What do we mean by Climate Change?
Climate change refers to long-term changes in the Earth’s climate patterns, including changes in temperature, precipitation, and weather events. These changes are primarily caused by human activities that release large amounts of greenhouse gases into the atmosphere, such as burning fossil fuels for energy and transportation, deforestation, and agriculture.
Greenhouse gases are gases in the Earth’s atmosphere that trap heat and contribute to the greenhouse effect, which causes the Earth’s temperature to rise. The main greenhouse gases include:
- Carbon dioxide (CO2)
- Methane (CH4)
- Nitrous oxide (N2O)
- Chlorofluorocarbons (CFCs)
- Hydrofluorocarbons (HFCs)
- Perfluorocarbons (PFCs)
- Sulfur hexafluoride (SF6)
Carbon dioxide is the most well-known and abundant greenhouse gas, primarily released by burning fossil fuels, deforestation, and land use changes. Methane is the second most important greenhouse gas, and it is primarily released by agriculture, livestock farming, and natural gas production. Nitrous oxide is mainly released through agricultural practices such as fertilizers and manure management. CFCs, HFCs, PFCs, and SF6 are synthetic gases used in various industrial applications, such as refrigeration, air conditioning, and electronics.
The accumulation of these greenhouse gases, such as carbon dioxide, methane, and nitrous oxide, trap heat in the atmosphere and cause the Earth’s temperature to rise, leading to a wide range of environmental and social impacts, including rising sea levels, more frequent and severe weather events, changes in ecosystems, and health risks to humans and other living beings. Addressing climate change is considered one of the most pressing challenges facing the world today.
Rise in Sea levels
A rise in sea level refers to an increase in the average height of the Earth’s oceans and seas. Sea levels can rise due to a variety of factors, such as the melting of land-based ice (e.g., glaciers, ice caps, and ice sheets) and the thermal expansion of seawater due to global warming. When sea levels rise, the water level can encroach on low-lying coastal areas, leading to increased flooding, erosion, and saltwater intrusion into freshwater resources. This can have a wide range of environmental and social impacts, including the loss of land, damage to infrastructure, and displacement of people. Sea level rise is considered one of the most significant impacts of climate change and is projected to continue for centuries to come, even if greenhouse gas emissions are reduced significantly in the near term.
How much of Sea level rise is a threat?
The amount of sea level rise that poses a threat depends on various factors, including the location and vulnerability of coastal communities, the rate of sea level rise, and the ability of society to adapt to changing conditions. However, as a general rule, even small increases in sea level can lead to significant impacts, particularly in low-lying areas and small island nations.
According to scientific research, global sea level has risen by about 8-9 inches (20-23 cm) since the late 19th century, and the rate of rise has accelerated over the past few decades. The United Nations Intergovernmental Panel on Climate Change (IPCC) has projected that global sea levels could rise by 0.26 to 0.77 meters (0.85 to 2.5 feet) by the end of the century, depending on future greenhouse gas emissions and other factors.
What are impacts of Sea level rise?
Sea level rise of this magnitude would have significant impacts on coastal areas, including increased flooding, erosion, and saltwater intrusion into freshwater resources. It could also lead to the displacement of millions of people and the loss of critical infrastructure, including ports, airports, and power plants. In short, any sea level rise can be a threat, and urgent action is needed to reduce greenhouse gas emissions and adapt to the changing conditions.
Coastal areas around the world are currently facing sea level rise
Some examples of places on Earth currently facing sea level rise include:
- Small island nations: Many small island nations, such as the Maldives, Tuvalu, and Kiribati, are particularly vulnerable to sea level rise due to their low-lying geography and dependence on coastal resources.
- Coastal cities: Major coastal cities, such as Miami, New York, Mumbai, Shanghai, and Bangkok, are also facing sea level rise and its impacts, including increased flooding and storm surge.
- Low-lying deltas: Low-lying river deltas, such as the Ganges-Brahmaputra Delta in Bangladesh and the Mekong Delta in Vietnam, are at risk of flooding and saltwater intrusion due to sea level rise.
- Arctic and Antarctic regions: The Arctic and Antarctic regions are also experiencing rapid sea level rise due to the melting of land-based ice sheets and glaciers.
- Coastal regions with high tides or storm surges: Some coastal regions with high tides or storm surges, such as the Bay of Bengal and the Gulf of Mexico, are also facing increased flooding and erosion due to sea level rise.
How to scientists monitor sea level rise?
Scientists monitor sea level rise through a combination of satellite-based measurements, tide gauges, and other observational methods. Here are some of the main ways that sea level rise is monitored:
- Satellite altimetry: Scientists use satellite altimetry to measure sea surface height and track changes over time. This involves bouncing radar signals off the ocean surface to determine its height relative to the center of the Earth. Satellites can provide global coverage and data on sea level change over large areas, making them a valuable tool for monitoring sea level rise.
- Tide gauges: Tide gauges are devices that measure the height of the ocean relative to a fixed point on land. Scientists use tide gauges to track changes in sea level over time, as well as to provide data for modeling sea level rise and predicting future changes.
- GPS stations: GPS stations can be used to measure changes in land elevation due to changes in the weight of ice and water on the Earth’s surface. By tracking changes in land elevation relative to sea level, scientists can estimate the contribution of land-based ice melt to sea level rise.
- Oceanographic measurements: Scientists also collect oceanographic data, such as temperature and salinity, to better understand the factors contributing to sea level rise. For example, changes in ocean temperature and salinity can affect the density of seawater, which in turn can affect sea level.
- Modeling: Scientists use computer models to simulate past, present, and future sea level rise based on a range of scenarios. These models incorporate data from satellite altimetry, tide gauges, GPS stations, and other observational methods to help improve our understanding of sea level rise and its impacts.
By using a combination of these methods, scientists can track sea level rise and its impacts on coastal areas and communities, and help inform policy and adaptation efforts to mitigate its effects.