Climate change is defined as the shifting of world’s climate due to increase of earth temperature. the  increase  of  average  temperature  in the earth  atmosphere  is  mostly bring  by the concentration  of greenhouse gases such as methane , carbon dioxide  and  other  traces  element  which is harmful and poisonous .it is known  that  greenhouses   gases  are  beneficial  to existence of human  kind  for  the maintenance  and  the  balance  of  the warm within  the  earth  surface- the  sun  produce  sun rays  which  has  a hotness  of more than  6000C^o , afer than  sun  light  rays  leave the  sun’s  surface 55% of it  is  reflected  by the  ozone layer : which is  a  colorless gas  mostly O₃  soluble  in  al kalis  and cold  water  and  it acts  as   screen  for ultra violet  radiation  the  rest  of 45%    percent  5% of  it  is  reflected  by the greenhouse gases , dust particles  which  is present mechanically  within the  atmosphere

For  the  last fourth   decades  climate  change  has been  an issue  of concern as  the continuous  rapid population  growth , depletion  of ozon layer  shown  an obvious impact  to existence  of mankind  and this is why  the sessions  of environmental  affairs  were  given  great priority  at the united nation as  the most  of the countries   across  the world confronts perpetuation  of disparities  between and within  nations , a worsening  of poverty , hunger , ill health  and illiteracy  and the continuous  deterioration  of the ecosystem  on which we depend  for our  wellbeing. The sessions  and  the  conference  organized  by the  united  nation  take   a obvious  role  for  the elimination  of factors  that  contributes  climate change  or  may accelerates its impact  .  the  developed  countries  make  a commitment to  provide assistance  aids  to  the  developing  and  those who suffers   economic crises  especially in the third  world  countries . This aids include subsides , capacity  building , consultations,  awareness  and  other facilitations . this in turn  led  to  s the innovation   of other  alternative  source  of energy  to reduce  fossil fuels  and  emission  of chlorofluorocarbon  to the atmosphere  which  causes  great  damge  to the ozon layer  which is  an important layer   for the absorption  of ultra violet  radiation  form the  sun . the projects   pioneered by the united  nation  were  benefited  by  developing  countries   especially  the African  while  the  others  rejected   among  those  rejected  include  india  and  the lied countries  across the Asian  continents .

Climate  change  affects  people in  far reaching –ways .impacts  related  to climate  change are evident  across the world  and many sectors important  to society – such as  human health ,  agriculture , food security , water supply ,  transportation , energy  ecosystem  and others – and are  expected  to increasingly  disruptive  throughout this  century  and  beyond . climate  change  affects human  health  and  wellbeing  through more  extreme  weather  events  and  wildfires ,  extreme , decreases  air quality  and diseases transmitted  by insects . climate  disruptions  to agriculture  have been increasing  and are projected  to become  more  severe  over this century , a trend  that  would  diminish  the  security  of food  supply  in many parts  of the world . surface and  ground  water  supplies  in some  regions  are already stressed  and  water  quality  is  diminishing . in some  regions prolonged  periods  of high temperatures associated  with  droughts  contribute to  condtions that lead to larger  wild fires  and longer fire  seasons . for coastal community  sea level rises , combined  with  coastal storms  has increased  the risk of ersion , extreme  heat  sea level  rise and  heavy down pour  are  affecting  infra structures like roads  rail lines  and military  bases . in other  word  siome  climate  change  currently have beneficial  effects  for specific sectors  or regions . for example current benefits  of warming  include longer  growing  seasons for agriculture  and longer ice –free seasons  for shipping on the  great  lakes at  the same however , however  longer growing seasons  along  with high temperatures  and  carbon dioxide   level  can increase pollen production . as we mentioned  before  climate  is caused  by the  increase of the greenhouse  gases   which is due  by human activity . the main causes   can be seen from the following ;

Burning coal , oil and gas: the  burning  of coal  and  gas produces  carbondioxide  and nitrous oxide  which is harmful gases

Cutting down forest: it is known  that trees  help  to regulate  the climate by absorbing  CO2  and  other  green house gases  from the atmosphere .  so when they are cut down that   beneficial effect is lost  and  the carbon stored  in trees is released  into the  atmsopshere  adding to the green house effect

Increasing  livestock  farming :   cows and sheep produce large  amount of methane  when  they digest their  and  this in turn adds  effect to the green  house gases

Fluorinated gases : produce a very strong  warming  effect , up to 23000t time greater than carbond dioxide