TOP 10 CAUSES OF CLIMATE CHANGE

DEFINITION OF CLIMATE CHANGE

According to UNFCCC the definition of climate change is -It is a change of climate that is attributed directly or indirectly to human activity,altering the  composition of global atmosphere.

FACTOR AFFECTING CLIMATE CHANGE

Natural Factor

• Extraterrrstrial factor like variation in the sun's activity and slow change in the earth orbit and  slight tilt of its axis.According modern scientists-It is no coincidence that an increase in sun spot activity and run-up of global temperature on the earth happening currently and hence, the blame of global warming on natural variation in the sun's output due to sunspots and solar wind.
• The seasonal distribution of sunlight reaching to earth surface  is directly related to earth orbit and a slight variation in the Earth orbit leads to variation in the distribution across the globe.
• The main influence within the earth is volcanism ,when the volcano erupt-the erupted matter like gases ,solids,dusts particle particularly block the incoming rays of the sun which leads to cooling of the weather.Volcanic eruption have large but transitory negative effect.
• Plate tectonics also one of the reason for climate change-slow drift of continent and mountain also influence the climate but it takes millions of year for a slight change.
• factor operating on the earth surface include the reflectivity or albedo of the surface :The amount of heat in the ocean and atmosphere and the level of heat exchanged between them, and the influence of land vegetation on the composition and the heat balance of the atmosphere.
• Atmospheric factor include the composition of the atmosphere and its reflectivity,from the surface of the earth to the stratosphere.

Ocean Current

The ocean covers 71% of planet and hold 97% of water and making the ocean a key factor in the storage and transfer of the heat energy across the globe.The movement of this heat through local and  global ocean current affect affect the regulation of the local weather conditions and temperature extremes ,stabilization of global climate patterns,cycling of gases and delivery of nutrients and larva to marine ecosystem.

ANTHROPOGENIC  FACTOR/MAN MADE FACTOR

Anthropogenic factor or man made factor result in short term climatic change

Greenhouse Gases

• Since the industrial revolution began around 1750 ,human activity have contributed substantially to climate change by adding carbon-dioxide and other heat trapping gases to the atmosphere.These greenhouse gas emissions have increased the greenhouse effect and cause the earth temperature to rise.
• The primary human activity affecting the rate and amount of climate change is greenhouse gas emissions from burning of fossil fuels.

CARBONDIOXIDE

• Carbon-dioxide is the primary greenhouse gas that is contributing the recent climate change and it is absorbed and emitted naturally as a part of the carbon cycle through plant and animal respiration ,volcanic eruptions and oceanic atmosphere exchange.
• Human activities such as the burning of fossil fuels and changes in land use ,release large amount of carbon-dioxide cause its high concentration in the atmosphere. 
• In 2013 carbon-dioxide level surpassed 400 ppm for the first time in recorded history.

METHANE

• Methane is produced through both natural and human activities.For example natural wetland ,agricultural activity and fossil fuel extraction and transport all emit methane.Methane is more abundant in earth atmosphere now than at any time in the least the past 80,000 years.Due to human activity methane concentration is increased sharply during most of 20th century and are now more than two-and-a-half times pre-industrial levels.in recent decades ,the rate of increase has slowed cosiderably.

NITROUS OXIDE

• Nitrous oxides produced through natural and human activity,mainly through agricultural activities and natural biological processes.Fuel burning and some other processes also produces nitrogen oxides and increases its concentration in the atmosphere ,it has risen risen approximately 20% since the start of industrial revolution with a relative rapid increase toward the end of 20th century.

WATER VAPOR

Water vapor is the most abundant green house gas and also the most important gas on the earth ,it also contribute lot toward green house effect,but it has having short atmospheric life span.Some human activity can influence the local water vapor levels.However on global scale the the concentration of water vapor is controlled by temperature which include overall rate of evaporation and precipitation.

TROPOSPHERIC OZONE

• It has a short atmospheric lifespan and a potent greenhouse gas .Chemical reaction create ozone from emmissions of nitrogen oxides and volatile organic compound from automobiles,power plants,and other industrial and commercial sources in presence of sunlight in addition to trapping heat ,ground level ozone is pollutant that can cause respiratory health problem and damage crops and ecosystems.

F GASES

• Chloroflourocarbons (CFCs),hydrochloroflourocarbon (HCFCs),hydroflourocarbons (HFCs),perflourocarbon(PFCs) and sulphur hexa flouride together called F gases are often used in coolant ,foaming agents,fire extinguisher,solvents,pesticides,and aerosol pollutants.Unlike water vapor and ozone ,these F gases have a long atmospheric lifetime,and some of these emission  will affect the climate for many decades or centuries.

AEROSOLS

• The tiny particle that are present in the atmosphere called aerosols ,also play crucial roles in weather and climate .Atmospheric aerosol can be either solid or liquid with diameters few nanometers to10 micron .
• There are two broad classes of aerosols -Primary aerosols are generated or emitted as solid particles 
• for example normal dust ,sea salt or soot.
• Secondary aerosols are formed in the atmosphere by chemical reactions-such as ammonium solphates aerosols are formed from the gases of sulphur dioxide and ammonia,while organic aerosols are formed by chemical reaction acting on chemicals such as isoprene emitted by plants.
• It have the ability to influence the climate directly by absorbing and reflecting incoming sunlight and they have the ability of indirect effect on climate by changing in cloud formation or modification in cloud property ,another big problem is that-it can be transported thousand of kilometre by wind.