Climate change is one of the most discussed word now a days, among the gatherings, wherever people gather they talk about it. But, we don’t take steps to stop it.
The humans are major reason for earth’s climate change. The atmosphere is getting warmed. The glaciers are melting and there is rise sea level. Now there are departments in every country whom are dealing with this issue. So scientific information is necessary for communities to decide in accordance to and make policies.
Greenhouse gasses play important role in climate warming. Such as CO2 (Carbon dioxide) absorb the infrared radiation emitted from the earth’s surface. All of this is due to increased concentration of these gasses in the atmosphere. Roughly in last 100 years, the global average surface temperature has increased by 0.9 °C.
Along this the ocean is getting warmed. So, marked increase in sea level and decrease in arctic ice. All these events are due to increased concentration of greenhouse gasses.
Other greenhouse gasses like methane and nitrous oxide are also increasing. Human activities have disturbed the natural carbon cycle by buried fossil fuels and burning them for energy, thus releasing CO2 to the atmosphere.
In nature there is continuous exchange of CO2 in atmosphere by plants and humans. Plants release CO2 during photosynthesis and humans during process of respiration, it’s a natural cycle which is going on by nature.
The additional CO2 from burning of fossil fuel and deforestation has disturbed the balance of the carbon cycle, because the natural processes are too slow to restore the balance, compared to the rates at which human activities are adding CO2 to the atmosphere. Adding more CO2 to the atmosphere will cause surface temperatures to continue to increase.
As the atmospheric concentrations of CO2 increase, the addition of extra CO2 becomes progressively less effective at trapping Earth’s energy, but surface temperature will still rise. A very small amount of CO2 (1% of combustion of fossil fuel) is also emitted in volcanic eruptions.
This is balanced because CO2 is removed by chemical weathering of Rocky Mountains. The sun is primary source of energy to run this ecosystem. But it has very tiny role in climate change.
While at the same time global surface temperatures have increased. All major climate changes, including natural ones, are disruptive.
Past climate changes led to extinction of many species (like mammoth, black rhino and dinosaurs), population migrations, and pronounced changes in the land surface and ocean circulation.
The pace of the current climate change is much faster than most of the events in past, making it more deleterious for human societies and the natural world.
The observed warming rate vary from year to year, decade to decade and place to place, as is expected from our understanding of the climate system.
These short-term changes are mostly due to natural causes, and do not contradict our fundamental understanding that the long-term warming is primarily due to anthropogenic changes in the atmospheric levels of CO2 and other greenhouse gases.
Global warming is a long-term process, but that does not mean that every year will be warmer than the previous one. Day to day and year to year changes in weather patterns will continue to produce some unusually cold days and nights, and winters and summers, even as the climate warms. Sea ice is affected by winds and ocean currents as well as temperature.
Sea ice in the partly-enclosed Arctic Ocean seems to be directly responding to warming, while changes in winds and in the ocean seem to be dominating the patterns of climate and sea ice change in the ocean around Antarctica.
Earth’s lower atmosphere is becoming warmer and moister because of human-emitted greenhouse gases. This gives the potential for more energy for bad weathers such as storms and certain severe weather events.
Consistent with theoretical expectations, heavy rainfall and snowfall events (which increase the risk of flooding) and heat waves are generally occurring more frequently. Extreme rainfall varies from region to region. There are also changes in the global sea level, the rise in level of tide is 0.12 inches per year.
The overall rise for 100 years is about 8 inches at global level. All these results are due to climate warming. There are changes in ocean water chemistry as well.
The pH of water is becoming lower, going towards acidic, so the sea creatures whom are composed of minerals like corals are composed of calcium carbonate they are getting dissolved readily, so it became very difficult for them to maintain their shells.
Even though an increase of a few degrees in global average temperature does not sound like much, global average temperature during the last ice age was only about 4 to 5 °C (7 to 9 °F) colder than now.
Global warming of just a few degrees will be associated with widespread changes in regional and local temperature and precipitation as well as with increases in some types of extreme weather events. These and other changes (such as sea level rise and storm surge) will have serious impacts on human societies and the natural world.
Authors: Hammad Ur Rehman Bajwa1,*, Muhammad Kasib Khan1, Arsalan Zafar1, Saad Salman Khan1, Abdullah Khalid Chatha1
- Department of Parasitology
University of Agriculture, Faisalabad, Pakistan