eChapter Name: Impact of Climate Change on Aquatic Ecosystems and Fisheries in Kashmir Valley: Challenges and Adaptation Strategies
9789367554197
eBook Name: AQUATIC ECOSYSTEM IN COLD REGION
Introduction
Climate change refers to alterations in the earth's global or regional climates over time, encompassing shifts in atmospheric variability or average conditions over periods ranging from decades to millions of years. The United Nations Framework Convention on Climate Change (UNFCCC) differentiates between "climate change" for human-induced alterations and "climate variability" for other changes. Over the past century, ending in 2005, the average global air temperature near the earth's surface has risen at an estimated rate of 0.74 ± 0.18°C (1.33 ± 0.32°F) (IPCC, 2007). In contemporary discussions, especially within environmental policy, "climate change" often refers to recent climate alterations. Both natural processes and human activities influence the earth's temperature and subsequent climate change. Significant increases in global anthropogenic greenhouse gas (GHG) emissions over the years have been major contributors to global warming. The sun, the earth's primary energy source, has a nearly constant output, but minor variations over extended periods can lead to climate change. Natural processes such as orbital changes (orbital forcing), volcanic eruptions, and greenhouse gas concentrations in the atmosphere also affect the earth's climate. Changes in atmospheric concentrations of greenhouse gases and aerosols, land cover, and solar radiation modify the climate system's energy balance, leading to either warming or cooling.
Volcanic eruptions release several gases, notably sulfur dioxide (SO2), which forms sulfate aerosols (SO4) in the atmosphere. Although linking specific weather events to global warming is challenging, increased global temperatures can result in broader changes like glacial retreat, Arctic shrinkage, and rising sea levels worldwide. Variations in precipitation patterns could lead to floods and droughts. Other impacts may include shifts in agricultural yields, the creation of new trade routes, reduced summer stream flows, species extinctions, and the spread of disease vectors. Most global climate change models predict a decline in snowpack on many western mountain ranges, adversely affecting fish populations, hydropower, water recreation, and water availability for agricultural, industrial, and residential use. Partial loss of polar ice sheets could lead to significant sea level rise, altering coastlines and inundating low-lying areas, with the most significant effects on river deltas and low-lying islands. These changes are projected over millennial timescales, but rapid sea level rise within centuries cannot be ruled out. Current climate change models predict a rise in sea surface temperatures between 2 °C and 5 °C by 2100 (IPCC Third Assessment Report, 2001; Done et al., 2003). According to the climate profile document of Jammu and Kashmir, the region has seen an increase in average temperature, with the Kashmir valley rising by 1.45°C and the Jammu region