically, some regions may experience
more intense hurricane strikes, while other areas might see fewer but more powerful storms.
This changing trend reflects both the impacts of climate change on global atmospheric circu-
lation patterns and the differential climatic responses across geographical regions.
(V) Socioeconomic and Ecosystem Impacts
The intensification of hurricanes and other tropical cyclones poses significant chal-
lenges to human societies and ecosystems in coastal areas. First, powerful hurricanes cause
immense destructive forces, resulting in severe casualties and property damage. During the
2017 Atlantic hurricane season, super hurricanes such as Harvey, Irma, and Maria made
successive landfalls in the United States and Caribbean regions, causing economic losses
amounting to tens of billions of US dollars. Second, frequent hurricane activity exacerbates
coastal erosion, threatening beaches, wetlands, and other critical ecosystem services. Over
the long term, intense hurricanes also alter sediment distribution at river estuaries, impacting
fisheries resources and biodiversity.

Section 4 Long-Term Trends and Abrupt Changes in
Climate Change

I. Identification and Analysis Methods for Long-Term Climate Change
Trends
In climate change research, accurately identifying the long-term trends of climate
change from long-term climate data sequences is crucial, as it provides the foundation for
understanding the evolution patterns of the climate system and predicting future climate
changes. Various methods are employed in this research, with linear regression and moving
averages being the most commonly used approaches.
Linear regression is a statistical method widely applied to identify long-term climate
change trends. Its core principle lies in constructing a linear equation by minimizing the

• 51 •