Climate change refers to the variations in climate ranging over a long span of time. It is one of the most critical global issues of the present times. In the past two and half centuries, there has been a consistent and alarming surge in the average temperature of the Earth.
An unprecedented increase in anthropogenic (human) activities since the industrial revolution is widely believed to have triggered the constant temperature rise. This rise in Earth’s average temperature is known as “global warming”. The global warming has resulted in extreme weather conditions, melting of glaciers, a rise in sea-level and erratic seasons etc.
Definition of Climate Change
According to the United Nations Framework Convention on Climate Change (UNFCCC) the climate change is defined as:
Climate change refers to a change of climate that is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and that is in addition to natural climate variability observed over comparable time periods.
In the above definition, UNFCCC makes a clear distinction between climate change caused by anthropogenic activities and climate variability caused by natural factors. This is different from the definition given by the Intergovernmental Panel on Climate Change (IPCC) which includes both natural variability and anthropogenic causes in its definition of climate change.
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According to the Intergovernmental Panel on Climate Change, the climate change is defined as:
Climate change refers to a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings such as modulations of the solar cycles, volcanic eruptions and persistent anthropogenic changes in the composition of the atmosphere or in land use.
History of Climate Change
We know it that climatic variations occur all the time while climate change occurs over a very large span of time, maybe across a thousand or even million-year time span. The occurrence of a warm and cold climatic period is not strange. In fact, geological records affirm such occurrences.
In the high latitude regions, traces of advances and retreats of glaciers have been found in the geomorphological features. Similarly, evidence of glacial lakes containing sediment deposits explains the occurrence of warm and cold periods at different time spans.
It is likely that Earth was a comparatively warmer terrestrial planet 500-300 million years ago, through Cambrian, Ordovician, and Silurian Periods. During the Pleistocene epoch, on the other hand, our Earth may have experienced a much colder average climate. The last major glacial period peak is estimated to have occurred around 18,000 years ago. The present period we are in; is an interglacial period which began nearly 10,000 years ago.
Why does Climate Change Happen?
The temperature of Earth is a balancing act. The energy budget of the Earth accounts for the balance between energy received by the Earth and the energy radiated back into space. It is important to maintain this balance between incoming and outgoing energy in order to meet the suitability for sustaining life on Earth. The climate change takes place when this otherwise balanced temperature of the Earth’s system undergoes change. Climate change can be both natural and human-induced.
Greenhouse effect is a natural process essential for maintaining the average temperature on Earth. Gases like water vapor, carbon dioxide, methane, etc. play an important role in trapping the heat from the solar radiation in the Earth’s atmosphere. This process keeps the temperature of Earth suitably warm. However, since the Industrial Revolution (1750), an unprecedented unnatural rise in the global average temperature has been observed owing to human activities. This has enhanced the greenhouse effect leading to a much-discussed phenomenon of global warming. The scientific community believes that the temperature of Earth has increased by about 1° C (1.8° F) since the beginning of the Industrial Revolution.
Causes of Climate Change?
As already mentioned above, causes of climate change can easily be categorized as natural or anthropogenic (human-induced).
Natural Causes of Climate Change
Prominent natural factors affecting Earth’s climate are as follows:
1. Variation in orbit of the Earth
The reach of sunlight falling on Earth’s surface is directly associated with the position of Earth on its orbit. Any variation in the orbit of the Earth influences the entire energy budget pattern of the Earth leading to climate change.
2. Volcanic Activities
Gases and dust particles released during volcanic eruptions partially block the incoming solar rays leading to a cooling of weather. While volcanic activities last only for a small span of time, the gases and dust released in huge quantities influence the climatic pattern for a long time.
3. Continental Drift
Continental drifts change the physical features of a landmass including its proximity with water bodies, direction, and strength of winds, the flow of winds, ocean currents, etc. The change in the overall physical feature ends up impacting the climatic pattern of the world.
4. Plate Tectonics
The horizontal and vertical displacements associated with plate tectonics greatly influence climate change over a long time span. The continuously evolving nature of the Earth’s surface and redistribution of landmass affects the balances of incoming and outgoing radiation.
Anthropogenic Causes of Climate Change
Climate studies have revealed that rapid climate change occurring in the present times is attributable to human activities to a large extent. Some of the main anthropogenic causes of the climate change are as follows:
1. Carbon Emission
Reasons like rapid industrialization, vehicular pollution, transportation, thermal power generation, and commercial-residential causes have all led to the excessive release of CO2 and other greenhouse gases into the atmosphere. The heat so trapped results in an unnatural increase in the temperature of Earth.
2.Burning of Fossil Fuel
The burning of fossil fuels like oil or coal emits a large amount of greenhouse gas. It is considered as one of the main reasons for global warming.
3. Change in Land Use
There exist a complex linkage between land use and climate change. Humans have interfered with the natural pattern of land distribution and diverted a large portion of land for agricultural use. Today, the total land under agricultural use exceeds the total area under forest. The shift in the pattern is both directly and indirectly linked to climate change.
