-> Introduction:
Climate change, as the name suggests, is a change in the climatic conditions on the Earth. There is a frequent variation in the weather however climate change is known to occur only if these variations last from a few decades to centuries.
-> What is climate change?
Climate change is the significant and lasting change of our weather over sustained periods of time. There is international consensus that human activities over the last 50 years have altered the Earth's natural climate. Excess production of greenhouse gases and changes to our natural ecosystems (such as deforestation) are contributing to global warming. Intergovernmental Panel on Climate Change has concluded that:
• Ecological changes due to global warming "are likely to affect the health status of millions of people"
• People with less ability to respond to the environmental and public health impacts of climate change will be most impacted
• It is "virtually certain" that there will be warmer and more frequent hot days and nights
• It is "very likely" that the frequency of heat waves will increase over most land masses
> Causes of Climate Change
Climate change is caused due to various external and internal mechanisms. Let us learn about these in detail:
✓ External Forcing Mechanisms
1. Volcanic Eruption
Volcanic eruptions that emanate more than 100,000 tons of SO2 in the stratosphere are known to bring about climatic changes on The Earth. These eruptions cool down the Earth's atmosphere for a couple of years as they bar the transmission of solar radiation to the Earth's surface to some extent.
2. Solar Output
The rate at which the Earth receives energy from the Sun and the rate at which the energy is emitted back in the space determine the climate and equilibrium temperature on the Earth. Changes in the solar output thus impact the global climate.
3. Plate Tectonics
The motion of tectonic plates generates topography by reconfiguring the land and oceans over a period of millions of years. This impacts the climatic conditions globally.
4. Orbital Variations
Changes in the Earth's orbit lead to changes in seasonal distribution of sunlight received on it. Orbital changes are of three types. These include changes in the Earth's eccentricity, changes in the tilt angle of the Earth's axis of rotation and precession of the Earth's axis. These cause Milan kvetch cycles that have a huge impact on the climate.
5. Human Activities
The increasing emission of CO2 due to fossil fuel combustion, vehicular pollution, deforestation, animal agriculture and land use are some of the human activities that are causing climate change.
✓ Internal Forcing Mechanisms
1. Life
Life impacts climate by playing a role in carbon emission and water cycles. It also impacts the climatic conditions by way of mechanisms such as cloud formation, weathering and evaporate transpiration among others.
2. Ocean-Atmosphere Variability
Together, the atmosphere and ocean bring about changes in the internal climate. These changes can stay from a few years to a few decades and impact the global surface temperature.
Effects of Climate Change
Climate change is having negative repercussions on the Earth's environment. Here is a look at its effects:
1. Effect on Forests
Forests are important to maintain the environmental balance as they soak carbon dioxide. However, several species of trees are unable to withstand the changing climate and have become extinct. Mass extinction of trees and plants has led to decrease in the level of biodiversity which is bad for the environment.
2. Effect on Polar Region
The north and south poles of our planet are critical for regulating its climate and these are particularly impacted due to the changing climatic conditions. If the changes continue like this, it is anticipated that the life in polar region may go extinct in the times to come.
3. Effect on Water
Climate change has led to some serious issues in the water systems across the globe. The rainfall patterns have become extreme due to the changing weather conditions and this causes flood and drought conditions in different parts. The melting of glaciers due to the rise in temperature is another major issue.
4. Effect on Wildlife
The number of various wild animals including tigers, African elephants, Asian rhinos, Adeline penguins and polar bears has gone down and most of these
species are on the verge of getting extinct as they cannot cope up with the changing weather.
5. Effects on Coastal Areas
Climate changing also affects glaciers. The water from glaciers is gradually melting. Thus, the water level of seas is rising at very fast speed. The coastal areas are in so much trouble due to rising level of water. The most affecting areas are Karachi, Singapore, Kolkata and shanghai etc.
6. Agricultural Food (Food insecurity)
Agriculture production is also decreasing due to severest floods and soil erosion. The crops are destroyed by heavy rains and floods leading to food insecurity and low yield in the country.
7. Health Problems
Health problems are also another affect of climate changing. Heat stroke and heart problems are caused by increasing temperature. Every year, almost a large number of populations of Pakistan are suffering from increasing temperature.
> Strategies to mitigate climate changing
1. To plant native, drought-resistant trees and shrubs around homes and outdoor air conditioning unit
2. Replacement of current home appliances (refrigerator, washing machine, dish washer) with high-efficiency models
3. Improving the energy efficiency of buildings to reduce emissions from
heating/cooling
4. Planting forests and tree to remove excess carbon dioxide from our atmosphere
5. Reducing fuel emissions associated with motor vehicles
COMPOSED BY TALAT MAHMOOD