It is one of the main human-induced drivers of climate change. Forest lands are permanently cleared for human settlement, agricultural and grazing purposes, timber, manufacturing, etc. This not only removes the vegetation which absorbs the carbon dioxide process from the air, but it also ends up emitting greenhouse gases during the process of removal of a forest.
Effects of Climate Change
Contemporary climate change is synonymous with the constant rise in Earth’s average temperature. The global average temperature of Earth is expected to rise by 11.5-degree Fahrenheit over the next century. Such a sharp rise in temperature will have devastating effects. Some of the major effects of the increased Earth’s temperature are discussed below.
1. Melting of Glaciers
Melting of glaciers is probably one of the strongest indicators of global warming and climate change. The size, spread, and balance of glaciers present some crucial information on climate. With the constant increase in temperature, glaciers have started to retreat at a very fast pace. This has eventually led to a noteworthy rise in the sea level. Any further significant rise in the sea level may devastate some coastal and island regions on the planet.
2. Rising Sea-Level
A sharp rise in sea level has been observed in the past two decades. It can be well understood from the facts that between 1870 to 2004, the sea level increased by 195 mm in total. On the other hand, it took an alarming sharp rise of 43 mm between 2004 until the present times.
3. Natural Disasters
Increase in the average surface temperature of Earth has increased the relative possibility of natural disasters like storms, drought, etc. A rise in temperature triggers more water evaporation, thereby increasing the likelihood of stronger and more devastating storms. Similarly, changes in seasonal and annual precipitation as a result of climate change has increased the odds of worsening droughts.
4. Impact on Vegetation
Climate change may vary the type and distribution of vegetation. Any rise in the temperature may lead to early blooming and fruiting of plants. This, in turn, may end up resulting in significant changes in the life pattern and cycle of living organisms.
5. Disturbed Food-web
Changes in the climate lead to changes in the food web of living organisms. Species will have to keep up its pace with the rapidly changing climatic conditions. Relative abundance or scarcity at any level can have devastating consequences for the entire food web.
6. Warming of Oceans
Excessive heat as a result of greenhouse gas emissions is mostly absorbed by the oceans. This absorption raises the temperature of the oceans in turn. Warming of the oceans triggers devastating storm and excessive rainfall leading to flooding.
7. Climate Change & Wildfires
Recent years have witnessed an unprecedented number of wildfires worldwide. Climate change has affected the weather and climatic conditions all across the globe. Factors like constantly rising temperature, change in rain and snow patterns and shifts in plant communities have all increased the risk of frequent wildfires.
8. Food Security Issues
Over a period of time, climate change has drastically impacted the food security of regions. It affects the entire food production process thereby limiting the food access. Climate change impacts and weather disasters inflate the food price of the available food. Such a price rise disproportionately affects the most vulnerable sections of society. Other risks include a decrease in the nutritional value of food and food waste due to unfavorable conditions.
9. Health Risk
Researchers believe that climate change also pose health risks. Changes in the natural air, water, food, and even sunlight can be easily observed all around us. These changes impact the general health conditions of individuals both directly and indirectly.
How to Tackle Climate Change
Climate changes are irreversible. The ongoing climate change can end up resulting in massive destruction. It is, thus, extremely important to appreciate that even though natural happenings cannot be controlled, human activities can be. We must strive to grow sustainably with climate change action going hand in hand. This is possibly the only way ahead.
On the front of climate change action, the following solutions may play a critical role.
1. Reduction in Carbon Emissions
The burning of fossil fuels for energy is still considered to be the top-most reason contributing to the increase in carbon dioxide concentrations. While carbon dioxide absorbs comparatively less heat than some other greenhouse gases, its presence in abundance combined with longer life-span in the atmosphere makes it an important factor triggering climate change. Therefore, Carbon Dioxide Removal (CDR) methods should be used to remove excess carbon dioxide from the atmosphere. These processes are also called Negative Emission Technologies. These technologies functions in such a way that more carbon dioxide is sequestered in the process than emitted.
2. Promotion of Renewable Energy
Renewable resources are inexhaustible. Nature replenished energy resources like wind, water, solar, etc. continuously. A shift from conventional-exhaustible sources of energy to cleaner-renewable energy is the need of the hour. Such a transition can play a critical role in avoiding the worst effects of the rising temperature.
3. Recycling & Waste Management
One of the easiest and effective solutions to reduce waste is to include the recycling and waste management process as a part of our consumption cycle. This will automatically take into account the reusability aspect of the production process.
4. Adaptation: Building Resilience
We can already feel the impact of climate change. Rising sea level, intense storms, regular natural disasters, irregular climatic variations are all the effects of climate change. Adaptation to the prospective changes, thus, requires more focus and brainstorming than ever. Building resilience of people and the ecosystem to deal with and adapt to the ongoing climate change is very important. Any delay in adaptation efforts will only prove to be more expensive and difficult. In order to ensure our readiness against climate change, we must opt for sustainable development with well-adapted and durable systems. Ideas and prospects of resilience shall find its due space in policies both at the national and international levels.